The heat pump most suited to each situation is determined by a number of factors; the surface area of the pool, pool use, whether the pool has a cover and the time the pool is covered, local temperature and weather conditions.

For heat pump sizing for the duration of use your require, please contact Hot Water Heat Pumps. As a general guide to heat pump requirements for an extended season of swimming from mid October to mid April:

20kW Heat Pump - 7GP20-1 (Single Phase) & 7GP20-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 95m² for most of the North Island, up to 80m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 67m² for most of the North Island, up to 58m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 56m² for most of the North Island, up to 44m² for the Central North Island and South Island. 

23kW Heat Pump - 7GP23-1

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 110m² for most of the North Island, up to 95m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 82m² for most of the North Island, up to 71m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 69m² for most of the North Island, up to 58m² for the Central North Island and South Island. 

25kW Heat Pump - 7GP25-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 120m² for most of the North Island, up to 105m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 85m² for most of the North Island, up to 75m² for the Central North Island and South Island.
• Commercial Pool (up to 6 hours per day uncovered) with a surface area of up to 74m² for most of the North Island, up to 63m² for the Central North Island and South Island. 

Ideal applications

• Swimming pool
• Spa heating
• Hydroponics

All residential heat pump pool heater models carry a comprehensive two year parts and labour warranty, including the compressor, evaporator coils, heat exchanger and refrigeration systems. The titanium tube within the heat exchanger is covered against corrosion for 30 years for residential use and 10 years for commercial use.

Heat pump water heaters are fitted with protection systems to prevent damage in the event of a malfunction. For example a flow switch to ensure the heat pump cannot operate without water flow and other refrigeration safeties. If a problem is identified, the unit automatically shuts down before damage can occur.