Joji's space
editI am working as a Deputy Manager in a MNC company Bangalore. I completed my Diploma and Bachelor Degree in mechanical Engineering. I have more than 11 years experience and knowledge in all the MEP works ( Electrical,HVAC,PHE & FFW,Lifts,Gas Piping,LV systems etc.). i am from a small village called pandalam in Kerala,India
MEP Engineer
edit- MEP- Mechanical Electrical processing.
- 'MEPI- Mechanical Electrical processing and Instrumentation.
- Mechanical Includes HVAC,Fire Fighting and plumbing.
- Electrical includes all electrical works
- Processing includes processing plants like STP
==Abbrevations commonly using in MEP==
Abbrevations Description
- MEP - Mechanical Electrical processing
- XLPE - Cross linked polyethylene
- FMP - Floor Main Panel
- SDB - Sub Distribution Board
- LUX - Unit of illumination
- FRLS - Flame resisted Low smoke
- MCCB - Moulded Case Circuit Breaker
- ACB - air circuit breaker
- UPS - Uninterrupted Power supply
- AMF - Auto Main Failure
- EPABX - Electronic Private Automatic Branch Exchange
- CCTV - Closed circuit Television System
- HT/V Panel - High tension/Voltage Panel
- VVVF - variable voltage variable frequency
- FAR - Floor area ratio.. Total build up area/ Total plot size
- BOD - Bio chemical oxygen demand
- COD - Chemical oxygen demand
- FHR - Fire Hose reel
- PHE - Public Health Engineering(Plumbing)
- STP - Sewage Treatment Plant
- WR - Wet riser
- DR - Dry Riser
- REIA - Rapid Environment Impact assessment
- EPCG - Export Promotion custom goods
- CAACO - Chemo- Auto trophic Activated Carbon Oxidation System (STP)
- VFD - Variable frequency drives
- LPD - Litre per day
- LPCD - litres per capita demand
- PAX - Passengers/Persons
- AHU - Air handling unit
- FCU - Fan coil Unit
- BTU - British Thermal Unit
- ECWT - Entering condensor water temperature
- GPM - Gallons per Minute
- DB - Distribution board
- PTZ - Pan Tilt Zoom
- ASHRAE - American Society for Heating Refrigerating and Air conditioning Engineers
Working Of AC
editAn air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner. The term Freon is generically "used for any of various nonflammable fluorocarbons used as refrigerants and as propellants for aerosols."
File:AC working.jpg
Diagram of a typical air conditioner
This is how the evaporation cycle in an air conditioner works . The compressor compresses cool Freon gas, causing it to become hot, high-pressure Freon gas (red in the diagram above). 1. This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a liquid. 2. The Freon liquid runs through an expansion valve, and in the process it evaporates to become cold, low-pressure Freon gas (light blue in the diagram above). 3. This cold gas runs through a set of coils that allow the gas to absorb heat and cool down the air inside the building. Mixed in with the Freon is a small amount of a lightweight oil. This oil lubricates the compressor. So this is the general concept involved in air conditioning.
HVAC Dictionary
edit- Acidize When acid is used to remove mineral and iron deposits (scale) to restore heat transfer efficiency.
*Air Balance Test A test used to measure airflow across a tower or air handler system. *Air Balancing Hood Measures airflow from grilles and diffusers.
- Amp (Ampere) The practical meter-kilogram-second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm.
- Amp/Ohm/Volt Meter Measures motor amperage and voltage test controls.
- ARI Air Conditioning and Refrigeration Institute
- Baseline Data Baseline (or historical) data is compiling past chiller logs for review.
Basin Cold water reservoir in the cooling tower system.
- Basin Temperature The actual temperature of the cold water basin in the cooling tower system.
- Bearing A support or guide by means of which a moving part such as a shaft or axle is positioned with respect to the other parts of a mechanism.
Bearing Oil Reservoir Excess oil used in the lubrication of the bearing system located in the compressor system. *Biocide A substance (as DDT) that is destructive to many different organisms.
- Blockage Blockage is obstruction of flow, i.e., valve, debris, etc.
- Boroscope A fiber-optic camera or lens, used to inspect tube bundles or piping.
- BTU British thermal unit. The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit.
- Bypass Valve A valve used to detour flow, i.e., to detour water from the hot deck to the tower basin to control tower basin temperature.
- Carryover The movement of a fluid from one area to another. Carryover of this liquid may contaminate another liquid, causing undesired results.
- Chill Water Chill water is the water in the closed loop (closed to the atmosphere) or evaporator system of the chiller.
- Chiller
(Centrifugal Chiller) A heat exchanger using air, refrigerant, water and evaporation to transfer heat (BTUs) to produce air conditioning (measured in tons). A chiller is comprised of an evaporator, condenser and compressor system.
- Chiller Barrel Passes Many chillers are designed with more than one pass to maximize heat transfer. Baffels and gaskets are used to separate each pass to ensure design flow through the chiller barrel.
*Chiller Design Tonnage The design capacity of the chiller measured in tons produced in an hour.
- Chiller Efficiency Chiller efficiency is measured in Kilowatts per ton (Kw/Ton) of cooling produced. The higher the Kw/Ton, the lower the heat transfer efficiency and the higher the cost to produce a ton of cooling.
- Chiller Log Sheet A sheet on which specific chiller readings are documented.
- Chiller Manufacturer The company that built the chiller, i.e., York, Trane, Carrier, McQuay, etc. The manufacturer name is typically prominently displayed on the chiller control panel or technical documentation.
- Chiller Stall A chiller stalls when the refrigerant is no longer moving through the compressor and there is no cooling effect. All shaft work is being converted into heat in the compressor that may lead to permanent damage.
- Chiller Startup The chiller manufacturer’s recommendation on startup including pre-heating the compressor oil temperature prior to chiller startup.
- Chiller Surge When the refrigerant flows backwards through the compressor wheel every few seconds until the pressure builds up and the refrigerant moves forward again. This is even more dangerous than a stall because it reverses loads of thrust bearings in the compressor shaft.
- Chiller Vane
(Inlet Guide Vanes) Chiller vanes are used to control the capacity of the compressor. As the inlet guide vanes start to close, they change the gas entry angle to the impeller and reduce gas flow and compressor capacity. As the vanes near the closed position, they throttle the refrigerant flow.
- Closed Loop The evaporator side of the chiller system, closed to the atmosphere.
- Compressor A mechanical device where the refrigerant is compressed from a lower pressure and lower temperature to a higher pressure and higher temperature. The compressor maintains a low pressure in the evaporator by continually removing refrigerant vapors. This low pressure, low temperature vapor is then compressed into a higher pressurize, hot refrigerant vapor which leaves the compressor and travels to the condenser. The motor in the compressor is the main consumer of energy in the chiller system. The energy used by the compressor is dependent on the pressure increase. The head pressure divided by the suction pressure or the condenser pressure divided by the evaporator pressure expresses this. If the compressor operates out of its original design, it will effect the energy consumption.
- Compressor Erosion/Corrosion Damage to the bearings and impeller caused by poor lubrication, low oil levels or operating conditions such as liquid refrigerant carryover into the compressor system.
- Compressor Motor Amps The energy used to power the refrigerant cycle in a chiller system. The input energy is dependent upon the pressure increase in the compressor. The head pressure divided by the suction pressure or the condenser pressure divided by the evaporator pressure determines it.
- Compressor Oil Temperature Compressor oil temperature is the temperature of the oil in the compressor bearing lubrication system. This temperature is predetermined by manufacturers specifications.
*Condensation The process a vapor goes through to change phase from vapor to a liquid.
- Condenser Heat exchanger where the system heat is rejected and the refrigerant condenses into a liquid. The condenser is where hot pressurized refrigerant vapors in the compressor are cooled and liquefied by cooling tower water circulating through the tubes of the condenser. The condenser side is commonly referred to as the open recirculation system or open loop.
Condenser Delta P The pressure drop between the suction side and the discharge side of a chiller barrel. This pressure drop can be measured against known values from tables/charts to determine water flow through the chiller barrel. Delta P is dependant on chiller tube ID and tube length.
- Condenser Delta T The temperature difference between the entering and leaving water through the chiller barrel. i.e., the entering temperature is 85°F and the leaving temperature is 95°F then the delta T would be 10.
- Condenser Water GPM
(Gallons Per Minute) The velocity of the condenser water measured in gallons per minute. All chiller condensers have a manufacturers design GPM flow rate.
- Condenser Pressure The head pressure produced in the condenser dependent on the entering condenser water temperature and the saturated refrigerant temperature. The condenser pressure can affect the refrigerant cycle and heat transfer. The pressure correlates to saturated refrigerant temperature on a pressure/temperature chart for each refrigerant type.
- Condenser Refrigerant Approach Temperature The refrigerant temperature minus the leaving water temperature. The refrigerant temperature can be determined by locating the condenser (head) pressure on a pressure/temperature chart, or if the chiller control panel provides this information.
- Condenser Water The open recirculating system connects the chiller condenser to the cooling tower system and the atmosphere. Condenser water is subject to evaporation, debris/contamination, fouling/scaling and microbio growth.
- Conditioned Fluid The fluid being acted upon by the working fluid. Example: in an air conditioning system the air is conditioned by the refrigerant (refrigerant is the working fluid).
- Constant Speed Drive Constant speed drives are the most common type of chiller compressor motor. They have limited ability to adjust speed based on part load conditions.
- Contamination Any foreign object or substance not normally found in a specific location.
- Cooling Tower Where the process of heat exchange occurs by evaporation in the open recirculating system. The cooling tower system includes tower fans, plenum, drift eliminators, fill, levelers, hot deck and cold basin. All cooling towers have a design rated delta temperature.
- Approach Temperature The difference between the leaving water temperature and the entering air wet bulb.
- Cooling Tower Fan Fan system designed to remove the heat generated by the open recirculating system through evaporation.
- Cooling Tower Fill Designed to brake up the circulating water into smaller particles or a thin film. This increases the surface area of the water to enhance evaporation and heat removal.
- Cooling Tower/Condenser System The cooling tower system includes tower fans, plenum, drift eliminators, fill, levelers, hot deck and cold basin combined with the condenser barrel and piping making up the open loop or open recirculating system.
- Corrosion The decay and loss of a metal due to a chemical reaction between the metal and its environment. It is a transformation process in which the metal passes from its elemental form to a combined (or compound) form.
- Cost of Blowdown The total cost of water sent to drain/sewer, typically determined on a per 1,000 gallon basis. This value can be found on the water and sewer utility bill or from the utility company.
- Cost of Kw The cost of electricity charged by the electric and is typically $0.04 to $0.15 per kilowatt depending on geographic location.
- Cost of Makeup The total cost of water added to the condenser/cooling tower system, typically determined on a per 1,000 gallon basis. This value can be found on the water and sewer utility bill or from the utility company.
- CPLV – Calculated Part Load Value The calculated Kw/Ton derived from the effect of part load and entering condenser water temperature on the chiller when compared to full load design.
*Dead Leg A static condition that exists over a period of time in equipment or system that has no water flow. This condition is usually associated with lay-up and can promote the growth of microbes and corrosion.
- Debris Anything the environment can introduce that is washed out by the tower operations, i.e., dirt, trash, chip scale “flash corrosion”, bugs, broken tower fill, broken tower wood, plastic, etc.
- Delta P The pressure drop between the discharge side and the suction side of a chiller barrel. This pressure drop can be measured against design values provided by the chiller manufacturer or previously developed charts by plant personnel to determine water flow through the chiller barrel.
- Delta T The temperature difference between the entering and leaving water through the chiller barrel, i.e., entering temperature is 85°F, leaving temperature is 95°F = delta T10°F. If the actual water flow is known, delta P could determine a problem if the actual delta P does not match the current water flow.
- Design Amps (Full Load) The maximum amp load on the chiller. This information can be found in the chiller technical documentation.
- Design Condenser Delta T The temperature difference between the entering and leaving water through the chiller barrel when the chiller is running at full load, i.e., the entering temperature is 85°F and the leaving temperature is 95°F then the delta T would be 10. Modern high efficiency chillers are designed to run at 9.4°F delta T at 3gpm/ton.
- Design Condenser Refrigerant Approach Temperature The difference between the condenser water out temperature and the condenser leaving refrigerant temperature at design full load. This information can be found in the chiller technical documentation.
- Design Condenser Water GPM Below is a list of design GPM ratings based on the chiller design delta T.
- Entering Water Temperature: 85°F - Delta T Range: 10-20°F - Normal delta T: 10°F - 3.0 GPM/Ton @ 10°F delta T - 2.5 GPM/Ton @ 12°F delta T - 2.0 GPM/Ton @ 15°F delta T - 1.5 GPM/Ton @ 20°F delta T - 5,000 Btuh/GPM @ 10°F delta T - 6,000 Btuh/GPM @ 12° F delta T - 7,500 Btuh/GPM @ 15°F delta T - 10,000 Btuh/GPM @ 20°F delta T - ARI Condenser Fouling Factor: 0.00025 Btu/Hr.Ft2.°F
- Design Entering Condenser Water Temperature The design entering condenser water temperature is typically 85°F based on ARI standards for chillers commissioned after 1989. This information can be found in the chiller technical documentation.
- Design Evaporator Chill Water GPM Below is a list of design GPM ratings based on the chiller design delta T.
- Leaving Water Temperature: 42-46°F - 10-20°F delta T - 2.4 GPM/Ton @ 10°F delta T - 2.0 GPM/Ton @ 12°F delta T - 1.5 GPM/Ton @ 16°F delta T - 1.2 GPM/Ton @ 20°F delta T - 5,000 Btuh/GPM @ 10°F delta T - 6,000 Btuh/GPM @ 12°F delta T - 8,000 Btuh/GPM @ 16°F delta T - 10,000 Btuh/GPM @ 20°F delta T - ARI Evaporator Fouling Factor: 0.00010 Btu/Hr.Ft2.°F - Chilled Water Flow Range: Chiller Design Flow ±10% - Chiller Tube Velocity for Variable Flow Chilled Water:
- Minimum Flow: 3.0 FPS - Maximum Flow: 12.0 FPS
- Design Evaporator Delta T The temperature difference between the entering and leaving water through the chiller barrel when the chiller is running at full load, i.e., the entering temperature is 54°F and the leaving temperature is 42°F then the delta T would be 12.
- Design Evaporator Refrigerant Approach Temperature The difference between the evaporator chill water out temperature and the evaporator leaving refrigerant temperature at design full load. This information can be found in the chiller technical documentation.
- Design Full Load Design refers to full load conditions. Full load is a chiller running at 100% load capacity, 85°F ECWT, 42-46°F leaving chill water temperature and is the rating of the manufacturer.
- Design Full Load Amps The maximum amp load on the chiller. This information can be found in the chiller technical documentation.
- Design Kw/Ton The Kw used to produce one ton of cooling when the chiller is running at full load design (ex: 0.6). This information can be found in the chiller technical documentation.
- Design Specifications Manufacturer tested specification when determining design to actual operations. This includes the chiller, cooling tower, air handlers, etc. to ensure expected performance of the equipment.
- Digital Manometer Measures positive and negative air pressures in ducts, from room to room, and for taking traverses.
- Distribution Holes Holes in the hot deck of a cooling tower designed to evenly distribute the water flow over the tower fill below.
- Drift Entrained water droplets leaving the tower system. If the drift is severe, caused by missing or damaged drift eliminators, it can increase corrosion to the fan components.
- Drift Eliminator A device that removes entrained water droplets (drift) from air leaving the tower system.
- Dry Bulb The ambient outside temperature.
- ECWT Entering Condenser Water Temperature
- Emulsification The entrainment of one substance into another, i.e., oil in water or oil in refrigerant.
- Energy Balance Energy cannot be created or destroyed during heat transfer; therefore the amount of energy leaving the source must equal the amount reaching the sink.
- Entering Condenser Water Temperature Entering condenser water temperature is the temperature of water entering the condenser.
- Enthalpy The quantity of internal energy of a body plus the product of its volume and pressure.
*Erosion The group of natural processes, including weathering, dissolution, abrasion, corrosion, and transportation, by which material is worn away. *Evaporation The process a liquid goes through to change phase from a liquid to a vapor.
- Evaporator Heat exchanger where the system heat is absorbed and the refrigerant evaporates into a gas. By continually pulling refrigerant vapor out of the evaporator headspace, low pressure can be maintained causing the refrigerant to evaporate rapidly. Evaporation cools the refrigerant. This cold refrigerant produces chilled water by heat transfer. The evaporator side is commonly referred to as the closed loop system (chill water).
- Evaporator Chill Water GPM (Gallons per minute) The gallons of chill water going through the evaporator per minute.
- Evaporator Delta P The pressure drop between the suction side and the discharge side of a chiller barrel. This pressure drop is measured against known values to determine the water flow GPM through the chiller barrel. Delta P is dependant on chiller tube ID and tube length.
- Evaporator Delta T The temperature difference between the entering and leaving water through the chiller barrel. i.e., the entering temperature is 54°F and the leaving temperature is 42°F then the delta T would be 12.
- Evaporator Fouled
and/or Scaled A film or compound, which attaches to the internal tube surface, impeding heat transfer and lowering efficiency.
- Evaporator Refrigerant Approach Temperature The leaving water temperature minus the refrigerant temperature. The refrigerant temperature can be determined by locating the evaporator (suction) pressure on a pressure/temperature chart, or if the chiller control panel provides this information.
- Evaporator Leaving Refrigerant Temperature The temperature of the saturated leaving refrigerant is at prior to leaving the evaporator in the refrigerant cycle.
- Evaporator Pressure A vacuum measured in inches of Hg (mercury) for low-pressure chillers and a positive pressure (psig) for high-pressure chillers. This vacuum/pressure correlates to refrigerant temperature on a pressure/temperature chart for each refrigerant type.
- Evaporator Refrigerant Level The level of the liquid refrigerant in the evaporator barrel.
*Fan A device for producing a current of air in the cooling tower used to remove heat from the condenser tower system.
- Flow Rate The quantity of fluid in motion per a unit of time. Flow rate is expressed in mass per unit time or volume per unit time.
- Flute Allows the transfer of liquid refrigerant from the condenser back to the evaporator.
- Flute Frosting A problem associated with rapid movement of liquid refrigerant at low temperatures from the condenser to the evaporator, causing frost to form on the flute.
- Fouled Tubes Debris or substance which impedes flow or heat transfer. Fouling can be caused by trash, chip scale “flash corrosion”, microbio, etc.
- Free Oil “Free” or floating oil on top of a liquid with a higher specific gravity.
- Full Load Design Design refers to full load conditions. Full load is a chiller running at 100% load capacity, 85°F ECWT, 42-46°F leaving chill water temperature and is the rating of the manufacturer.
*Gasket Any of a wide variety of seals or packings used between matched machine parts or around pipe joints to prevent the escape of a gas or fluid.
- Gauge An instrument or device for measuring, indicating or comparing a physical characteristic, i.e., temperature or pressure.
- GPM Gallons Per Minute
- Heat When energy is added to an object or location, the motion of the molecules increases causing them to collide more frequently. The motion energy is converted into heat during the collisions. As more collisions occur more heat is released and the temperature of the object or location increases.
- Heat Index The heat index is the combination of actual outside air temperature plus the affect of relative humidity to give an apparent temperature.
- Heat Exchanger Device that provides a practical means for the working fluid to heat or cool the conditioned fluid efficiently with out the two fluids mixing.
- Heat of Rejection
(Heat of Expansion) The amount of heat rejected by the refrigerant in the condenser, which includes compressor heat.
- Heat Sink Object or location that is at a lower temperature than the heat source and receives the energy from the source.
- Heat Source Object or location that is at a higher temperature than other objects or locations.
- Heat Transfer The movement of energy as heat moving from a heat source to a heat sink.
- Heat Transfer Coefficient A proportionality constant in the heat transfer rate equation derived from the conditions of the fluid motion, the tube or fin surface geometry, and other thermodynamic properties.
- Heat Transfer Efficiency The ability of heat to transfer from one substance to another.
- Heat Transfer Fluid Any gas or liquid used by heat exchangers to transfer heat.
- Heat Transfer Rate Amount of energy that is moved from the heat source to the sink per an amount of time. Usually stated as Btu/hr in the English measurement system and Watts (Joules per second) in the Metric system.
- High Pressure Chiller A chiller that operates in a positive pressure for both the evaporator and condenser (measured in psig). Some high-pressure refrigerants include R-12, R-22, R-134a and R500.
- Hot Deck The top deck of the cooling tower where the condenser water returns to the tower prior to be cooled by evaporation, also referred to as the hot basin.
- Hot Deck Distribution Holes Holes in the hot deck that distribute the flow of returning condenser water evenly across the tower fill.
- Hot Gas Piping (Piping) A means of recirculating hot discharge refrigerant back into the evaporator. The refrigerant must pass through a pressure-reducing device (hot gas bypass valve). The purpose of hot gas bypass is to maintain a minimum gas volume flow rate through the compressor to avoid surging or stalling during low load conditions. A disadvantage is that the work of compression on the recirculated refrigerant does not generate any refrigeration effect.
- Hot Wire Anemometer Measures air velocity in grilles, filters, coils and ducts.
- IPLV – Integrated Part Load Value A single number, part-load efficiency indicator calculated using the ARI method at standard rating conditions. Introduced in ARI Standard 550-1986, the definition of IPLV was changed in ARI Standard 550/590-1998 to more closely reflect actual operating experience found in the field for a single chiller.
Kw/ton A kilowatt (Kw) is a measure of electrical energy. A ton is a measure of cooling and is defined as 12,000 BTU of cooling per hour.
- Laminar Flow Smooth undisturbed flow of a fluid.
- Latent Heat Heat given off or absorbed during phase change (condensation, evaporation, solidification, melting, or sublimation).
- Lay-up The process of winterizing a tower or condenser system when not in use.
*Legionella A bacterium of the genus legionella, especially pneumophila, that can cause Legionnaires’ disease - an acute, sometimes fatal respiratory disease caused by and characterized by severe pneumonia, headache, and a dry cough.
- Liquid Refrigerant The compressor coolant used in the refrigerant cycle of a chiller for heat transfer.
- Liquid Refrigerant Stacking This condition occurs can be caused by mechanical failure or low head pressure in the condenser and evaporator caused by low condenser water temperature.
- Liquid Piping Refrigerant piping from the condenser outlet to the evaporator inlet.
Load Amp load is compared to full load and the percentage value equals the load of the chiller. Actual amps divided by full load amps is the percentage of full load design.
- Load Swing A large or radical change in cooling load requirements, i.e., weather or building operations requirements.
- Log Mean Temperature Difference A specialized average temperature difference used to determine the heat transfer rate.
- Low Pressure Chiller A chiller that operates the evaporator in a vacuum, measured in inches of Hg (mercury). In some cases relating to entering condenser water temperature, the condenser may also operate in a vacuum. Some low-pressure refrigerants include R-11, R-113, R-114, R-123.
- Maintenance Practices An organized schedule of chiller and plant maintenance.
- Microbe An organism of microscopic or ultramicroscopic size.
- Non-Condensable Gasses (Air) Air that enters the evaporator through a vacuum leak and migrates to the condenser (in low-pressure chillers only). This affects the condenser head pressure, condenser refrigerator approach temperature and condenser heat transfer efficiency.
*NPLV – Non-standard Part Load Value A single number, part-load efficiency indicator calculated using the ARI method referenced to rating conditions other than ARI standard. The 1998 standard adopted NPLV for situations when a single chiller is not intended to operate at standard ARI rating conditions. *Oil Used as the lubricant in the compressor system to lubricate and protect bearings, shaft, etc.
- Oil Analysis Tests used to determine impurities and the ability of the oil to lubricate.
- Oil Change Interval The length of time between oil changes, determined by hours of operation, oil analysis, etc.
- Oil Entrainment Entrainment is another term for flow. This term is primarily used to reference the flow of oil through the system to the return.
- Open Loop The condenser/tower side of the chiller system, open to the atmosphere.
- Operating Conditions The values of temperature, flow rate, and pressure of the heat transfer fluids as they enter and leave the heat exchanger. Used to determine the heat transfer rate for the heat exchanger.
- Part Load Chiller load conditions below full load design. Most chillers operate at part load ~99% of the time.
- Plate Exchanger A heat exchanger used to create free cooling (not using a compressor or refrigerant to transfer heat) by running colder tower water over stainless steel plates which transfers heat between the closed loop to the open loop.
- Power Factor The ratio of actual power (Kw) to apparent power (kVA). Most centrifugal motors have a power factor between 0.87 and 0.91. Additional capacitors can be added to raise the power factor to a practical limit of 0.95. In the table below, the closer the length of the kVA line is the the kW line the more efficient the user of the energy.
- Pressure Drop Amount of reduction in the pressure of a fluid between the entering and leaving pressures. The pressure drop in a chiller is dependant upon the tube ID of the tube bundle and its length. Rough surfaces or objects that are in the flow path can cause reduced pressure.
- Pressure Gauge An instrument that measures pressure in psig, psid or psia depending on the circumstances.
- Primary Surface Area The area that contains the working heat transfer fluid. Usually the tubes of a finned/tube heat exchanger.
- Pump A device used to circulate fluid from one location to another.
- Pump Curve The design capacity of a pump’s ability to circulate fluid.
- Pump Curve Calibration A flow test to determine the capacity of a pump’s ability to circulate fluid.
- Pressure The application of force to something by something else in direct contact with it.
- Pressure Drop The reduction in pressure between a fluid entering and leaving a closed system.
- PretreatmentThe removal of oil and grease from new piping and chillers to ensure maximum heat transfer. It should also lay down a passivating film to prevent flash corrosion and in some cases, white rust.
- Pumpout System Pumpout systems consist of a storage tank large enough to hold the chillers entire refrigerant charge and a refrigerant pump/compressor to move the refrigerant from the chiller to the pumpout tank and back again. It’s primary purpose is for servicing the chiller.
- Purge Unit Removes non-condensable gasses (air) from the condenser barrel of the chiller. Required on all low-pressure chillers only.
- Quality The ratio of vapor mass to total mass of a substance at the substance's saturation temperature and pressure.
- RAT Refrigerant Approach Temperature
- Refrigerant The mechanism used by the chiller, which performs heat transfer by converting from liquid to gas and gas to liquid at various pressures and temperatures. Common refrigerants used in commercial HVAC are R-11, R-12, R-22, R-113, R-114, R-123, R-134a, R-500.
- Refrigerant Analysis Laboratory analysis of a refrigerant sample to determine contamination, typically oil or moisture.
- Refrigeration Effect The amount of heat absorbed by the refrigerant in the evaporator.
- Restricted Flow Restricted flow is caused by an obstruction (blockage) in system piping, chiller barrel or tower system.
- Retrofit A retrofit is a modification to a chiller system. For example, a new style compressor replacing an older, less efficient style or to use a different refrigerant to comply with new standards. The results can affect energy efficiency.
- Rotating Vane Anemometer Measures air velocity by use of a rotating vane or fan.
- Sacrificial Anode An anode that is made of a metal, typically zinc or magnesium, that is lower on the galvanic chart so it will be sacrificed to protect the mild steel tube sheet and end bells in the chiller from galvanic corrosion.
- Seal A seal is a tight and perfect closure (as against the passage of gas or water) or a device to prevent the passage or return of gas or air into a pipe or container.
- Secondary Surface Area The area that extends from the primary surface area into the fluid being conditioned to enhance the heat transfer.
- Sensible Heat Heat that causes a change in the temperature of an object or location.
- Separation Gasket Gasket used to separate a two or more pass chiller between the inlet and discharge of the chiller.
- Specific Heat The ratio of the quantity of heat required to raise the temperature of one pound of a substance one degree Fahrenheit to that required to raise the temperature of one pound of water one degree, Btu/lb. For the metric system, the unit of mass is kilogram and the temperature scale is Celsius.
- SRB Sulfate Reducing Bacteria. SRB can cause significant localized pitting corrosion and severe damage in the cooling tower system.
- Strainer Used to remove foreign material from the water flow. The mesh size determines the size of the material/debris being removed.
- Superheat Test A superheat test is the excess of the gas suction temperature above the gas
- saturation temperature
The purpose of the superheat is to ensure that liquid refrigerant does not enter the compressor. Typically the standard is between 10 and 20°F. A high superheat value is an indication of low refrigerant levels and low superheat value is an indication of high refrigerant levels especially when the compressor is operating at full load.
- Suction Piping Refrigerant piping from the evaporator outlet to the compressor suction inlet.
- Temperature Degree of hotness or coldness of an object or location measured on a definite scale.
- Temperature Difference Degree of change between two temperatures.
- Thermal Expansion Pressure and temperature regulation valve, located in the liquid line, which is responsive to the superheat of the vapor leaving the evaporator coil.
- Thermal Conductivity Material property indicating how easily heat travels through material. It depends on the physical structure of matter at both the molecular and atomic level as well as the state of matter, solid, liquid, or gas.
- Thermometer Measures and evaluates temperature.
- Transcritical Cooling Cooling by using the subcritical and supercritical state of the refrigerant. The critical point of a substance is the temperature and pressure where the phase changes to what is called a "supercritical fluid" which shows properties of both a liquid and a vapor at the same time. Only a substance that has a critical point near the ambient temperature can be used, making CO2 the refrigerant of choice for this process.
- Total Surface Area The sum of the primary surface area and secondary surface area.
- Tube A pipe that water flows through to transfer heat.
- Tube Bundle A group of heat exchanging tubes.
- Turbulent Flow Disturbed, chaotic flow of a fluid. The velocity at a given point varies erratically in magnitude and direction.
- Two Phase Flow Change in phase (liquid to gas, gas to liquid), due to changes in pressure or temperature, that takes place while the fluid is circulating through the heat exchanger.
- Ultrasonic Flow Meter A device that is used to measure flow through piping.
- Vacuum A space partially exhausted by artificial means (i.e., suction measured in inches of Hg in a low pressure chiller).
- Variable Frequency Drive (VFD) A chiller with a variable frequency drive has a controller that monitors the operating conditions and uses a combination of inlet guide vanes and speed control. VFDs act as a soft-starter. VFDs can offer significant energy savings at part load conditions, but they typically do not run as efficiently at full load when compared to constant speed drives.
- Vortex A mass of fluid (as a liquid) with a whirling or circular motion that tends to form a cavity or vacuum in the center of the circle and to draw toward this cavity or vacuum bodies subject to its action.
- Volts The practical meter-kilogram-second unit of electrical potential difference and electromotive force equal to the difference of potential between two points in a conducting wire carrying a constant current of one ampere when the power dissipated between these two points is equal to one watt and equivalent to the potential difference across a resistance of one ohm when one ampere is flowing through it. Typical chiller voltages are 460, 480, 2400 or 4160. This information can be found in the chiller technical documentation.
- Water Treatment Program A water treatment program provides a biocide program that minimizes microbiological growth along with excellent scale/corrosion protection.
- Wet Bulb The combination of outside air temperature and relative humidity, affecting the ability of the tower to evaporate water into the atmosphere. The higher the relative humidity, the more difficult it is to evaporate additional moisture.
- Working Fluid The heat transfer fluid that changes the temperature.
Chiller Basics
editWhat is a Chiller?
A chiller is a water-cooled air conditioning system that cools inside air, creating a more comfortable and productive environment. Chillers are also used in the manufacturing environment to provide "process" cooling to equipment in an effort to maximize productivity. With large facilities, such as commercial buildings, hospitals, universities, government facilities and theme parks, the cost of energy to generate cooling in excess of 50 tons is cost prohibitive with air-cooled units. Water-cooled chillers produce higher tonnage at lower costs per ton, creating greater energy efficiency. A typical home has 3-5 tons of cooling capacity.
How a Complete Chiller System Works
Chillers circulate chilled water to air-handlers in order to transfer heat from air to water. This water then returns to the evaporator side of the chiller where the heat is passed from the water to a liquid refrigerant (freon). The refrigerant leaves the evaporator as a cold vapor and enters the compressor where it is compressed into a hot vapor. Upon leaving the compressor, the vapor enters the condenser side of the chiller where heat is transferred from the refrigerant to the water side of the condenser where it is circulated to an open cooling tower for the final removal of heat via evaporation in the cooling tower.
What is Chiller Efficiency?
Chiller efficiency is the amount of energy (electricity) it takes to produce a "ton" of cooling. It is expressed as kw/ton. All chillers have a designed kw/ton efficiency that was established when the chiller was commissioned. Plant design, water treatment, maintenance practices, chiller age, cooling tower design, cooling load and plant operations dramatically effect chiller operating efficiency and operating costs.
Chiller Operation, Service and Maintenance
A chiller "operator" is known by several titles, including Stationary Engineer, HVAC Engineer and Service Technician. Operation and maintenance includes collecting and logging data from various gauges, controls and meters located on or near the chiller. Service contractors, who specialize in equipment repair, are contracted when major repairs or overhauls are required. There are essentially three types of maintenance performed on chillers; water chemistry, mechanical maintenance and operational procedures. Water chemistry is maintained to keep proper balance and minimize the effects of scale, corrosion and micro-biological / debris fouling. Mechanical maintenance includes proper lubrication, adequate liquid refrigerant, oil levels and pump curve tests. Operational procedures include eddy-current tests, oil analysis, calibration of gauges and meters and other various tests.
Types of chiller
editA Chiller is a machine that produces chilled water (usually mixed with ~20% glycol and corrosion inhibitors) which is used to cool and dehumidify air in commercial and industrial facilities (see air conditioning). A typical chiller is rated between 15 to 1000 tons (180,000 to 12,000,000 BTU/h or 53 to 3,500 kW) in cooling power. There are basically four different types of chillers:
1) Reciprocating,
2)centrifugal,
3) screw-driven chillers
are mechanical machines that can be powered by electric motors, steam, or gas turbines.
4) Absorption chillers are powered by a heat source (such as steam or hot water).
They have very low electrical power requirements - very rarely above 15 kW combined consumption for both the solution pump and the refrigerant pump.
Chilled water is then distributed to air handling units as a refrigerant. The air handling unit is a heat exchanger consisting basically of a fan, a filter bank, and heating/cooling coil, inlet/outlet chilled water port, and air inlet port. These air handling units provide air conditioning to the building by running the incomming warm air through the coil of chilled water, transferring the heat from the air to the chilled water, thus, cooling the air. Chillers can be
a) air-cooled
b) water-cooled.
Water-cooled chillers incorporate the use of cooling towers which improve heat rejection more efficiently at the condenser than air-cooled chillers. Industrial Chillers cool water using refrigeration cycles to provide a constant stream of coolant for manufacturing and laboratory processes. Industrial chillers use refrigeration to cool water that is then pumped through process or laboratory equipment. Industrial chillers are used in the controlled cooling of plastics during fabrication, manufacturing elements such as printer rollers, and high-heat specialized items such as MRI machines and lasers. Industrial chillers typically come as complete packaged closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion tank, no-flow shutdown, and temperature control.
Industrial Chillers cool water using refrigeration cycles to provide a constant stream of coolant for manufacturing and laboratory processes. Industrial chillers use refrigeration to cool water that is then pumped through process or laboratory equipment. Industrial chillers are used in the controlled cooling of plastics during fabrication, manufacturing elements such as printer rollers, and high-heat specialized items such as MRI machines and lasers. Industrial chillers typically come as complete packaged closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion tank, no-flow shutdown, and temperature control.
Closed loop industrial chillers recirculate a clean coolant at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments.
Open loop industrial chiller systems are also available. Open loop industrial chillers control the temperature of a liquid in an open tank or sump by constantly recirculating it. The liquid is drawn from the tank, pumped through the chiller and back to the tank.They are often used in injection and blow molding, metal working cutting oils, welding equipment, die-casting and machine tooling, chemical processing, pharmaceutical formulation, food and beverage processing, lasers, vacuum systems, X-ray diffraction, power supplies and power generation stations, analytical equipment, semiconductors, compressed air and gas cooling.
central air conditioning system
To cool down a large building, it is often better to have a central air conditioning system. It is simpler to have the refrigerant unit located at one place, and distributing the coolness using water. Chilled water is easily pumped and it is able to reach all floors in the building. The heart of the central air conditioning system is the chiller. Chillers make use of the refrigeration principles to work.
A compressor is used to compress the refrigerant gas to a higher temperature. The hot gas is then cooled by a heat exchanger. The heat from the hot gas is dissipated to the outdoors through cooling towers or fans. The hot gas, after being cooled, reverts back to a liquid state. This is the property of most refrigerants, to be liquid at normal room temperatures and pressures. This liquid is then led through a valve or orifice. The liquid becomes expanded in volume after passing through this restriction. The expansion of volume through the expansion valve or orifice brings about a cooling effect. Heat is absorbed when the liquid becomes a gas. The cooling effect is used to cool chilled water through a heat exchanger. The chilled water system is then pumped and distributed to all the air handling units at various floors in the building. The air handling units contain fans for moving air through cooling coils. The indoor air is thus cooled.
The flow of the heat in central air conditioning system can be summarized as follows:
Heat is transferred from the air in the rooms to chilled water at the air handling units. The chilled water is pumped through the chiller and the heat is transferred to the refrigerant. The refrigerant is cooled by cooling water circulating in the condenser of the chiller. The heated cooling water is passed through cooling towers where the heat is dissipated to the atmosphere by fans.
Compressor ------ Condensor ----- Cooling tower ---- Evaporator ---- Compressor
Types of Chillers
Chillers are a general term for air conditioning units using chilled water as a distributing agent. They are named according to the type of compressors they use.
Centrifugal chillers use centrifugal impellers and high rotational speeds to work.
Reciprocating chillers contain pistons, crankshafts, suction valves and discharge valves.
Screw chillers use screw shafts to compress the refrigerant gas.
Different manufacturers produce their own designs based on these basic ideas of compression. Some manufacturer design for multistage compression, some have enclosed electrical motors in the refrigerant circuit, while others have external motors. Many of the control systems are designed to suit the different manufacturers. The settings of controls and machine design also depend on the refrigerant they use. There are also different configurations for air or water cooled condensers.
The lubrication oil for chillers is special oil that is compatible and able to mix freely with the refrigerant. All manufacturers have their own arrangements to suit their own designs, with oil heaters, oil bath, oil pumps, and others.
Centrifugal Chiller
Large sized chillers have centrifugal fans to compress the refrigerant gas. As with any high-speed centrifugal fans, these chillers are susceptible to surging if the system is not matched properly. Whenever there is a sudden change in the heat loads or speeds, there is a possibility of surging. Many manufacturers design their machines to cater for these sudden changes. For normal usage, there is almost no problem in this area. Normally the condensers are water cooled, and they work in conjunction with cooling towers.
Reciprocating Chiller
The motors of reciprocating chillers are usually totally enclosed inside the refrigerant circuit. The pistons are made small in size. Because of the reciprocating movements of the several pistons (6 to 8 pieces), these chillers are usually noisy. They commonly use R-22 refrigerant. Very often the condensers are air-cooled.
Screw Chiller
Screw chillers are usually totally enclosed. They use R-22 refrigerant.
Colour codes in Plumbing
editWATER TREATMENT PLANT COLOR CODING
TYPE OF PIPE USE OF PIPE COLOR OF PIPE
*Water Lines: Raw water Olive Green Settled or clarified water Aqua Finished or potable water Dark Blue
*Chemical Lines: Alum or primary coagulant Orange Ammonia White Carbon slurry Black Caustic Yellow w/ green band Chlorine gas or solution Yellow Fluoride Light blue w/ red band Lime slurry Light green Ozone Yellow w/ orange band Phosphate compounds Light green w/ red band Polymers or coagulant aids Orange w/ green band Potassium permanganate Violet Soda ash Light green w/ orange band Sulfuric Acid Yellow w/ red band Sulfur Dioxide Light green w/ yellow band
*Waste Lines: Backwash waste Light Brown Sludge Dark Brown Sewer (sanitary or other) Dark Gray *Other Lines: Compressed Air Dark Green Gas Red Other Pipes Light Gray
Wastewater Treatment Plant Color Coding
TYPE OF PIPE USE OF PIPE COLOR OF PIPE
*Sludge Lines: Raw Sludge Brown w/ black bands Sludge recirculation or suction Brown w/ yellow bands Sludge drw off Brown w/ orange bands Sludge recirculation discharge Brown
*Gas Lines: Sludge Gas Orange (or Red) Natural Gas Orange (or Red) w/ Black bands
*Water Lines: Nonpotable Water Blue w/ black bands Potable Water Blue
*Other Lines: Chlorine Yellow Sulfur Dioxide Yellow w/ Red bands Sewage (wastewater) Gray Compressed Air Green
It is also suggested that the direction of flow and name of the contents be noted on all lines...
SWIMMING POOL DETAILS
edit1. Preliminaries 2. Designing pool and surroundings 3. Pipe work designing 4. Pool Equipments 5. Accessories 6. Cleaning the area 7. Construction sequence 8. Out sourcing 9. Surroundings
PRELIMINARIES • Pool Usage – Why we are Building the Pool - This needs careful consideration as the wrong style or size pool could be regreted 10 years down the track. Always remember that the children who are now 4 or 5 will be 14 or 15 in ten years & may not want to use the pool & may not be around to look after it. They may want it deep now but when you the parents get older, you will want the pool for exersice, relaxation, & easy maintainance. A nice 1.2M flat bottom is much easier & more useful. • Life Changes in Owning a Pool or Spa.
Consider the work involved in maintaining the pool. (only about 2 hours a week but who will do it). You will need to be much more aware of who is in your yard, even if the pool is fenced. You will possibly have a lot more of your children's friends around, do you want to handle that. Who will look after the pool when you go on holidays?
• Regulations – There are now many regulations regarding owing a pool, these include, Building regulations, Fencing regulations, Insurance Regulations, you will need to check these with your local council & if need be, obtain a copy of the Australian Standards for these areas. • Position/Location – A pool close to the house is easy to watch over & nice to roll out the door into in the morning but it is very noise when there are 10 children clowning around in it. A pool set out in the garden needs to be able to be seen some how even if it is fenced to give some control of usage but can make it better for entertaining to open up the yard. • Type of Pool –
Do you want a concrete, fiberglass, Vinyl Liner pool, It all depends a lot on Budget but it can also be controlled by the ground you are building in or on & also by the relative value of the pool to the value of the house.
DESIGNING POOL & SURROUNDS
POOL DESIGN: The design of the pool is influenced by a number of items: 1. The Land in which you wish to construct the pool, 2. Also if the pool is set out in the yard a freeform style design possibly with a more natural set of finishers may blend in well, while if the pool is close to the house it may need to have more formal lines to match the house lines. 3. The Type of People who will predominately be using the pool. If you have a large family then some deeper 1.5-2.0M depth could be good for playing games in, but if you consider its use for 20 years when the parents are the only ones using it & they are older then possibly a 1.2-1.4M overall depth would be better. 4. The Possibility of Enclosing the Pool, due to weather etc. 5. The Budget for the Pool.
POOL FINISHESkl?: INTERNAL
TILES:
These are the most expensive but do give the longest lasting finish if applied correctly & the correct tiles chosen for the paticular application. There are now a number of different types of material for tiles used in pools:
Ceramic Tiles
Either 150x150mm or 100x100mm 0r 75x75mm plain colour or pattened, or Moasic tiles on sheets in plain or pattened colours,
Glass Moasic
Tiles which can provide a very expensive look to the pool.
Plastik: Tiles
These are a plastic extruded tile which is laid as tiles were many years ago where in the adhesive (white cement or colored CTF) is placed on the back of the tile & then the tile set in place, the adhesive also acts as the grout.
PEBBLE
The use of small evenly colored pebble set in white or grey cement has become a very much used system in the last 10 years. Its predominance has been brought about by the want for the "Natural Look" pool. The use of pebble is much less costly but the upkeep is greater because of its uneven textured surface.
MARBLESHEEN - MARCITE
A Mixture of marble dust & white cement, the system has been used for many years to provide a long term medium cost attractive finish. The finish is a beautiful pristine white which gives bright blue looking water.
PLASTER & PAINT
Plastering- Rendering the interior surface of a pool to a beautiful smooth finish & then applying a number of coats of either, Epoxy of Chlorinated Rubber Paint , has been the choose. The system is very efficient but does not last as long as Marble sheen or Pebbling.
FIBREGLASS AS AN INTERNAL FINISH
Many pools are first plastered- Rendered & the four or five layers of fiberglass mat of varying thicknesses are laid over the plaster to give a smooth impervious finish.
VINYL AS AN INTERNAL FINISH
The manufacturers claim that the Vinyl stands up better over a long period of time. The Vinyl comes in many colors & is quite cost effective. It can be used as a finish on a concrete constructed pool or on a specially built frame of metal or timber.
SURROUND EDGE
• Style - There are various types of edges which can be incorporated with a pool
• The standard 300mm wide coping with a finish of some type which is different to the pool internal finish & different to the surrounding area. This edge usually sits up 100mm above the surrounding walk way to prevent rubbish blowing into the pool. The same 300 but matching the surround paving. The edge can finish flush with the inside if the pool or can lip over to help prevent water loss. You can incorporate the surround right over the edge of the pool so that there is no break in the finish on the horizontal plane, this requires that you leave the pool wall concrete about 75mm lower than you may normally do so. This can help to make a small area around the pool look much bigger. • Material- You can use Brick. Paving stones, Natural rock, Pebble or a nonskid tile on the 300mm wide type edge. You can use the same finish material or texture as the surrounding paths either on a raised or flat 300mm edge but always leave an expansion gap of 10mm between the pool shell & the surround. You can pour a deck right over the edge of the pool so that there is no joint showing on the horizontal, the main consideration for this is to look like a bigger area & have cleaner lines. This inside edge can then be moulded to a number of shapes using easily installed low cost foam moulds. • Considerations - Slipperiness, always test any surface which you may consider using before applying it or ask the supplier to refer you to a current pool owner where you can test it. Roughness - If the finish is to rough, then you could find that the children who stay in the pool a long time & their feet go soft could, find the finish very painful to walk on. Pourous - If the finish is to pourous,then water & dust could soak into it and activate the growth of algae, make sure that the finish seals well.
GENERAL SURROUND CONSIDERATIONS:
• The Area: - Many council bylaws will no longer allow you to have any recreational area inside the pool fence, EG Bar-b-que or tables 7 chairs. If this is so then you only need 600mm to 1000mm of width of paving on two or more sides of the pool for access, & the rest of your entertainment area can be outside the pool area. If the council does allow you to use more area inside the pool fence, consider how much you will need for tables & chairs & that it needs to be level for these & still needs to allow movement around the chairs. Also consider the drainage of the area by always allowing a slight fall away from the pool to remove rain water to a drainage gutter or pipe. • The Pool Fence: You will need to check your local council regulations regarding pool fencing to see if you have to have a dedicated pool surround fence or a pool area fencing or the backyard fenced. Add to this your own personal consideration as to the safety of childern in the area.
• Trees & Gardens: You must consider the trees & gardens you currently have & those that you propose to plant. It is nice to have the pool in a "Natural Bush Setting" with trees over the top & garden falling into the water in various areas, but that will cause a dramatic increase in maintenance unless the trees are evergreen & even then they need to be the type that does not loose its leaves or drop pollen or flowers.
Hydraulics & Filtration.
o Length - The Length of the pool will depend upon what you are looking at using the pool for, if you wish to do laps then make the pool as long as you can fit in the yard & also if it is an irregular shape pool, then you will have an average length as you may not be able to measure each section of the length exactly.
o Width - The width will also be related to the use of the pool both now & in the future, if it is more for recreation, then in most cases it will be a wider pool but if it is more for exercise, it will be a narrower pool. If children are using it, they tend to want to dive in from the sides, so you need to give a reasonable width say 3-5metres or 10 - 15 Ft to give a safe room for them to enter the water.
o Depth - Two main depths to know, the shallow end (usually the entry end & the deep point. (the deep point should never be at the end but should always be equal distance from the two side & deep end walls) The water depth is 75-150mm less than the construction depth. o Surface Area - average length x the average width
EG: 10M (33Ft) long by 5.5M (18Ft) wide = 55 Sq.Metres (594 Sq.Ft)
o Volume - Take the average depth & dividing by 2. & multiply this by the
SURFACE AREA Average depth X Surface area
EG: (1.050M (3'6") + 2.0M (6'7"))/2 x 55 (594) =83.87 CUBIC METRES or (3029 Cub Ft or 21000 USG.
In Pool Equipment
Skimmer Boxes
- Every pool needs a method by which the water leaves to be sent to the pump & filter. In most cases this is done through a Skimmer Box which is mounted in the side of the pool with its mouth centered on water level. (usually 100-150mm (4-6") below the top of the pool). The skimmer usually has a 50mm (2") connection to go to the Pump & and another 40mm (1.5") connection to go to the drain in the deepest point of the pool. The skimmer should be located such that normal prevailing winds blow debris on the water's surface into the skimmer. "It can be at either the deep or shallow end of the pool it does not have to be at the deep end." Normally one skimmer box will handle up to 60SqM (616 Sq.Ft) of pool surface area. (after that use two skimmers) or 250 litres/minute (62.5 USG/Min)of pool water. Main Drain The main drain is located at the deepest point of the pool & incorporates: 1. Connection to the skimmer box for drawing water from the base of the pool A Hydrostatic Valve in its base which is connected to an open tube below the pool floor. This allows any excess water pressure out side the pool to be released if the pool is emptied at any time. The valve is one way & won’t let water leak from the pool. (Unless it is fitted incorrectly or has rubbish in it or is deteriorated. Return Eyeballs - The eyeballs are fittings which help control the direction of the water returning to the pool. There should always be at least two eyeballs & some times more. Work on the equation "one eyeball for each 75 litre/minute (18.75 USG/Min) the pump puts out." Set the eyeballs to work in a circulating pattern to drive the debris to the skimmer box. Set the Eyeballs at least 300mm (1.0') below the surface of the water & point then down towards the floor, not up to the surface Pump Selection Check the following: To work out the size of pool pump you require divide your pool volume in litres by 4 or (gallons by 4)(the number of hours to pump all the water in your pool) & then divide by 60 (the number of minutes in the hour) that your pump will be required to pump. EG if the volume is 60 Cubic Metres or 60000 litres 60000/4 = 15000/60 = 250 this is the minimum number of litres a minute Compare flow rates for pumps against a set pressure(HEAD) say 12 Metres or 120 kPa or 16 PSI, ask the sales person for the figures for each pump at that head, are you still getting the 250 l/min. or 62.6 g/m. If not then you need to go up one size in pump or look at a different pump. Pumps come in different sizes; the 250 l/m (62.6gpm) will need about a 750-1000 Watt or 1.0-1.25 HP Pump, 350 l/m or 87.5 gpm would need a 1200-1500 Watt or 1.5-2.0HP pump. It is a good idea to put the pump & filter & other equipment in a nice garden shed or garage or basement, the equipment will last years longer for the cost of a few metres of pipe & a few fittings. Filter Selection - Now that you know the flow rate of your pump, you can begin to select a filter for your pool. There are basically three choices.
SAND
Sand filters are predominant, not necessarily because they are the best but because they are the easiest to look after. They consist of a tank with a specially screened sand inside & a multi port valve which allows you to control the water flow through the tank. The valve has a FILTER cycle which allows the dirty pool water to enter the top of the tank & pass through the sand, leaving behind the dirt & then the water passes back through the valve & back to the eyeballs in the pool. The good thing about the sand filters is that they are easy to operate, they have a midlevel capital cost & a relitavely low operating cost. Select a sand filter by picking one that has a maximum flow rate at least 25% above the pump flow rate. o 3.4.2 DIATOMACEOUS EARTH The DE filter consists of a tank with cloth pads inside & a multiport valve which allows you to control the flow of water through the filter tank & pads. The DE powder is added to the skimmer box & flows through to coat the cloth pads in the tank. (THE PADS ARE NOT THE FILTER, THE POWDER IS). The DE collects the dirt from the water & when it has collected all it can hold, the earth & dirt combined are backwashed to waste, after which new DE powder is added. Although DE filters are a little more work when cleaning is required, if sized correctly & operated correctly they will run a lot longer between cleans than a sand filter Always pick a DE filter that will operate at at least 25% higher flow rate than that calculated for your pool. Always observe backwash line sizing recommendations. o 3.4.3 CARTRIDGE : - Cartridge filters can be very good if you use enough area, other wise you will spend a lot of time cleaning them, they are initially cheaper than the other options but a little more work & have a higher operating cost than sand filters. Select your cartridge filter by selecting one or more equal to 30% of the surface area of you pool. Eg if you have 50SqM (550 SqFt)surface area then get a 15 Sqm or (155 SqFt)of cartridge filter. You can size the filters up to 50% above the flow rate of your pump as the Cartridge filters are not dependent upon the pump volume for cleaning as the other filters are The only down side with a cartridge filter is that you have to physically take it out & wash it by hand using a high pressure hose & at regular intivals you will need to soak it in a cartridge cleaner solution to remove body fats & chemical build ups.
3.5 Pipework Selection
3.5.1 Pipe Type - It is normal to use UPVC pressure pipe not Sewer or Waste pipe for swimming pool applications. The use of waste pipe can cause premiture failure both above & below ground level. It is also preferable to use Class 12 pipe not Class 9 as it has greater mechanical strength in case you hit in the future as you are digging the garden. o 3.5.2 Pipe Size - The size or diameter of the pipe is related to how much water you want to pump through it & how far you want to pump the water. As a rule of thumb, you can say if the pump is < 600 Watts (3/4 HP) use 40mm (1.5") PVC Pressure pipe & fittings, > 600 Watts (3/4 HP) then use 50mm (2") PVC pressure pipe. 3.5.3 Horizontal Position- You will have to have the pump at least 3.0M from the waters edge unless there is a solid wall between or your local wiring regulations. You may take the pump as far as you like but if you go over 10M then you will have to increase your pipe size especially on the suction side. o 3.5.4 Vertical Position- You can have the pump any where between 2.0M below the water surface to about 500mm above the water surface with out any real problems. If you are below the surface, then you will need to install a valve in the suction line infront of the pump & a check valve in the line leaving the filter & returning to the pool. o If the pump has to be more than 500mm or 20" above the water level, then you will need to install a check (non return valve) in the suction line as close to the skimmer as possible. This check valve must have flanges or unions each side of it to allow it to be disconnected for cleaning. o 3.5.5 Pipe Installation - All pipe work except for the last few hundred mm or 8" should be level & below water level. If you run your suction line above water level on the horizontal then you will have problems with priming the pump & the pumps seal could burn. o 3.5.6 Joints - All joints must be glued correctly in accordance with the pipe & fitting manufacturers recommendations. Always make sure that the joints are square & all the way in. o 3.5.8 Backwash Lines:- The length & size of these are critical, never make a line any longer than absolutely necessary. If you are using a 600Watt (3/4 HP) pump the maximum is 6.0M or 20' on the horizontal in 40mm or 1.5" pipe, after that go to 50mm or 2" pipe. If using a pump larger than 600 Watts (3/4 HP), the use 50mm or 2" pipe all the way for up to 12 M or 40' horizontally, if you need to go furthur than that then use 80mm SWV PVC or 3" sewer or stormwater pipe & fittings.
3.6 Swimming Pool Accessories:
• 3.6.1 Manual Cleaning Equipment There are basic components which are necessary for the cleaning of a pool as follows: VACUUM HEAD: This is a plate which has rollers or brushers on its underside & which move across the floor of the pool & allow the water being drawn through the plate to suck the dirt from the floor. The vacuum head should never be lifted above the water while it is connected to the system as you will fill the pump with air. VACUUM HOSE: This hose connects from the vacuum head to the skimmer box or a vacuum connection fitting on the side of the pool. The hose allows the pumps suction to be directed to the floor of the pool to suck up the dirt. The vacuum hose is a delicate piece of equipment & should never be left out in the sun or on the grass for the children to walk on or the dog to chew on. VACUUM PLATE: If the vacuum hose connects to the skimmer box, then there is usually a vacuum plate also provided which sits above the basket in the skimmer box & allows you to seal the pump suction from the normal skimmer mouth & from the bottom drain so it is solely directed to the vacuum head during vacuuming. TELESCOPIC HANDLE: The telescopic handle is an extendable device which connects to the vacuum head & allows you to control the movement of the vacuum head over the floor of the pool. LEAF SCOOP: This also attaches to the telescopic handle & allows you to remove leaves from the pool surface & also those from the bottom which may otherwise block the vacuum head or hose. POOL BROOM: This devise attaches to the telescopic handle & allows you to brush the walls & any stubbon stains on the floor prior to vacuuming. • 3.6.2 Automatic Cleaning Equipment. These come basically in three types: o SUCTION: These units connect to the skimmer box in the same way as the vacuum hose & move about the bottom of the pool under motion created by the water being drawn through them. They suck the dirt & debri from the floor & walls of the pool & place it in the skimmer box or the filter. o PRESSURE: This style uses water pressure from the filter pump or from an auxillary pump to drive it around the floor of the pool. It normally has flailing arms or hoses which stir up the light dirt & the heavy & larger debri is drawn in to a basket atop the unit. o ELECTRIC: These units are a self contained motive power, pump, filter, unit which is driven by low voltage power around the floor of the pool. o These types of cleaners have their advantages as they take the major cleaning responsibility from your weekly chores. Which one is for your pool is always a hard question but a lot of times it comes to price & also to the shape of your pool, some types of cleaners dont work well in square corner pools & some get caught in pools with alcoves, always ask the sales rep if they have a demo unit which you can try for a few days before making a decision.
• 3.6.3 Under Water Lights Pool Lights can make a pool the center piece spectical of your yard at night, but they can some times be a problem for no apparent reasons. Points to consider: o COST: You will always need to consider not only the cost of the light & its associated transformer as most are 24V or 32V but also the cost of installation & the conduits to the pool & the switching for the lights, (manual or time clock). o NUMBER: There are world standards for lighting for commercial swimming pools & many times these are applied to domestic pools. Pools lit to this standard are expensive & so bright as to look out of place in most situations. Normally one light per 40SqM or 420SqF of surface area. You can always switch them independently or set them on a dimmer. o POSITION: Always set the lights so that they shine away from the main seating or standing area around the pool & especially away from the house. As the light exits the water it can slightly change angle & shine in to your eyes. o COLOR: Most manufacturers supply colored clip on lenses for pool lights, these can be effective but remember that they do reduce the light output dramatically. If you want to use them all the time put in more lights initially.
• 3.6.4 Chemical Feeders. There are anumber of different types of feeders feeding various products & they fall in to the following catagorys: o LIQUID PUMPS: These units are either a diarapham pump or a tube type pump & they inject liquid chlorine or a mixture of water mixed with various powder chlorines or bromines. These pumps can be manually or timeclock controlled & can also be level sensor controlled to maintain a specific PPM of chlorine. o ERROISION FEEDERS: These units are a cylinder filled with tablets of granulated or stabilized chlorine or bromine tablets or sticks & a small proportion of the filtered water passes through them. The water errodes the tablets dependent upon volume of both water & tablets & injects the resultant solution in to the circulation system. o SALT CHLORINE CONVERTERS: These systems rely upon a level of common salt (approx 3500-7000ppm) being maintained in the pool water. There is an electrolysis cell in the circulation system through which an electric current passes. The current converts the Sodium Chloride (common salt) in to a low concentration Sodium Hypochlorite (liquid chlorine) in the cell. o CHLORINE GENERATORS: These units hold a supply of common salt in a container & pass a small amount of pool water through the container, at the same time passing an electric current through the salt solution in the container. Chlorine gas is produced which is mixed with the pool water to form liquid chlorine. o IONIC STERILIZERS: These units are madeup of silver/copper electrodes & a power unit which passes current through the electrodes. The electrodes are installed in a container in the circulation system & as a current is passed through the electrodes, they breakdown & produce silver & copper electrons in the water. The silver tend to destory bacteria & thje copper tend to destory algae spore. The units normally have a controlable power input so the level of electrons in the water can be increased or decreased. These systems always need to have chlorine or another oxidizer added to break down dead organic matter. o OZONE GENERATORS:Ozone is a gas whith a very short life span & is therefore a very effective oxidizing agent. Many companies supply ozone generators which make a very very low concentration of ozone by passing air around an ultraviolet lamp. This converts the oxygen to ozone, the resultant gas is mixed with the pool or more likely spa water to break down organic matter in the water. The water will always need a chlorine or bromine or other type of oxidizing agent to carry out total breakdown of organic matter. Ozone is produced for larger pools using a corona discharge system which has a much greater expence than the ultraviolet light system. All of these systems work to various levels of efficency but the most dominant requirement is maintenance to keep components clean.
• 3.6.5 Time Clocks Time clocks can make the difference between owning a pool & a pool owning you. Time clocks can be used to maintain the following: o FILTER PUMP: This can be operated by time clock on a daily or two or three times daily basis to suit the pool usage & heating & chemical teatment requirements. o CLEANING PUMP: If you have a pressure type cleaner or an electric fully enclosed type pool cleaner, these can be set to operate in conjunction with the filter pump or off set from the filter pump as required. o LIGHTS: The pool lights can be set to operate every night at a preset time or every Friday & Saturday night for effect with a manual overide for use as needed.
• 3.6.6 Water Level Controllers Water level controllers can be broken into two main catagories. OVERFLOWS: In areas where you have a high rain fall it can be very benifical to have an overflow pipe set about 25mm or 1" above the center line of the skimmer box so that when it rains day after day, the less dense rain water flows off the top & down the drain & does not continually dilute the chemicals in the pool water. MAKEUP UNITS; These are of various types but they monitor the water level in the pool & add water as the level drops through usage, splash, evaporation or backwashing. They can be very benifical in hotter areas & where you may spend time working away from home & not be there daily in the middle of summer to keep a check on the water level.
3.7 Pool Heating
3.7.1 Gas o This is the most common type of pool water heating where control of heating & quick heat up times are required. Some common items to consider with gas heating are: SIZING: Most manufacturers produce a graph which shows the volume of your pool & the surface area & the origional low temperature & the amount you want to rais the temperature & in what time. They cross reference these to come up with a size. TIME: When it comes to a pool, it requires avery large heater to raise the temperature quickly, so you shoul really consider why you might need to raise the temperature in less than 24 hours by a set amount, combined with a bubble type cover it is some times cheaper to maintain a pool at a temperature with a smaller heater than to continually reheat it with alarger heater. especially if you have used polystryene 25-50mm (1"-2") thick between the concrete & the dirt when building your pool. CONNECTION: When the heater is connected to the pool circulation system you should consider the following: DIRECT/BI-PASS: Most heaters only run 40mm (1.5") pipework so if your main return to pool is a 50mm (2") return & you are pumping more than 250-300l/min (62.5-80 USG/min) then it is better to install two 50mm (2") tees with a 40mm (1.5") ball valve between them & connect the branches of the tees to the 40mm (1.5") heater connections. You can then shut back the 40mm valve to produce the required flow across the heater, whilst still keeping up the required total flow. POSITION: The heater should be set with its pipes such that it can never be drained of water when the pump shuts down. This is especially true when the heater is above water level. HEAT SINKS: At the inlet & outlet connection points of the heater there must be copper or stainless pipes which rise higher than the top of the heater prior to turning back down to the floor. This causes a heat trap to be created at the highest point when the pump shuts down & stops the adjacent PVC pipe from becoming hot & collapsing. CHEMICALS: It is preferable to inject the chemicals after the heater so that there is never a consentration of chemicals within the heater when the filter pump shuts down. The only down side of this is that the hot water some times crystalizes the liquid chlorine when it is being injected & the injector has to be cleaned reguarly.
3.7.2 Electric Electric heating is generally only used in spas where heaters from 1.8kW to 6.0 KW are normal sizings. Thet can go as high as 36-48Kw for commercial spas. This type of heating is used where off peak rates can be obtained. The small heaters on spas, are very good if the spa is left to operate 24hours a day on a constant heat. Electric heaters are reasonably echonomical to operate & easy to control. Electric heating of pools can become echonomical with the use of Heat Pumps which have about a 3-1 heat ratio to power input, operated on off peak rates they can be very cheap to run, their only draw back is capital cost, they are best suited to pools which are kept heated constantly. o 3.7.3 Solar o The use of solar heating on swimming pools provides from a minimal to a substancial heat input dependent upon several factors. AREA: The greater the area of solar collector the greater the absorbtion of heat & the more help you will get with the heating. There is a point where you will not get much longer swimming time irrespective of how much extra collector you put on. Generally if you can afford & have the space for an area equal to the surface area of the pool, you are doing well. DIRECTION: The more north facing roof area you can use for the solar collectors the more efficent they will be in absorbing the heat. OPERATION: If the system is automatically controlled to pump water through the solar at all times that there is sufficent heat available then the better heat gain you will achieve. WIND PROTECTION: If you can protect the collectors from the wind especially in Fall (Autumn) & Spring. This can be achieved by covering the collectors with a clear plastic sheet or similar to stop wind chill. COVER THE POOL: If you are spending daytime collecting the heat but dont cover the pool, you will loose the heat overnight as the air temperature drops. It is far more efficent to have a lightweight solar cover to put over the pool at night to retain the accumulated heat.
o 3.7.4 Combinations o Many people combine gas & solar systems to allow them to be able to swim all year round or later in the Fall & eariler in the Spring. This can be done especially with indoor pools, but it needs to be set up correctly PRIMARY/SECONDARY: You will need to decide which is to be your primary heat & which is your secondary heat. SOLAR PRIMARY/GAS SECONDARY: you will need to connect your solar to the circulation system after the heater & set the gas heater thermostat to a lower temperature than the solar. This way the solar will keep the temperature up but if it is insufficent & the pool temperature drops another degree, the gas will cut in. GAS PRIMARY/SOLAR SECONDARY: You will need to connect the solar across the gas heater. The feed to the solar pump should come from between the filter & the heater & the return from the solar should connect after the heater & after a non return valve. This way the gas will heat the water until there is enough solar & when the solar pump cuts in, it can be made to cut out the gas electronically or by reducting pressure on the gas pressure switch, it will cut out the gas heater, while the solar is operating.
3.8 Allowing for Electrical Connection • - When building the pool or having one built always consider the cost of electrical wiring to the pump within the budget before commencing, it can add on hundreds of dollars if the switch board is on the other side of the house. o This also goes for the wiring from the light transformers to the underwater lights. o The lights have to each be wired in a seperate conduit o The pump & any other 240V or 110V electrical connections need to be at least 3.0M from the pool unless protected by a building or wall, see AS3000 regulations. o Consider using a time clock on the pool pump so it operates automatically each day. o Consider using a time clock on the underwater lights so they operate for a few hours each night, they will last longer that way. o Preferably operate the pool equipment from a seperate circuit breaker on your switch board. 3.9 Allowing for Waste & Makeup Water • - Consider the following: o What are the local regulations for the backwash water from your pool filter, some require it to go to sewer & some to stormwater. Some will not allow it to go to stormwater if it contains DE. Some require you to pump the backwash water to a holding tank & settle out the solids before disposing of it. o Make up water for your pool will normally come from a close handy tap & hose, so make sure you have one in the pool area, you could also consider installing an electric automatic levelling devise.
0 PREPARING THE POOL AREA
• 4.1 Selecting the Area o When you prepare to select the area in which the pool is to be constructed, you must conside the following points: o Can the pool be seen from the Kitchen & or the Family room, irrespective of what fences or other safety devices you have around the pool, it should always be located where it can be seen by an adult whilst children are using it. o Is the access to the pool convienent from the Family room or deck area or varendah, you don't want to be walking around the back of the house to the pool all the time. Also you don't want the children to have to trapse all through the house in their wet swimwear to go to the toilet or shower. o Is the area one in which the pool will get the most sunshine & the lease leaves from overhanging trees. o Will noise from the pool become offencive to the neighbours & cause problems in the future. o Will the pool fit in aesthetically with the rest of the property. • 4.2 Picking the Level Area Point o If you have a sloping block of land, you will need to pick a point which will be the top level of the pool. This point could be at the deep end, centre or shallow end of the pool. If you pick the deep end then you may find that a lot of the pool is below the natural ground level & you have to build retaining walls. If you pick the shallow end than you may find that a lot of the pool is above the natural ground & you will have to do a lot of backfilling to make a level path or you may want to create a sloping walk way around the deep end of the pool. Normally it is easier to pick the centre of the pool & this way you have approx half of the pool which may need a retaining wall to stop the garden running into the pool & the other half will have to be built up using the dirt dug from the other end. It is not easy at times to get an idea of how the pool will be looking untill the area in which it is to be constructed is leveled & then the pool marked out using flourecent paint on the level ground. • 4.3 Checking for Utilities Always contact the Water, Gas, Electricity, & Telephone companies prior to any digging to make sure that there are no utility pipes or cables in the area where you wish to build the pool. You may find there are utilities there and you will have to make the decision to either move the pool position or to move the utilities. • 4.4 Allowing for Drainage When you build the pool on a sloping block & even on a reasonably level block, you will need to make allowance for drainage of rain & splash water from around the pool area. You will need to be very careful to drain water from the high side of the pool, where you may have built a retaining wall or there may be a natural rock wall. You want to provide specfic drainage to remove water from these areas. Also make sure to allow for drainage in the area between the pool & the house, you dont want lawn or even concrete in that area to be continually wet. • 4.5 Access for Removal of Spoil Many time with building blocks gettting smaller & smaller, it is getting harder to have access to remove the soil dug from the pool hole. If you are in a tight situation then you may have to use a bobcat or very small excavator to dig the hole & you may need to use a conveyor belt system to transport the dirt to the street for loading on to a truck. • 4.6 Reuse of Spoil As I have said eariler, dont leave the dirt or soil or rock from the pool dig on site unless it is being used for fill. (See Photo) If you are using it for fill then try to carry out the fill & compaction at the same time as the dig so that you do not get mounds of dirt in the way of your work. Always place the fill dirt in 150mm layers & then compact, then another 150mm & then compact again until the desired level is reached. You may have to store store some fill for backfilling close to the pool wall later but any other fill should be placed at digging time.
5.0 CONSTRUCTION SEQUENCE
The following instructions are a brief outline & it is preferable if the user has some knowledge of building prior to starting on a project such as a swimming pool. These notes are provide to allow persons to have some knowledge of what a contractor or sub contractor should be doing while building a pool.
• 5.1 LAYOUT - POSITION Considering the points in 1.4 above, the whole area in which the pool is to be built should be marked out so that you have a good idea of the total area you will be using. Normally I do this with some cans of flurocent paint, Light blue for the basic shape of the pool, brown for the surround area, red for extended paving, & green for new pr moved garden beds. This can be easily seen for a distance when you stand back to get a distance perspective or stand inside & look out the window to see how the end result will look. Once you are happy with the layout of the area then confirm the position of the pool & mark its outline (150mm outside the finished internal dimentions) for a normal concrete construction. This is the line which the digger will dig to. Pick your datum point (see 2.1.2) & decide the relivance this has to the top level of the pool. As you will need to refer back to this point all through the construction. Make it a point which will not get disturbed & which can be seen from any point in the pool construction area.
• 5.2 EXCAVATION
DO NOT LEAVE THE EARTH DUG FROM THE POOL ON SITE Unless there is more than adiquate room or only if there is a specific need for leveling the yard etc. In most cases if you leave the earth in the yard, it will get in the way of the digger & it will make a mess as well as making it very hard to keep the worksite clean. If the earth is used for fill on another part of the land, then in most cases it must be spread 150mm thick & then compacted & then another 150mm & then compaction, up to the required level. This should be done as soon as it is excavated. If you dig a normal 9.5M x 4.5M pool, you can get upto 100 CubM of earth out of the hole. Where possible use the biggest machine possible, a good large machine, especially an excavator can move the earth much more efficently than a small machine costing less per hour but more over all. If you use a large machine make sure that there are enough trucks to keep up with it. The machine is costing you money while it is sitting idle waiting for a truck to load. Make sure to check of underground utilities prior to digging. Make sure that you have identified the level that the top of the pool will finish at so that you can use this as a fixed point from which to check dig depths. You will need a dumpy level or water level to be able to check the depth of the excavation at various points along the floor. Where possible try to dig from the deepest point to the shallowest. it easier for the excavator operator. Make sure that the markout for the shape of the pool is 150mm (6") outside the finished internal line of the pool. (Less if using Fibrecrete & more if the engineer asks for thicker walls) Make sure that the excavator operator does not dig back past the lines as it will cost you more concrete to bring the internal wall face to its correct lines. Beware of rock or underground water seepage below ground level, both could increase the cost of the excavation. If you strike water seepage, it can cost you for dewatering for not only the dig time but possibly through out the construction or at least untill the concrete shell is complete. Always try to have the excavator trim as close to the perfect line as possible as he can carry out a lot of work much quicker than it being done by hand. (see photo) Remember that you need to dig the floor to a depth to allow for at least 75mm of gravel underdrain & 150mm of concrete floor. You can let the walls come in slightly as they go down, about 50mm for each 1000mm in depth. Remember the deepest point should be equal distance from the two side walls & the deepend wall. The walls at the deepend should be straight down for 1500mm then curve into the deepest point see accompanying typical drawings. Wall Drawing Dig out area for skimmer box & dig pit 450mm x 450mm x 450mm at the deepest point for the hydrostatic valve which is connected to the main drain. Dig a grouve in the floor & wall to run the pipe from the main drain to the skimmer box, normally 40mm PVC pressure pipe. It will normally be necessary to excavate for a bond or ring beam around the top of the pool which is usually twice the thickness of the pool. Beam/Wall This may have to be done by hand.
• 5.3 FITTING INCORPORATED ITEMS.
o 5.3.1 SKIMMER BOX '(S), Most pools will have one or more skimmer boxes for drawing the water from the surface of the pool. (normall allow one skimmer per 50SqM of pool surface area. The skimmer box should be mounted so that the mouth faces the prevailing winds, the skimmer box does not have to be in the deep end of the pool but must work with the wind which is blowing leaves etc across the water surface. The skimmer box should be mounted such that the centre of its mouth is 150mm below the top of the pool. Make sure that the skimmer box is set level & upright. Connect a pipe to the suction point on the skimmer box, this pipe will have to go back to the area where you have your pump & filter. (normaly 50mm PVC pressure pipe) Connect a pipe to the drain connection on the skimmer box, this pipe goes to the main drain in the base of the pool. (this pipe is normally 40mm PVC pressure pipe.) Make sure to seal the front & top of the skimmer box to prevent concrete or concrete slurry entering during concreting. (Some pools have an overflow gutter or weir or level deck, these don't have a skimmer box, see here for information) Make sure to seal the top of the main drain to stop concrete of concrete slurry getting in during concreting. The maindrain must be protected from entry of cementous compounds for the entire construction period.
o 5.3.2 MAIN DRAINS The main drain is a unit which is set at the lowest point of the pool. The main drain has a perforated pipe in its base which is set in the gravel in the pit at the deepest point of the pool. There is also a pipe which connects from the side of the main drain to the skimmer box. Set the main drain level with the deepest point required in the pool. Set the main drain level. (see photo) The main drain normally includes a removable dress ring & grated lid which are not installed at the start, these are set in the final finish of the pool.
o 5.3.3 RETURNS These are the pipes which allow the water to return to the pool from the pump & filter. Preferably use the following formula .660 kW Pump = one return 1.0kW Pump = Two returns 1.25kW Pump = Three returns 1.5kW Pump = Four returns. The returns should be set at least 300mm below the surface of the pool water or 450mm below the top of the pool. Use 40mm Class 9 PVC Pressure pipe through the walls. Set the returns such that they will drive the water in a circular motion to force floating debri on the surface to go towards the skimmer box. If you have an extra deep pool, (more than 1.8M deep), then place one of your returns 750mm below the top in the deep area. Use two elbows in the wall with each return to reduce the chance of leaking around the pipe. If only one return is used then use one 40mm pipe to feed it, if two or more returns are used then use one 50mm pipe to feed them & using 50mm tees, branch off to each return. Make sure to tape up or put caps on the ends of the returns so that concrete does not enter them. You can set up the returns with a short section of pipe protruding out past the top edge form around the pool & connect on to them after the shell is finished or you can connect them together & run the main feed line back to the area where the pump & filter will be straight away. o 5.3.4 LIGHT CONDUITS Light conduits shoud be install so that they project into the pool 450mm below the level of the water or 600mm below the top of the pool. Use orange 25mm conduit & terminate it 300mm out from the pool. Seal the end of the conduits before concreting o 5.3.5 OVERFLOW If you live in a high rainfall area, then it is necessary to have an overflow line (normally 40mm PVC Pressure pipe) installed with the base of the pipe set 25mm above the centre line of the skimmer box mouth opening. When you recieve heavy rains this will drain off excess water collected into the pool. Seal the end of the pipe before concreting o 5.3.6 MAKEUP LINE If you wish to connect an automatic makeup line to the pool to allow it to automatically fill when necessary, the run this line in 25mm PVC pressure pipe to a point a safe distance from the pool. This line should enter the pool at least 150mm below water level. & it MUST be set LEVEL back to where you install the level controller. (See notes provided by manufacturers with level controllers for more specific installation proceedures) Seal the end of the pipe before concreting
5.4 FORMWORK - BASE - STEEL • 5.4.1 FORMWORK To provide an outline edge for the top of the pool & the bond or ring beam, a form must be set up to the shape of the pool. This form can be timber of steel of fibreglass & is usually 200 to 300mm high. The top of the form is set perfectly level for finishing the concrete. (see photo) The level of the top of the form, relitave to the finished top of the pool is dependent upon the thickness of the coping or deck being used. If it is a tile or aggrigate the top of the pool may only be 20mm below the finished level, if it is a brick or paving slab deck then it maybe 75mm below the finished level, if it is concrete with Kooldeck or similar then the for will be 100mm below the finished level. If the pool is more out of the ground on one end or one side then the formwork on that side will be higher than on the other. 5.4.2 SUPPORT LAYER Once you have the floor & walls of the excavation trimmed to your requirements, then your will need to spread 75mm min of 20mm gravel across the floor area to act as a drainage layer below the concrete. This gravel must be spread to meet the gravel surrounding the main drain at the deepest point. The support layer must be covered by a membrane to stop the concrete getting into it & rendering it in effective. Many people use a layer of builders polythene but I find this to slippery to work on & prefer to use either Bitumen (tar) inpregnated paper or a thin bitumen membrane sheet. 5.4.3 STEEL Once the formwork is in place, then the steel for reinforcing the concrete must be bent & put in place. (see photo) Depending upon the pool design & the length, width & depth & the engineer, the pool will normally use either 10 or 12mm deformed bar at 200 to 300mm centers in both directions. Be sure to tie the steel at each cross over & flattern every tie wire so it does not stick up through the concrete. The steel will be bent at the top out to the formwork & will usually carry an extra three bars around the top in the bond/ring beam on the horizontal . Extra steel will be needed around the skimmer box & the main drain. (see photo) The steel must be set in accordance with an engineers recommendations but would usually be set to have at least 60mm cover on the dirt face & 75mm cover on the water face. This can be achieved with the use of plastic bar chairs available in both sizes. The steel is normally bent with a 300mm radius bend at the floor wall joint in the shallow end & up to 600mm radius in the deep end. If you are doing a flat bottom pool. then reduce the steel floor wall joint radius to 150mm. All of the steel in the pool must be connected to an earth strap along with any other metal objects (hand rails, ladders) in the pool. This earth strap must be connected back to the main house earth at the switch board. 5.5 CONCRETE, • Concreting of swimming pools is normally carried out using a spray concrete. The special spray concrete mix is delivered in to a concrete pump which pumps the concrete to a nozzle which uses compressed air to blast the concrete on to the earth & build up a thick wall encompassing the steel. (see photo) When spray concreting is being carried out, there is always the possibility of overspray. It is necessary to cover any nearby garden, parths, house walls & windows etc so that the strong, cement rich concrete does not get on to these items. The spraying of the concrete is always carried out by professional concrete sprayers.(see photo) Once the concrete has been sprayed on & cut to the finished shape. (See Photo) The concrete must be cured for a minimum of seven days. This is usually carried out by wetting the surface every 3-4 hours with a garden hose. This is ok but it is better to fully cover & tape in place a complete thin plastic cover hard against the concrete. This must be taped at the joints to stop air entering & drying the concrete. 5.6 COPING - DECKING • The coping or decking around the pool can be of many finishes & can vary from 300mm to many metres wide. Normally most engineers design a pool with a bond/edge beam 300mm wide around the top & this is covered with a material of the same width in aggrigate, brick, stone or large quarry tile. This should be laid by a compertent trades person. Most times there is a path or deck associated with the pool & this can either be at the same level as the coping or set lower than the coping, if you want to make the area around the pool look larger then set the decking at the same level as the coping. The finish on the deck can be the same as the coping or can be of a different material. If you are setting a deck associated with the pool & butting it up to the coping, there will be a expansion joint between the two lots of concrete. It is inadvisable to pave over the joint. The joint should be sealed with a joint sealer such as SIKAFLEX to stop water entering it. To give a cleaner finish to the surround, you can finish the top on the pool shell 100mm below the finished level of the deck around & pour the concrete deck right over the beam of the pool creating a joint on the horizontal instead of the vertical. This effect can be enhansed by incorporating bull nose edges etc. The form for this can be obtained from any KOOLDECK agent. You can use tile or paving or Kooldeck as a finish on the uninterupted deck area. http://www.mortex.com
5.7 INTERNAL FINISHES • 5.7.1 TILING , PART & FULL There are a number of ways in which you can finish the interior of the pool shell & all of these systems have been discussed in sections previous to the construction section. Following are some points specific to application of the finishes. 5.7.2 TILE BEAM 300mm deep plus Pebble or Marble plaster or liner. When applying this type of finish, the top band of tiles must be laid first before the coping finish. The tiles must be laid on a screed which has been set with a plaster mix approx 15mm thick which is used to give a nice clean line to the top edge of the pool & makes up for any irregularities in the concrete shell. The tiles must be laid with the joint nearest to the level 150mm below the top of the pool being perfectly level. This way the water looks level when it is at its correct level. The tiles must be laid on a cement based adhesive to give long term adhesion. When the tiles have been laid & grouted, then the pool coping should be set in place & it will be perfectly level as it relates to the tiles. If you are then using pebble or marble plaster finish, this should be applied up to the bottom of the tile line. 5.7.3 MARBLE PLASTER (MARCITE) FINISH, It must be done in one go from start to finish without a stop. Marble Plaster finishes require the use of special plastic trowls to smooth the plaster but not burn it. The dress ring component of the main drain will be installed into the plaster over the main drain hole during your application of plaster. The plaster must be covered with water starting about 4-6 hours after it is finished to allow it to cure under water. It is necessary to make sure that the water you are using to fill a plaster pool is clean & free from iron or copper or manganese or any other chemical which could stain the new finish. A plaster pool finish will need to be brushed daily from about the fourth day to the 30th day to remove any minerals or other sediment which may try to adhere to it. The pH, Alkalinity & Calcium Hardness levels must be kept correct with a plaster pool other wise the water will damage the plaster & could even make it fall off long term. The pH, Alkalinity & Calcium Hardness levels must be kept correct with a pebble pool other wise the water will damage the plaster & could even make it fall off long term.
5.7.4 FULLY TILED A fully tiled pool starts by plastering the concrete pool shell with approx 15mm thickness of 3-1 plaster. Next the top row of tiles are set in place & the subsequent layers down to & across the floor. Some tradespersons may want to finish the coping after they have done the first row of tiles, & before they do the rest of the tiles. I think this is a good idea as it means that it is easier to do the coping & if a little mess gets on the pool floor then it can be cleaned easily & does not damage anything. Tiles of the same color & size through out can be used or you may wish to run a top border of a lighter or darker color and or you may want to high light the floor wall ares with a different color or style. You have many choises of tiles but think of how you will like looking at the same tiles for the next 20 years before you make your decision. 5.7.5 FULLY PEBBLED The fully pebbled pools ususlly have the coping done first and the tradesperson will try to get the top coping as level as possible but it may never be as level as if tiles were set first. Next the pebble will be laid through out as with the tile/pebble system & all the same precautions must be taken. When applying a PEBBLE finish, extreme care must be taken to make sure that the cement residue which gets washed off the pebble does not wash down into the main drain. The dress ring component of the main drain must be installed & sealed using the pebble mix. 5.7.6 FIBREGLASSED Many pools have a layer of fibreglass laid over cement plaster which as been applied to the concrete shell. The fibreglass is usually laid in four layers. It is usual to have to wait 28 days from when the plaster is finished until when the fibreglassing can be done to allow the plaster to cure & to release its moisture. Once the fibreglass has been applied, it should last for many years. Always make sure that the applicator uses vinylester resin for the fibreglassing.
5.8 EQUIPMENT INSTALLATION • Once the pool shell is finished & before the surround concrete or decking is done, you will need to connect the pump suction pipe to the skimmer box or boxes & the filter return line to the return eyeballs. LAYOUT: Before you complete these lines, draw out on the ground the layout of your pump & filter & any accessories which will be located in the same area, eg salt chlorinator cell or gas heater or solar pump. So that you do not have pipes crossing over & looking untidy. Many times a pump will sit on the right or the left of the filter but with some filters it will only sit on the right or the left. SUPPORT SLAB: You should then bring your suction line, return line, & backwash lines up through the ground in the correct places & then form up & pour a concrete slab large enough for every thing to sit on easily. Also see ELECTRICAL CONNECTION below before proceeding. Sit all the equipment on the slab & make sure that there is good alignment for the pipes between each piece of equipment. VALVING: If the equipment is set below water level, then you will need an ON/OFF valve on the suction line & a CHECK - NON RETURN valve on the return to pool line. These should be place d before & after all equipment. It is preferable that the pump not be more than 500mm above water level unless a CHECK valve is used in the suction line below water level. (Be careful as these valves in this position tend to catch leaves etc). PUMP: The pump should be set so that you have easy access to the lint strainer on the front as it may need to be cleaned weekly. FILTER: Always sit the & filter so that you can easily access the backwash valve & also see the clear site glass on the backwash line if the filter has a site glass.. Also allow for future access for maintainance of the filter. ACCESSORIES: When installing a salt chlorinator cell in the return line, make sure to install it in accordance with the manufacturers directions otherwise you could have problems. Give careful thought as to how to comply with the recommendations & still have a neat installation with the least number of bends. If you are installing a gas heater, then you must connect the heater such that it always has water in it. This is usually accomplished by the use of positive loops on the inlet & outlet & if the is above water then a check valve on the inlet to the heater can be an advantage. You may also need to install a line (40mm) from the return line to the solar pump if you have a solar system for heating your pool. The other possible lines are: Feed to the spa as a seperate return. Pressure line for a pressure type pool cleaner Feed to jets in a spa.
5.9 ELECTRICAL CONNECTIONS • There are a number of connections which could need to be made at this point. 1. Power to the pump & filter area. For normal single pump allow 10amps For pump & lights allow 15 amps For pump & solar pump allow 20 amps For pump & spa pump & blower allow 25 amps 2. Set a post in to the equipment concrete slab on to which you can mount the control switches if you dont have a wall nearby. 3. Bring the main conduit feed to the post or the wall for the power. 4. Bring up the conduits for the lights if the transformers are to be mounted near the equipment. 5. Make sure to connect the main earth to the earth straps which come from the pool steel & hand rails or any other metal object in the pool. 5.10 SURROUND WORK Once all of the pipework & conduits and make up water etc are in place, then any surround concrete or paving can be laid in position. Before actuall concreting or paving the area, make sure that there is adiquate drainage from the actual area & also from any uphill areas adjacent. This may require the installation of actual underground drainage or sub soil aggi drains to make sure the areal is left dry & not muddy after a rain. The surround area can be of many different types of material but make sure that the material selected & used is compatible with the area It is always advisable to take some professional advise on the surround material for you are 6.0 SUB-CONTRACTING or OUT-SOURCING SECTIONS OF WORK Top
6.1 LAYOUT & POSITION This work can be done by a surveyor so that the end result is correct & perfect, a surveyor can also establish if you are the correct distance from the boundary & also if the boundary adjacent to your pool is in the correct position. Many times pools have been built after measuring from a boundary only to find the boundary was incorrect & now your pool is partly in next doors yard.
6.2 EXCAVATION This work is normally done by a sub contractor weather the pool is built by a pool builder or an owner, most pool builders use companies who specalise in digging pools. If you are building the pool yourself, then you can call around to a number of excavation companies & have them come & see your area & the pool design & give you a quote. Make sure to include the removal of the soil from site & costs to dump the soil as well ask them for a cost for rock dig incase you hit rock. This will normally be quoted per Cubic metre for rock dig. Make sure that they are insured, in case they accidently knock down a part of your house when entering or exiting the property or when digging. Make sure they are given written instructions on which trees & garden is to be removed & which is not & supervise them if possbile.
6.3 FITTING INCORPORATED ITEMS: There are many pool service companies who will also provide the service of supplying & fitting the skimmer box, returns, lights & any accessories in to the pool prior to concreting. You can also buy all the components yourself & then have a pool service company just do the installation. The pipework connections to these components need only protrude in to the soil behind the concrete area at this stage. If the area is not accessable then the pipes will have to be installed & run to the area for the pump & filter. You must do the connection from the main drain in the base of the pool to the skimmer box before setting the steel. Make sure to read all the detail in the Construction section in fitting incorporated items before proceed in here.
6.4 FORMWORK & STEEL FIXING These two trades normally go together, There are many steel fixers who dont know how to do pool steel, preferably use a subcontractor who does pool steel as a normal work proceedure as they know how to do it quickly & efficently. They will normally set up the top edge form to get the outside edge of the pool & the set the steel accordingly. You can purchase the steel yourself but remember to also buy the tie wire & bar chairs The steel fixers will normally supply the form work & labour only. PROTECTION: It is always necessary to protect any buildings, gardens, fences & adjoining property from the possibility of being coated with concrete shoul there be a problem during spraying. It is not normally a big problem but dont take any chances, there can always be a blowout of a nozzle or a blockage in one of the pipes. Dont take any chances cover everything you can. CUT LINES: If the pool has any straight sides, you will be able to set up lines using piano wire or fishing line. These will be set 150mm or 6" inside the dig line or as specified by the engineer. These lines help the concrete sprayer & cutter to provide a straight wall for you.
6.5 CONCRETE SPRAY: This is a specialist job and there are always concrete spray pump companies advertising in the yellow pages. The job of the concrete sprayer is to pump the concrete supplied by the concrete company & place it on the interior of the excavation to the dimentions of the drawings & he will have men who will cut or finish the coincrete to the exact shape ready to recieve the specified finish. The concrete sprayer will give a price in two ways, 1. Spray & cut only or 2. supply concrete & spray & cut. The concrete sprayer will be happy to include the supply of concrete in his fee if he has a contract rate with the concrete supplier or if he thinks that there will be a good lot of concrete used or if he thinks he can get away with the least amount of concrete. I would advise that you should contract with the concrete company directly yourself to supply the spray mix concrete. There will need to be certain criteria which will need to be specified to both the supplier & the concrete sprayer. Price Always negoiate a price with the supplier prior to delivery. Remember that the concrete company may charge waiting time while the truck is unloading. (It normally takes longer to unload a truck when spraying versus when the concrete is being pumped through a 4" hose for a slab. Time - For the benifit of the concrete pump people, you will need to nominate a time for delivery but it is best to advise that they dont batch untill you call to confirm. You usually do this when the concrete pump arrives on site & the concrete sprayers say they will be ready in "X" minutes. Volume: The volume of concrete used on a pool varies dependent upon the trueness of the cut or formwork of the pool. If the pool was perfectly rectangular & had an even fall from the shallow to deep end & you had excately 150mm (6") of concrete then it is easy to calculate the volume required. With a freeform pool it is not quite so easy. The easiest way to get a good estimate is: Measure from the top of the pool down the wall to the middle of the floor at three points. Take an average of that figure & multiply it by the distance around the top edge of the pool. If the engineer has specified 150mm (6") thick then multiply the area from your first calculation by the thickness of the concrete It will look something like this Top of wall to center average 3.6M or (12 Ft) Distance around top of pool 35M or (115.5 Ft) 3.6 x 35 = 126 SqM or 12 x 115.5 = 1386 SqFt Concrete thickness specified by engineer 150mm (6") Volume = 126 x .150 = 18.9 Cubic Metres Volume = 1386 x .5 = 693 Cub Ft or 25.66 Cubic yards. You will then add on another 2.5% for the beam around the top of the pool if it is a normal 300mm or(1.0Ft) wide & 200mm or (8") deep. 18.9 + 2.5% = 19.37 or 20 Cubic Metres 25.66 + 2.5% = 26.30 or 27 Cubic Yards You will give this amount to the concrete company & they will supply that amount to the last truck & then ask for confirmation of what is required to finish. Concrete Mix - The engineer should nominate a concrete mix relative to the standard for the authority under who you are building. Some times this mix design must be changed due to site circumstances so please be sure to pass on to the concrete company the engineers request. Left over - It is always a problem to get rid of any left over concrete even if it is only a few cubic feet. Make sure you have a slab prepared for where the pump & filter & heater are going to sit, you can always use any left over concrete to construct this pad. Cleanup - Most Counties & Councils now require that there is no concrete washed down the drains when the concrete trucks & concrete pumps wash up. Have someone checking all the time to make sure that any spilt concrete on the road or footpath is cleaned up & not washed down the drain. If you are building the pool yourself then you are responsible for the containment of waste. Thickness Testing - During spraying, the operators of the spray gun are experienced in the application of the concrete & will endeavour to place the required thickness on to the surface. If the sprayer is also supplying the concrete, they may try to use the least possible by only just getting to the required thickness & if you are supplying, they may tend to go thicker than really required so keep an eye on it. Slump Testing When you order the concrete the sprayers will advise what slump they want to best suit their machine & the surface they are spraying on to. Normally they will want a 65mm or 2.5" slump which is dry enough to hold up well but wet enough to pump through the small spray hose. Make it a requirement that the concrete supplier slump tests each truck & notes the figure prior to the truck dispatching its concrete. Concrete Testing You will also need to request that the concrete company or an independent testing company take two test cylinders from each truck of concrete & supply you with the results after 7 days & 28 days. This will provide the engineer with proof that the concrete has been supplied as specified. Curing Of the Pool Shell Concrete: The most important part of constructing a concrete swimming pool is correct curing of the concrete. There are many different ways which are used, such as spraying the concrete three times a day or all day with a garden hose or sprinkler or putting hesian bags over the concrete & wetting that three times a day. I have found all these work to an extent but produce different results in different climates. The only process which I know to work in all climates & I have used it from Hot Dry Desert areas to Below Zero areas & in Tropical area. PLASTIC ENVELOPE THE POOL. This is no more costly & less time consuming than the spraying of water or use of hesian bags. Simply use sheets of thin black plastic laid over the entire pool so it sits against the surface of walls & floor & then it up over the top & seal it around the edge with soil. You must use tape to seal all the joins in the plastic. This system will allow the concrete to cure in its own juice. As long as the air cannot get to the surface, the concrete will sweat & continue to cure for the seven - fourteen days that the plastic is left on. Even in below zero temperatures, the concrete will develope high temperatures below the plastic. I have never had a problem with any sort of cracking when using this method. Dont use any extra water as it may cause cracking in cold climates or evaporate off in hot climates thus reducting the temperature of the concrete.
6.6 SECONDARY PIPEWORK: At this stage while you are waiting for the concrete to cure, you can finish the pipework connections between the pool & the area where the pump & filter are to sit. Remember that in most places there is a regulation as to how close the pump & any other high voltage electrical equipment can sit from the pool In Australia it is 3.0M 10ft unless there is a minimum 1.2M high wall between. Also remember to select an area for the pump & filter which is easy access but not unsightly & that the small noise from the pump will not annoy neighbours. Remember the most important rules about running the pipes to the pump & filter area. SUCTION PIPE FROM SKIMMER TO PUMP • Never raise the pipe above water level when on the horizontal. • Never raise the pipe up & then down again before the final rise to the pump. • If the pump is more than 500mm or 20" above the pool water level, then install a non return valve in the line as close to the pool as possible. This may mean having an inspection box beside the pool to allow future maintenance. • If you install a non return valve always put a union each side of it so it can be removed for service. • Never reduce this line in the horizontal plane, always wait untill the final riser before the pump & reduce if needed on the vertical. • If your pump & filter are below water level, then install an ON/OFF plastic ball valve in this line to allow you to shut off when cleaning the strainer in front of the pump.
RETURN PIPES TO POOL • If the pool is below water level then install a check valve in this line after the last accessory, eg heater or chlorinator. • If you are using more than a 3/4 HP pump, then use 50mm or 2" pipe as a main run to the pool & then split in to 40mm or 11/2" for the various returns. • Make sure the tees you use to split the pipe to the returns are the size of the main return line & then reduce size on the branch, not on the main line. • Make sure to allow for the connection of any accessories that may come after the filter. • If you have a heater in the system, make sure to put a loop in the pipe higher than the heater before dropping in to the ground & back to the pool.
6.7 POOL INTERNAL FINISH You need to be careful here with sequencing the subcontractors for the finishing components. If you have a pool, which has a tile line around the top at water level or you are doing a fully tiled pool, you will need to arrange for the subcontractor to do the plastering for these first & then to apply the water line tile or the first row of the tile if fully tiled. Again as with the concrete, it is good to cure the plaster for a number of days if you are going to fully tile the pool. If it is just a water line tile row application then this is normally done the day after the plaster has been applied to provide a flat surface for the tiles. Unlike a bathroom a pool is tiled from the top down as the tile has to be perfectly level at water line. Therefore it is better to get a pool tiler to do the pool, not a normal house tiler. Once the top level tile is in place, then the coping can be applied as there is now a level to work to. You may consider it it is correct to have the tiler finish a fuly tiled pool at this point as the tiles have to be protected when the top surround coping is applied, some times it is better to hold after the first row, then apply the coping & then come back to a clean shell & tile that. After the coping has been applied, then you can have the rest of the interior finish applied. If you are having fully tiled, then the subcontractor can go straight on with that. Note be careful to use a good quality cement based tile adhesive, it is not necessary to use an epoxy glue or a modifier with the glue unless you expect to get a lot of ground movement. If you are having a marcite (marble dust & white cement ) finish, then this should only be applied when all the area around the pool is cleaned & the pump & filter connected & if necessary a safety fence installed as you will have to begin & continue to fill from a few hours after the marcite is applied. Also if there is any dust blowing around, the applicators can not help but get some of of it into the white finish. If you are having a pebble interior finish, then this can be applied as soon as the water line tile is finished or if it is to go to the top, then it is applied once the coping is in place. Finishes such as Fibreglaze have to wait for a 28 day curing period for the plaster before application.
6.8 POOL COPING; Many pools have a beam 300mm or 1.0Ft wide around the top of the pool which has to be finished before the rest of the interior of the pool is finished. The finishes used are covered in the construction section of this site & can be refered to there. The sub contractor will need to have his water line tiles in place to get a pefect level for the coping. In many cases the coping & the surround are one piece & this must again be done after the water line tiles & before the completion of the interior.
6.9 ELECTRICAL INSTALLATION Make sure that al your electrical connection conduits & junction boxes are in place before the interior of the pool & the surround work are finished, this will include the lights, water level controller & air buttons for a spa. Also try to make sure that you have permenant power to the filter pump so that you do not have to run extension leads. Be sure to allow for time clocks for the filter pump & pther pumps & also for controlling the lights.
6.10 EQUIPMENT INSTALLATION It is preferable to have your pool equipment all installed prior to finishing the interior of the pool. This means: • Filter Pump • Filter • Heater • Chemical Treatment • Auto Pool Cleaner Boost Pump if needed • Spa Boost Pump if Incorporated It is much easier to be able to start the equipment as soon as you have the pool full.
6.11 POOL SURROUND Another item to work on while the pool concrete is curing is the deck area around the pool, if this has not been done as part of the pool. You can set you levels to give fall away from the pool so water does not pool around the pool. Don't do to much fall towards the house unless you intend to install a gutter or drain off grating between the house concrete & the pool concrete. There are a number of companies who make concrete joint systems & inserts in to concrete for drainage but one of the best I have found is from MORTEX in Tucon Arizona (Agents in Australia in Perth & Bowral NSW) Always check these falls before the subcontractor pours the concrete. You will also need to allow for what ever thickness of finish you are applying to the surrounds. When setting out the surrounds, you can use 1" or 25mm plastic pipe set in the ground to act as a fitting for an unbrella or you may want to incorporate supports for a pagola at a later date. 6.12 COMMISSIONING THE POOL Once you pool is full of water, you will need to begin adding chemicals to adjust the water balance (see water balance section of Chemical Treatment), It would be preferable to take a sample of water from you tap to the local pool shop & have them test it prior to filling or while filling to get an idea of the pH, Total Alkalinity & Hardness levels on the water you are using. THis will allow some idea of what & how much chemicals need to be applied during & straight after filling. When you go to start the pump, you will have to prime it by removing the lid from the strainer in front of the pump & filling this with water, allowing it to run down the suction line to the pool for a minute or two. You can start the pump once you set the valve on the filter to the "Waste" position so that any rubbish in the line will not be forced in to the filter.
7.0 SURROUND DEVELOPMENT
Under the area of Construction, we covered the finishing of the bondbeam & its relationship to the pool, now we need to consider the relationship to the House & other surrounds. 7.1 How Much Area • Think about how you want to use the pool & how many people you may want to get around it in the most crowded time. Remember that in some States, the County/Council will not let you have a relaxing area inside the pool fence, only out side the fence. (see fencing 7.3) You don't necessarily need much area on "The other side of the Pool" but you should have considered this in the siting of the pool. Make sure that there is enough area for a table & chairs & some where to lay around & still keep back from the edge of the pool some. • Adjoin Garden, House, Driveway, Look at the types of material which you have used for garden edges, back of the house paths & any adjacent driveways, you will need to use a deck finish which blends in with these or is totally contrasting to these. • Types of Materials We discussed many types of materials to use for the pool surrounds, but remember that you will have to live with it for a long time so try to check with people who have had various types of finishes around their pools for 2-5-10 years to see what they look like. • Covered or uncovered With the understanding now of the effects of the sun & skin cancer, it is becoming common practice for many people to provide a large amount of area around the pool & in some cases, part of the pool to be set under cover. This does not need to be a solid cover but in many cases, it is a shade cloth or sail type cover which allows light & breeze through but keeps out a large proportion of the UV light. • Drainage This is a very over looked component of designing the surround area for a pool. There will always be water splashed around a pool with people entering & leaving the pool & the deck area is a positive collector of rain water (unless it is timber decking which allows the water through). Make sure that you provide correct falls & collection & pipework for the disposal of the area water. 7.2 Excavating the Surrounds • This should have been done as close as possible at the time of the excavation for the pool hole unless the area was left to help with keeping the work site clean. If it has not been excavated & any grass areas removed then do so being careful to observe the following. • Check for any underground utilities which may have been away from the pool excavation but which come under the surround area. • Check the relationship of the finish of the surround to the ground/grass/building/other decking it is matching up to. You don't want to have water running off the deck into the house. You also don't want water running off the lawn on to the deck. • Install any necessary drainage grating & pipeing from the area, especially from the areas where the decking meets other surfaces. This drainage will normally have to go to your stormwater system, dependent upon local regulations. • Install any conduits necessary for out door lighting or outdoor powerpoints in the area, remembering to allow for clearances of lights, powerpoints etc from the pool in accordance with the local electrical regulations. • Install any conduits necessary for outdoor speakers etc in the area, you can now buy very natural looking rock speakers & garden gnome speakers, which can be used to provide a very interesting effect around the area.
7.3 Fencing Before Filling • Many Councils & Counties now require swimming pools to be fenced from the general yard & the house, whereas others only require the yard in which the pool is situated to be fenced & the house may be incorporated as part of the fence as long as it has automatic closing, child proof doors leading to the pool access. Fencing of either style must be done before the pool is filled, so if you are having your pool Marble sheen or Marcite finished, then the fence must be completed prior to the application as the water has to be added as soon as the marble finish is applied.
7.4 Items to be considered in constructing the fence. • The fence will have to be to suit local regulations in relation to height, distance from ground to cross bars & distance between cross bars, Gates & the way they swing, heights of latches on the gates & various other items. This does not mean that you are tied to very ugly looking fences, the rulings are normally broad enough to allow the use of many different materials & looks. • Post Installation. Be careful when installing the posts that you don't dig into any pipes & conduits, plan the position of the posts carefully before hand. Preferably incorporate the post in the deck so that you do not have to cut the lawn around the posts. • Don't use a fence which blocks the view of the pool from the house, that would be a waste of the hard work you have gone through in constructing the pool & also takes away the ultimate safety feature of always being able to see what is happening in the pool. 7.5 Introduction of Privacy from Surrounding Properties. Consider the following points which are more than just the visual privacy. • Stormwater: Make sure that the surround you have to your pool does not allow water from adjoining properties to flow under fences & in to your pool area, you could have changed the whole drainage layout of the area in construction your pool to a particular level. This water may need to be diverted along the boundary or in to a stormwater system. • Leaves & other Debris: One point which should have been possibly mentioned in the positioning of your pool is the consideration of where the neighbours have trees which drop their leaves in Autumn (Fall) & which way the wind blows at that time of year. You may wish to construct a lattice barrier along a section of that fence & a little higher than the existing boundary fence which you can grow an evergreen climber on to so that it deflects the leaves from your pool. • Visual Privacy: You may need to consider the lattice as above or a hedge or some other natural barrier between your pool area & the neighbours as part of your surround development.