There are several ways to use heat exchangers to heat a pool, including using a solar heating system, the heat produced by a building's heating system or the excess heat removed by an air conditioner from a home. The heat exchanger should be installed in the pool's circulation system.
A heat exchanger is a device that allows energy to transfer from one media to another. In a swimming pool, the pool water is the medium that is heated. Inside the heat exchanger, a transport liquid brings the heat to warm the water. The heat exchanger prevents mixing of the two liquids.
Because of the chemicals owners use in treating their pools, the water is highly corrosive to some metals. Manufacturers use corrosion-resistant titanium or other materials to create these special heat exchangers.
Using waste heat from an air conditioner to warm a pool reduces the air-conditioning costs. The system increases the air-conditioning efficiency by up to 40 percent, according to Hotspot Energy. Conversion transforms the air-source heat pump into a water-source unit that warms the pool at no cost. To prevent overheating the water, the system switches back to an air-source system once the pool reaches the temperature the owner chooses.