New systems, better application of technology, and progressive thinking bring sustainability to backyard swimming pools.
Today, there are 4.5 million in-ground pools, which use $1.1 to $1.6 billion in energy costs per year, according to the Natural Resources Defence Council (NRDC) in its report, “Synergies in Swimming Pool Efficiency”. Our nation’s residential in-ground swimming pools consume 9 to 14 billion kWh and 36 to 63 million therms of natural gas each year, resulting in Co2 emissions of approximately 10 million tons per year – or the equivalent of 1.3 million cars and light trucks on the road per year.
According to NRDC, if all residential pools were upgraded to reduce pumping energy by one-third, and all heated pools were also upgraded to reduce heating energy by one-third, the total annual savings would be worth more than $360 million. Carbon dioxide emissions would be reduced by at least three million tons – the equivalent of removing all of San Antonio’s cars from the road for one year.
Pump It Down
If you took the worst 30 year old refrigerator on the market, you wouldn’t come anywhere near the savings you’d get from replacing a single speed pump with a variable speed pump. The typical pool pump used today is a single speed. It is sized to take on the toughest job, like running the jets on the spa or cleaning the pool. Trouble is, it runs at that level even when it’s not necessary. Typically, a pool needs much less energy and water to do standard filtration. The pumps are running every day at max speed for once in a blue moon when you turn the spa on.
A variable speed pump can be programmed for the exact requirements of each pool task and the optimal speeds tend to be slower speeds, with the ideal pump running longer at lower speeds and adjusting to requirements only when needed. Reducing the speed in half reduces the energy use to 1/8 the higher speed.
The NRDC estimates that in a community with a four month pool season, upgrading from a singe speed to a variable speed pump can save the average homeowner $350 a year. The organization conduted a study on Pentair’s IntelliFlo variable speed pump and noted that the system reduces energy use up to 90%. Pentair reports customer savings as high as $1,360 annually, with an added advantage of quieter operation (about 7-10 decibels). There is more of an initial investment, but it will pay for itself in two years or less.
Consider the Green Builder’s show home, The ReVISION House, which debuted at the Las Vegas IBS show in January. They replaced the 1.9 kW pool pump that runs at 180 watts, eight hours a day, and realized a $1,100 (annual) savings.
But that’s not the only good news on the efficiency front. Other technology changes and best practices can help, too. For example, new sophisticated control systems allow pool owners to operate their pools outside peak energy use periods. In addition, the pump itself can run more efficiently if larger, straighter pipes, sweep elbows, lower pressure backwash valves, and oversized filters are used.