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:

30kW Heat Pump - 7GP30-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 150m² for most of the North Island, up to 125m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 113m² for most of the North Island, up to 102m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 91m² for most of the North Island, up to 75m² for the Central North Island and South Island. 

35kW Heat Pump - 7GP35-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 180m² for most of the North Island, up to 150m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 135m² for most of the North Island, up to 115m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 101m² for most of the North Island, up to 90m² for the Central North Island and South Island. 

50kW Heat Pump - 7GP50-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 225m² for most of the North Island, up to 200m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 189m² for most of the North Island, up to 161m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 144m² for most of the North Island, up to 122m² for the Central North Island and South Island. 

65kW Heat Pump - 7GP65-3 (Three Phase)

• Residential Pool (up to 4 hours per day uncovered) with a surface area up to 270m² for most of the North Island, up to 250m² for the Central North Island and South Island.
• School Pool (up to 6 hours per day uncovered) with a surface area up to 240m² for most of the North Island, up to 200m² for the Central North Island and South Island.
• Commercial Pool (up to 12 hours per day uncovered) with a surface area of up to 180m² for most of the North Island, up to 154m² 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.