Heating a pool without a pool blanket is like heating a house with the windows open, it doubles the cost of operating a heat pump or gas heater, and decreases the effectiveness of a solar heater. Types of Heating Systems Solar Heating Systems are best for recreational pool use and recommended for those who are comfortable with pool temperatures ranging from the high 70's to the mid 80's, during the swimming season. Solar systems generally last 15 to 20 years, operate economically, and require minimal maintenance. Solar systems, utilize the sun's heat, and unlike gas or electricity, generally pay for themselves in about two years. Heat Pumps are best for those who enjoy swimming regardless of the weather, for homes that may not be solar feasible, and for those who swim for therapeutic reasons and require constant temperatures.
Heat pumps are complex pieces of equipment and there's quite a range in quality and price.
Heat pumps are also a form of solar heater, as the sun-warmed air contributes to the heating efficiency of these units. Gas is best for heating pools or spas quickly for short periods. Gas is effective, but expensive. For example, a customer may only heat their pool when guests and grandkids visit or they may spend short periods of time at a second home and want the pool to be heated while they're there. In this situation gas is recommended.