Swimming Pool Heat Pumps
Why would you buy a swimming pool heat pump?
A swimming pool heat pump is quite simply the cheapest way to heat a swimming pool. They are the cheapest way to heat a swimming pool because for every unit of electricity you put in to a swimming pool heat pump you get up to 5 units of heat put in to your pool water. As well as being up to 500% efficient they are the easiest type of pool heater to install and they need next to no maintenance.
Not only are heat pumps good for your wallet they are good for the environment too. They are the kind of energy efficient heater that governments all over the world are encouraging their citizens to use. We predict that by 2020 nearly all new build swimming pools will be heated by heat pumps and that just as energy efficient light bulbs are driving out the out the old incandescent light bulbs so swimming pool heat pumps will drive out gas and oil boilers.
Because, as we will see below, it is the gases inside that do all the heating the important factor in a heat pump is the ratio of power consumed in electricity compared to the heat transferred to the water. This is called the coefficient of performance or COP for short. A typical heat pump will consume 5kw of electricity whilst putting 25kw of heat in to the water making a COP of 5.0. The warmer the weather the greater the COP.
Which swimming pool heat pump should I buy?
Within our swimming pool heat pumps there are heat pumps to suit any size of pool. We rate them by their maximum output power.
The EcoWarm range are suitable for smaller pools up to about 18ft round or 12 x 24ft rectangle. We have three models, the 6, 10 and 13. These numbers equate roughly to the maximum KW output. The EW8, for example, would be ideal for a small above ground pool. With a starting price of just £695.00 these represent great value for money.
The Nirvana range of swimming pool heat pumps are the very top of the range in terms of overall performance and particularly low temperature performance. They are meant for inground pools up to 20ft x 40ft. Made in Canada, they are designed to withstand the harsh Canadian winters and have a 5 year warranty.
Calorex heat pumps are made in the UK and have been the mainstay of the UK heat pump industry for many years.
How do swimming pool heat pumps work?
Swimming pool heat pumps are closely related to air conditioning units. Instead of taking heat out of the air and discarding it they use the heat to warm up the pool water. The air doesn't have to be all that warm, even at 10 deg C a heat pump will work very well, some models will work down to 0C.
The electricity is used to drive a fan but most power goes in to driving a compressor. The compressor is used to condense a CFC free refrigerantgas. As the gas in compressed so its temperature goes up. The hot gas passes through a coil within a heat exchanger. Water from the swimming pool flows over this coil and as it cools the hot gas so it absorbs the heat. The heated water circulates back to the pool while the cooled gas becomes a liquid. The liquid gas passes through an expansion valve and then through an evaporator where it boils and turns back to gas again ready to be compressed and the whole process starts all over again. As the liquid turns back in to gas so it stores the heat that is in the air. The heat pump does not generate any heat as such it takes it out of the air and moves it to the pool water.
What should I look for in a swimming pool heat pump?
Whilst the COP is important, the most important thing is the maximum heat output. It is no use having a COP of 6 or 7 if the output is only 12kw and you need 25kw for your pool.
The hard work takes place in the heat exchanger so one made out of hard wearing titanium metal is important.
The position of the fan may be important to you. The smaller heat pumps have a vertical fan, sucking the warm air in and blowing it out sideways. The bigger models have the fan on top blowing upwards.
Heat pumps sit outside in all weathers so a fibre glass casing will never rust unlike a metal casing.
Most heat pumps are very reliable but a long warranty is a sign of a high quality swimming pool heat pump.