Swimming pools provide a great way toexercise and beat the summer heat. Buildingand maintaining a pool, however, alsomeans relatively high costs added to yourhousehold’s budget. There are severalways that you can reduce operating andmaintenance costs, lower water consumption,and conserve heat if you heat yourpool. Many people heat their pools toextend the swimming season and/or tokeep it at a temperature that they are personallycomfortable with. This lets themenjoy the full value from their pool. Solarpool heaters are an option to heat the poolwith “clean” energy from the sun, and canreduce heating costs.This fact sheet discusses options for reducingthe costs for operating and heatingyour pool.Optimizing WaterFiltration andCirculation PumpingA study by the Center forEnergy Conservation atFlorida Atlantic Universityshows that pool ownerscan save energy andmaintain a comfortablyheated pool by usingsmaller and higher efficiencypumps, and operatingpumps less each day.In this study of 120 pools,some pool owners savedas much as 75 percent oftheir original pumping billwhen they used both conservationmeasures (seetable on page 2).
Sizing the Pump Right
When a pump wears out or can’t berepaired, a pool owner typically installs alarger one, thinking that “bigger must bebetter.” Instead, a larger pump mayincrease the costs of pumping and maintenance.To choose the right size pump, consultdesign charts that match the hydrauliccharacteristics of the pump to both thepiping and the pool’s flow characteristics.A local pool supply dealer should haveaccess to these charts.The Florida study shows that a 0.75 horsepoweror smaller pump is generally sufficientfor residential pools. Smaller pumps,which cost less, can be used if youdecrease the pool circulation system’shydraulic resistance. This can be donethrough one or more of the followingways: substituting a large filter (rated to atleast 50 percent higher than the pool’sdesign flow rate), increasing the diameteror decreasing the length of the pipes, orreplacing abrupt 90-degree elbows with45-degree elbows or flexible pipe. Thesetypes of changes can slash up to 40 percentoff the pump’s use of electricity (seetable above).
Circulating the Water
Another way to save energy is to reducethe pump’s operating time. Pool pumpsoften run much longer than necessary.Pool owners need to understand the reasonsbehind circulating the pool’s water.Circulating water keeps your pool’s chemicalsmixed. However, as long as the watercirculates while chemicals are added, theyshould remain evenly mixed with minimaldaily circulation. Secondly, circulating thewater keeps the pool free of debris bydrawing water out and through the filter.It is not necessary to recirculate the watercompletely every day to remove debrisand clean the water. One complete circulationusually takes between 6 and 12 hoursper day. But this may be longer than necessarysince most debris either floats orsinks, and can be removed with a skimmeror vacuum. After about an hour, mostof the pumping power is wasted by circulatingclear water and does little toimprove the water’s quality.Furthermore, longer circulation does notnecessarily reduce the growth of algae.Instead, using chemicals in the water andscrubbing the walls are the best methods.In the Florida study, most people whoreduced pumping to less than 3 hours perday were still happy with the water’squality. On average, this saved them 60percent of their electricity bill for pumping.Combined with using a smaller sizepump, pool owners saved up to 75 percentof their original electricity bill for pumpingwater (see table above).One last simple measure for saving moneyis to use an accurate timer to control thepump’s cycling. Use a clock that can activatethe pump for many short periodseach day if debris is a problem. Runningthe pump continuously for, say, 3 hoursleaves the other 21 hours a day for thepool to collect debris. Several short cycleskeep the pool cleaner all day.



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http://nrel.gov/docs/fy00osti/28038.pdf