The formula for determining the required pool heat pump size for a pool depends on various factors such as the size of the pool, the desired temperature increase, the ambient temperature, and the type of pool cover.

The commonly used formula is:

Q = A x ΔT x 1.163 / COP


    • Q is the heat energy required in kilowatts
    • A is the surface area of the pool in square metres
    • ΔT is the desired temperature increase in degrees Celsius
    • COP is the coefficient of performance of the pool heat pump

The constant 1.163 is used to convert the result from BTUs to kilowatts.

What is COP?

COP stands for coefficient of performance, and it is basically a measurement of how efficient the pool heat pump is at extracting heat from the atmosphere and transferring that to your pool water, this efficiency is variable based on factors such as ambient temperature, and ventilation. 

Most conventional heaters will only achieve efficiencies of about 75%, whereas a pool heat pump delivers on average about 5 times the heat absorbed. Nearly 80% of the energy needed to heat the pool comes from the ambient air. With the latest inverter models such as the Madimack Elite V3 series this efficiency can be up to a COP of 16.4 depending on humidity and temperature. 

In the below table you can see the relationship between COP and ambient air temperature measured using an 11kw Madimack Elite V3 heat pump in Sydney.

COP - Air Temp

To simplify the equation further, if we have a pool heat pump that has a COP of 5, for every 1kW of electricity consumed by the pool heat pump it creates 5kW of heat released into the pool water. From this we can determine that the higher the COP value of your chosen pool heat pump the more heat it is capable of generating per kW of power consumed, leading to a more efficiently heated pool, and less 0’s on your electricity bill.

When determining which pool heat pump is right for your situation you must also take other factors such as wind exposure, humidity, and shade into consideration. As always Clarity Pool Management is here to help you. We are the pool heating experts in Sydney, and we have helped thousands of happy customers get the most out of their pool with our efficient pool heating solutions.

Get in touch today for your free customised pool heating evaluation!