Swimming pools have the reputation of being energy hogs, but high electric bills are not inevitable. A number of relatively simple changes can cut operating costs by half or more.
Most pool energy goes to power the circulating pump, with much smaller amounts needed for cleaning and water treatment. In heated pools (which make up only 10 percent to 20 percent of all residential pools), energy use varies widely depending on family preferences and use patterns.
Pumps are the heart and soul of any pool. Most pools rely on a single-speed, 1.5- to 2-horsepower pump that runs at full speed for 8 hours a day or more. More efficient pool pump options include:
- Replace an existing single-speed pump with a high-efficiency single-speed pump. High-efficiency pumps use 8-10 percent less energy and are only marginally more expensive than standard pool pumps.
- Exchange an existing single-speed pump for a two-speed pump that won’t go “full throttle” on a single high speed all of the time. By running at a lower speed for 16 hours per day, you can save 60-70 percent on electric bills. A two-speed pump will cost an extra $100 to $150.
- Replace an existing pump with a variable-speed pump that varies speed – and, therefore, electricity consumption –with the required workload. Although a variable speed pump will cost about $650 more than a basic pump, it saves the most energy by far – nearly 90 percent – and offers the greatest operational flexibility.
In addition to replacing an inefficient circulating pump, consider these measures:
- Use a bigger filter. An oversized filter will result in less pressure loss on the pumping system, enabling greater water flow with less energy. The larger filter will also last longer between replacements.
- Use bigger pipes – typically 2 inches in diameter instead of 1.5 inches – and large-radius elbows. Making the flow path smoother reduces pressure loss and pumping power.
- Downsize the pump. Most pools are designed with an unnecessarily large pump. Going from a 1.5 or 2-horsepower unit down to a 0.75- or 1-horsepower model can reduce pumping energy by half or more – often with no loss of performance.
- Control pump run times. Depending on the effectiveness of your filtering system and the amount of use the pool gets, it may be possible to save significant pumping energy just by running the pump less. The normal target is to cycle the pool’s volume through the filter one or two times per day, but you could try fewer hours and see if the pool still is acceptably clean. Although this no-cost measure is appealing, it will not save as much money and energy in the long run as replacing an inefficient pump with an efficient two-speed or variable-speed pump.