NULITE Seal Series is a full-inverter range of air-source heat pumps for swimming-pool water heating and cooling. Six R32 models cover a rated heating output from 7.6 to 25.2 kW at Air 26 °C / Water 26 °C / RH 80 %. The manufacturer recommends them for pools from 15 to 100 m³ depending on model and operating conditions.
Inverter control and efficiency
The twin-rotary DC inverter compressor modulates output with the pool load. This reduces cycling, improves temperature stability, and lowers sound at part load. The manufacturer's table states COP values from 5.93 to 16.16 at Air 26 °C / Water 26 °C / RH 80 % and from 4.36 to 8.27 at Air 15 °C / Water 26 °C / RH 70 %; the actual figure depends on model and compressor speed.
Construction
- R32 refrigerant and full-inverter operation.
- Spiral titanium water heat exchanger housed in PVC for the pool-water circuit.
- Air heat exchanger with hydrophilic aluminium fins and copper tubes.
- Horizontal DC fan and ABS plastic casing.
- Wi-Fi remote monitoring and control.
- Water heating and cooling with ambient operation from −15 to +43 °C.
- Sound pressure at 2 m of 20–37 dB(A), depending on model and operating point.
Applications
- Private outdoor and indoor swimming pools.
- Pools at cottages, villas, and townhouses.
- Small hotel, guest-house, and club pools.
- Season extension for outdoor pools.
- Water cooling where required during hot weather.
- Retrofit of pools currently heated by electric heaters or boilers.
Selection from actual heat load
The advised 15–100 m³ pool volume is a guide, not a substitute for a heat-loss calculation. Selection considers water-surface area, pool cover, air temperature, wind, evaporation, required water temperature, season length, and initial heat-up time. Indoor pools also require separate ventilation and dehumidification calculations.
Installation and hydraulics
All models use 50 mm water connections, with an advised flow of 2–10 m³/h. The heat pump is installed downstream of filtration and connected through a bypass for flow adjustment and service isolation. The installation must provide clear airflow, condensate drainage, freeze protection for pipework, and electrical safety appropriate to wet areas.
Output and COP are based on the manufacturer's stated test conditions. Actual performance depends on ambient temperature, humidity, water temperature, flow, pool heat loss, and inverter operating point. Final sizing requires a project calculation.
