Heat pump pool heaters are a type of electric swimming pool heater that uses electricity to do air-to-water heat transfer instead of generating heat by electric resistance or burning fuels. As you may have already guessed, these heat pumps only work when the air temperature is higher than the water temperature and not less than 40°-50°F (4°-16°C) range. So it works in hot-to-warm searsons when the air is warm The working principle is simple: the water pump pumps pool water into the heat pump. So the water drawn from the pool passes through a filter first then enters the heat pump heater. To heat the pool water the heat pump first employs its fan to pull in the ambient air and blows on the evaporator. The warm air gets the liquid refrigerant to its boiling temperture and it turns into a warm gas. The gas then passes through the compressor where its temperature rises. The hot gas now flows into to condenser where a heat exchange happens between the refrigerant and the pool water. The cooled refrigerant becomes liquid again and returns to the evaporator where the cycle repeats. The heated water then returns to the pool through the heat pump'a water outlet.
Heat Pump Water Heater VS Fuel-Based Heaters
While considering heating solutions for your swimming pool natural question may arise as to what type of heater is preferable. The available options are the conventional propane or natural gas heaters, solar pool heaters, or heat pump heaters. Here we will list the pros and cons of fuel-based versus heat pump heaters. In either case, covering your pool with a solar cover will inhibit the evaporation and help you preserve the heat within the pool.
|Less upfront investment||higher operating costs|
|Works in any temperature||higher carbon emissions|
|Fewer mechanical components||Dependant on fuel prices|
|Heats the pool quickly|
Heat Pump Pool Heater
|Low operating costs||More expensive upfront|
|Environmentally friendy||Only works in temperatures above then 40°-50°F|
|Doesn't require gas pipeline|
Heat Pump Pool Heater Sizing
Accurately sizing a heat pump heater for your pool would require a seasoned pro because of the many factors going into consideration. The basic factors that come into play are
- pool area
- ambient air and pool water temperature difference
- wind exposure
- humidity level
- temperature drop at night
So, just to give you a sense about how this factors interact consider a pool in an area where winds are rapid, the air humidty is low, and the temperature drop significantly at nigtht. In this case, a larger sized heat pump is needed as apposed to an area with calm winds, higher humidity, and warmer nights.
You can also do a small rule-of-thumb calculation for using the following formula:
Pool area x Temperature Rise x 12
where Temperature Rise is the temperature difference between the desired pool temperature and the average temperature of the coldest month when the pool is still going to be used. For example, 200 sq f x 20°F x 12 = 48k BTU. So you should pick a heat pump that has rated BTU output nearest to the value we calculated.