The best way to heat a pool in Australia is to use a combination of solar PV panels to create power for your heat pump water heater during the day when the sun is shining and to use a swimming pool blanket to retain this heat and reduce water evaporation. For an average Australian swimming pool of around 40,000 litres, you will lose between 200 and 280 litres of water per day during a 6-month swimming season. This adds up to about the total volume of your pool water lost in just one season if you don't use a pool blanket.
Pool heat loss:
Swimming pool heat loss during the shoulder seasons is significant and particularly so in regional areas away from the coast where there is a wide difference between the night time air temperature and the swimming pool water temperature, and when sunshine is weaker. You will need a huge amount of energy to replace this heat loss during the day if you do not use a pool blanket, and will need to spend a lot more on a larger 3 phase heat pump to generate this heat energy.
Using solar and heat pump to heat your pool:
A heat pump does not require sunshine to operate effectively because it uses the heat from the air. On the other hand, solar heating coils on your roof require direct sunshine and also take up space that could otherwise be used for solar PV panels to make power. Solar heating coils are also most effective in the middle of summer when the sun is shining strongly but you don't really require heat for you pool then. A heat pump can operate very effectively when it's cold and wet outside and in the shoulder seasons when combined with a pool blanket.
A heat pump will simply turn off when its thermostat detects your pool temperature has reached the set temperature. In the middle of summer, it may not need to run at all so the power from your PV panels can be used for other purposes or exported into the grid to earn money.
Why use a heat pump?
The reason why a heat pump is so effective for heating a swimming pool is because it's efficiency (called coefficient performance or COP) in raising water temperature to a moderate temperature of around 30 degrees is very high. Just 1 kW of power will generate around 5.4 kW of heat energy to heat your pool by exploiting the heat in the air. Heating a pool with gas is very expensive and will be more so in the future with rising gas prices so is not a good option for heating your pool.
Another advantage of a heat pump is that it does not degrade during hail storms storms or with the activity of birds or possums on your roof. A swimming pool heat pump also works well in shaded areas.
How noisy is the pool heat pump?
The noise from a heat pump is similar to the noise from an outdoor air conditioning unit. This noise can be quietened by placing the heat pump in your swimming pool equipment area with a structure around it that reduces noise transmission whilst still allowing the heat pump to expel air through a vent. If this structure has absorptive material inside, it will attenuate the sound waves and reduce the noise level.
How much does a pool heat pump cost?
The cost of a swimming pool heat pump water heater for an average 40,000 litre pool is $7,683 (+ GST) from Siddons, plus freight and installation. Find out more by clicking here.
The cost of a 5.5kW solar system to run your heat pump and other household appliances using tier 1, high quality solar panels and high quality Fronius inverter is $7,900 (+GST)), supplied and installed.