How does a Swimming Pool Heat Pump Work?
Heat pumps work on the opposite principle of air conditioning units. It
extracts heat from the surrounding ambient air, allowing it to heat the
refrigerant, and then compresses it, making it even hotter. It is then passed
through a heat exchanger where the water is heated. The refrigerant is then
allowed to expand again, cooling it down and allowing it to absorb heat from
the surrounding air again. So only a little electricity is needed to run the
fans and compressors, while the heat is provided indirectly by the sun.
A modern pool heat pump is a very efficient water heating device that
uses a small amount of electricity to drive the compressor, which is the heart
of the heat pump. The thermal energy produced is more than five times the
electrical energy used to drive the compressor in standard on/off models, and
ten times more for the inverter technology unit. This means that the power
consumption of pool heating can be divided by up to 10 compared to normal
electrical element heating.
Instead of relying on sunlight or direct radiation, a heat pump extracts
thermal energy from the air at any time of the day or night, so it's actually a
different form of solar heater. Even in extremely cold conditions (-5°C or
less), heat pumps can still provide more than 60% energy savings. In most
cases, in South Africa, where our daytime temperatures are relatively warm, the
efficiency will be at least 5 times that of an elemental hot water system. A
heat pump looks similar to an air conditioner and can be installed either on
the floor or on a wall bracket. It's quiet and unobtrusive with a user-friendly
controller, has no greenhouse gas emissions, and requires little maintenance.
Heat Pump Cycle
1. One unit of electricity (you pay for it) runs a compressor that draws
vaporized freon gas from a liquid-filled evaporator tube. This creates an
intense cooling effect (like sweat evaporating from your skin and keeping you
cool). The gas absorbs four units of heat from the air flowing outside the
2. The compressor squeezes the gas so that its temperature climbs above
200° F (93° C) Result: Five units of heat are added to the gas.
3. High temperature and high pressure gas flows through the inside of
the condenser coil. The cooler 80° F (26° C) pool water absorbs five units of
heat from the freon, cooling it back to a warm liquid.
4. Warm liquid is forced through a valve. As the pressure drops, it
rapidly expands and becomes an extremely cold liquid. This liquid flows back to
the evaporator at 1, where the cycle is repeated.
Pool heat pumps are designed for recreational water heating (ground,
above-ground or above-ground swimming pools, spas, hot tubs, swim spas, etc.).
If you have an air conditioner, dehumidifier, chiller or refrigerator, you
already have a heat pump.
All of these devices use the same reliable technology, using electricity
and a sealed refrigerant compression system to transfer heat from one place to
another. This provides five to seven units of heat to your pool water.