Solar Pool Heating

Solar heating swimming pools can save thousands of pounds per year. The panels can be easily integrated into the existing pumping system

Swimming pools are an ideal application for solar water heating, as the temperature required is quite low - under 30oC. Many installers will recommend flat plate collectors because traditionally they were cheaper than evacuated tubes and the amount of panels required is much larger than for heating domestic hot water. However, if you can buy high efficiency evacuated tube solar panels for the same price, you might as well enjoy solar heated pool water for a greater proportion of the year instead of just in July and August.

If you use flat plates, a rule of thumb for calculating how many you need is to fit the equivalent of 50% of the pool's surface area. For vacuum tube panels, this is reduced to 25 to 30% ( depending on the type of pool, level of insulation, pool covers, indoor/outdoor, above/below ground level etc) and of course they will carry on working in the autumn, winter and spring. Our 20 tube panel is 2.25m2, so (working on the 25% figure) each panel will heat 11m2 or pool area. A 40m2 pool would only need 4 panels. Compare this to the annual cost of heating a pool using conventional fuel! Large pool installations can pay for themselves in under 18 months.


Installation is very simple. If you have chlorine you will need to fit a stainless steel heat exchanger (this is because chlorine causes copper to corrode). These are available from pool suppliers (they are needed for conventional heating methods for the same reason). If you don't have chlorine, you can simply put the solar panel in line with the pool filter, so that the pump directs water through the panel before returning it to the pool. As the panel will NOT radiate heat on cold days (unlike a flat panel), heat losses will be confined to the pipe runs only - so you do not necessarily need a controller, although one can be fitted to control a 3-way solenoid valve to divert the water through the panel when it is hotter than the pool water.