Whether above ground or inground your pool is going to be an expensive addition to your home, and to get the maximum amount of use out of it you will probably want to heat it at some stage.

If you are going to have a pool installed, it is worth planning for pool heating at this stage, as it can save you hundreds of dollars if you do simple things like having the plumbing connections for your heating installed and piped to the required position before the patio is layed and tiled even if you do not install your heating for a couple of years the cost of a few pipes and connections will be tiny compared to diggging up and relaying your patio.

Heating for pools falls into four main systems,

• Electric boiler
• Gas/Oil boiler
• Heat Pump
• Solar

I will look at the various ways to heat pools, and try and answer questions like "how do I choose the right pool heater?"

The British thermal unit (BTU or Btu) is a traditional unit of energy. It is approximately the amount of energy needed to heat one pound of water one degree Fahrenheit. In the case of an average 8 meter by 4 meter pool 1.2 meters deep that is approximatley 105600 pound of water, and to raise the temperature from 68 f (20c)to 93 f (30C) would require over two and a half million Btu's or 25 therms which equates to over 775kwh of electricity if using a direct heating method, such as a boiler.

There are many variables that must be considered to determine what you will spend on heating your pool. First, what size pool is it? What is the total surface square footage? the bigger the pool, the more the cost. Do you need a 5-degree rise over the air temperature or do you need a 15 to 20 degree rise? The surface area also dictates the amount of heat you loose to evaperation, and like blowing on hot coffee the amount of wind also has a direct effect on heat loss. For a light 3 mile an hour wind you could expect to loose about 11 Btu's per square foot of pool per hour so for a 500 square foot poolyou could loose 132000 btu a day, this of course can be drastically reduced by using a solar thermal cover when the pool in not in use.

There is no such thing as cheap pool heaters, but some systems are much less expensive than others.