A heat pump simply moves heat from the air and transfers it to the pool/spa water. A heat pump uses a refrigeration cycle exactly like your refrigerator or air conditioner uses. A proven safe, economical and very trouble-free system.  A heat pump allows you to heat your pool or spa economically. Depending on energy costs, an AquaCal heat pump can save you up to 80% over propane gas, 50% to 70% over natural gas, and over 600% against electrical resistance heaters found on most spas. This is the reason why thousands of customers choose a heat pump to heat their pool, rather than alternative types of heaters.  If you plan on heating your pool, a heat pump makes the most sense, and the most economical heat pumps feature SCROLL compressors.  AquaCal's HeatWave heat pumps were the first heat pumps to feature SCROLL compressors as their standard compressor.  AquaCal units feature ThermoLink Titanium Heat Exchangers.  We have models that can heat or cool the water, depending upon the season and circumstances. There are models for every pool and spa application, residential or commercial, allowing us to build the most durable, most cost efficient heat pump with the industry's strongest warranty to back it up!  All are fossil fuel free and using only "green" R410A Refrigerant.