Definition
A pool heat pump is an air-to-water heat pump designed to heat swimming pool water, using a corrosion-resistant titanium heat exchanger and operating at low temperature lifts of 26–30 °C. Rated at 26 °C air / 26 °C water, good units reach COPs of 5–7, and full-inverter models are quieter and 20–40 % more efficient over a season than on/off types. Sizing rules of thumb start at about 0.2 kW per m³ of pool volume for a covered outdoor pool in a temperate climate.