Pool heat pumps

The required heat output is calculated by multiplying the water volume in m³ by an average thermal factor of 0.25 to 0.35 kW/m³ during the standard season. To correctly size the heating unit, consider the following technical adjustment factors:

• Pools up to 20 m³: require a rated output of between 4 kW and 6 kW.
• Pools of 20 to 40 m³: require equipment rated from 7 kW to 10 kW.
• Pools of 40 to 65 m³: require outputs between 11 kW and 15 kW.
• Climate zone and wind: cold or uncovered areas require increasing the estimated capacity by 20%.

An accurate calculation ensures the desired target temperature is reached without overworking the evaporator on the coldest days.

A pool heat pump consumes up to 80% less electricity than a conventional electric heater thanks to its heat-amplification factor. While a direct-resistance system such as the Zodiac RE/LE 3 electric heater - Ref. W40LE03 generates 1 kW of heat for every 1 kW of electricity consumed (COP 1), a modern air-source heat pump delivers between 4.5 and 6 kW of heat while consuming exactly the same kilowatt of electricity, thanks to its R32 refrigerant. Using a pool cover as well reduces overnight evaporation, maximizing daily savings on your electricity bill.

Connection via a three-valve hydraulic bypass kit is mandatory to regulate the exact flow of water through the machine. This bypass configuration is always installed after the sand filter and before any salt chlorinator or chemical feeder to prevent pure chlorine from concentrating in the condenser. The bypass lets you regulate the internal heat-exchange pressure and makes it easy to isolate the heating unit during winter or general maintenance without interrupting the pool’s regular filtration.

Full Inverter technology delivers an additional 30% energy savings and a longer service life compared with traditional On/Off compressors. The functional differences are decisive in everyday use:

• Continuous regulation: the motor adjusts its speed hertz by hertz according to the water’s heating demand.
• Temperature retention: maintains heat using only a minimal fraction of its rated power.
• Quiet operation: reduces noise emissions to between 20 and 25 dB at 10 meters.
• Higher efficiency: achieves a high average coefficient of performance during extended operation.

A Full Inverter unit typically pays for itself within the first two seasons of use.

Modern heat pumps are fully compatible with saltwater chlorination as long as they have a pure titanium heat exchanger. Titanium is completely resistant to hydrochloric acid and the salt concentrations dissolved in the water, preventing pitting and perforations in the gas circuit. To protect the condenser, make sure the brine injection or electrolysis system is installed downstream of the heat pump outlet, never in the inlet line before the unit.

Units equipped with a four-way valve for automatic defrosting operate continuously at ambient temperatures as low as -7°C or -10°C, depending on the model. In cold climates, frost can build up on the evaporator when the outdoor temperature drops below 8°C; the reverse-cycle defrost system melts the ice in just a few minutes so heat transfer can continue. To protect the installation during severe winter frosts, it is essential to drain the condenser and protect the outdoor structure with a Winter pool cover for 4x3-meter pools or a breathable, purpose-made cover.

There is no need to replace your standard circulation pump as long as the filtration flow rate meets the minimum specified by the heat pump manufacturer. A standard recirculation unit such as the Winner 0.5 HP Single-Phase Pump provides sufficient flow to supply heat exchangers in medium-sized residential installations. The heat pump includes a flow switch that automatically stops its compressor if the filtration pump is switched off, preventing accidental overheating of the PVC pipes.