Warm Your Pool The Eco-Smart Way

According to Energy.gov, there are a number of options for heating the family swimming pool, each with eco-smart advantages depending on the situation:

Gas pool heater. A gas pool heater is still the most popular for heating purposes. New gas fired heaters are much more efficient than older models. Gas heaters work on either natural gas or propane, and as the pump circulates the water in the pool, it passes through a filter, then to the heater. The heater’s combustion chamber transfers the heat to the water, which is then returned to the pool. These heaters are most efficient when heating a pool for a short period of time, or quickly heating the pool, making them a good choice for pools that aren’t used on a regular basis. A gas heater can keep the pool at a desired temperature regardless of the weather or climate.

When selecting a pool heater, a trained pool professional should be consulted to analyze the swimming pool to determine the proper size for the pool heater. Today’s gas pool heaters can work with up to 95% efficiency. The Energy.gov site has a table that shows the cost of gas pool heaters by location. The location and amount of usage of the pool will be significant factors in determining if the gas heater is the proper choice.

Heat pump. The principle of the heat pump is to use electricity to capture heat and transfer it from one place to another – the pump doesn’t actually generate heat. As the pool pump circulates the water, it passes through a filter, and then the heat pump heater. The heater works on a complicated principle – outside air is passed over an evaporator coil, which absorbs the heat from the outside air. The liquids in the evaporator coil turn into a gas, pass through a compressor, then a condenser, which transfers the generated heat to the cooler pool water circulating through the heater.

Heat pumps work efficiently as long as the outside temperature remains above 45 to 50 degrees Fahrenheit. If the air outside is cooler, these pumps use more energy.  The pumps typically cost more than a gas pool heater, but cost much less to operate on an annual basis, due to their higher efficiency. In the long run, they can be more money saving, because the pumps last longer than gas pool heaters. The site has a table showing the costs of heating a swimming pool using a heat pump, by location.

Solar pool heaters. The choice to use solar panels can lead to significant reduction in heating costs for the swimming pool. The solar systems are cost competitive with both gas and heat pump heaters, but they have very low annual operating costs. Particularly in warm and sunny climates, solar pool heating is a very cost effective use of solar energy. Solar heating systems include a solar collector – consisting of solar panels which will heat the water as it is circulated through the system, allowing the sun to provide the heat. A filter removes debris, a pump circulates the water through the filter and collector, and a flow control valve diverts pool water through the collector.

The type of solar pool collector will depend on the climate and the amount of use. If temperatures will only be above freezing, an unglazed system consisting of heavy duty rubber or plastic will be installed. These are the less expensive types. For colder climates a glazed system, consisting of copper tubing, aluminum and a glass covering will be needed, which increases the cost. However, the solar systems typically last longer than gas and heat pump systems. 

Evaluating the parameters of the swimming pool site will determine which system will provide the most energy efficient system for the long run. Once the proper pool heater is installed, then you hear things like “Come on in, Mom, the water’s fine,” which makes any parent smile.

Becky Flanigan writes freelance for In The Swim.com.  She has 3 kids with her wonderful husband – two boys and a girl – and two lovely golden retrievers.  When she’s with her family, she spends many happy hours at their swimming pool, watching the kids and dogs splash and play.  She is also an ambitious runner, and diligently training for her first half marathon.