Available Modules

Pool Heaters

Swimming pool heaters heat pool water to 80 to 85°F. Three types of pool heaters are most commonly used-natural gas or propane pool heaters, heat pump pool heaters and solar pool heaters. Almost all conventionally fired pool heaters use natural gas or propane. Gas pool heaters are most efficient when heating a pool for short periods of time or for quickly heating a pool, so they are best suited to pools that are not heated on a regular basis. Unlike solar or heat pump pool heaters, gas units can also maintain any desired temperature, regardless of climate or weather. Solar pool heaters have very low operating costs and are an effective use of available solar energy. Heat pump water heaters can also cost less to operate, but cost more to purchase than gas pool heaters.

How It Works
Gas pool heaters are very much like instantaneous water heaters. Water from the pool is pumped through a filter and then the heater. Heat generated in the combustion chamber is transferred to the water as it passes through the heater and returns to the pool. In parts of California, NOx emissions from pool heaters are regulated, which requires special low-NOx burners.

Heat pump pool heaters operate similarly to heat pump water heaters, utilizing an evaporator coil, compressor and condenser to extract heat from either indoor or outside air. As the pool water passes through the filter and heat pump pool heater, the extracted heat is transferred to the water and the heated water returns to the pool. Higher efficiency heat pump pool heaters use scroll compressors; standard units use reciprocal compressors. The higher efficiency of heat pump pool heaters is contingent upon outdoor temperatures above 45-50oF. Heat pump water heaters can also draw heat from humid indoor air. Some models also reheat the cooled air.

Like their water heater counterparts, solar pool heaters use collectors to gather solar energy. As the pool water circulates through the solar collectors, it picks up heat before returning to the pool. An automatic or manual control valve can be used to divert water through or around the solar collectors depending on the temperature of the pool water.

Capacity/Energy Input
Gas pool heaters are rated by Btu output. Outputs range from 75,000 Btu to 450,000 Btu. Heat pump pool heaters are rated by Btu output and horsepower. Standard sizes include 3.5 hp/75,000 Btus, 5 hp/100,000 Btus and 6 hp/125,000 Btus.

Solar system contractors use worksheets and computers to size the surface area of the solar collectors, taking into account a number of factors including:

  • Pool size
  • Length of swimming season
  • Average regional temperatures
  • Desired pool temperature
  • Solar resources at the pool's location
  • Collector orientation and tilt
  • Collector efficiency
  • Use of a pool cover