Choose Your Pool and Spa Heating Options
Although swimming pools generally contain cold water which may or may not be heated, a hot water spa will always contain heated water. Most spas are fitted with electric heating equipment, while the most popular method of pool heating is a solar heating system. Heat pumps may be used to heat the water in both swimming pools and spas.
This form of heating simply exploits the heat of the sun. Although there is an obvious cost factor to install a solar heating system, once it has been installed there are no running costs. Various types of solar heating systems are available, but the basics are the same: a pump circulates the water from the pool through the solar collectors and back to the pool.
Thermostatically controlled electric heaters are generally used to heat spa water rather than swimming pool water. Once the water reaches the required temperature (which should never exceed 40º C) the thermostat maintains the level of the heat. It is not financially viable to heat swimming pool water with an electric heater because of its size and the corresponding volume of water it holds.
Until about three decades ago, gas was one of the most common and least expensive methods of heating a pool – particularly in the United States of America which lead the world’s swimming pool revolution. It is now a costly and impractical method to consider.
A relatively recent invention, heat pumps operate rather like a refrigerator in reverse, pumping air into a heat exchanger and then transferring the heat to the water. Like electric heaters, they are thermostatically contolled and keep water at a constant temperature.
Heat pumps are relatively expensive to install, and the larger the water surface to heat, the larger (and more pricey) the pump will have to be. Since they are cheaper to run than conventional electric heaters, they are a viable option for spas. The primary advantage of heat pumps is that they can be used to heat the water all year round.