Which Type Of Pool Heater Should You Choose?

Having decided that you want a heater for your pool you then need to decide which type. The main types are gas, solar and electric (mainly heat pumps) but even within these there are a number of choices to be made.

Gas Powered HeatersThese are the most common type and they have the advantage of being able to provide heat faster than other options as they are more powerful. Units designed for above-ground pools such as the Pentair Minimax NT (more info) typically supply around 100k BTU, on the other hand a heater designed for an in ground pool such as the Jandy Lxi Pool Heater (more info) can provide up to about 400k BTU. A high powered heater will increase the water temperature quickly and is a good option if you only heat your pool occasionally.

Gas heaters are produced to use either natural gas or LPG. Clearly natural gas would be the best choice if it is supplied on site or LPG might be a good option if you already store it for home heating. If there is no existing supply of gas it may be best to look at some other form of pool heater.

Gas pool heaters also come in Electronic or Millivolt versions. Electronic models are micro processor controlled with electronic spark ignition like a modern boiler. Millivolt versions have a pilot light which burns all the time and wastes a small amount of gas. The heat from the pilot light is used to generate a small amount of electricity (about 500 millivolts - hence the name) which powers the controls. An electronic heater is the best choice unless you cannot get an electricity supply to it in which case a millivolt model will be required.

The disadvantage of gas heaters, particularly propane powers ones, is that they can be expensive to run.

Electric Heaters It is possible to buy a direct electric heater but these are only suitable for small above ground pools.

The type of electric heater that is becoming increasing common is the heat pump such as the Jandy Heat Pump (more info). Heat Pumps work by transferring heat from the surrounding air into the pool water, rather than generating heat themselves. This means that in terms of energy used to heat output they can be several hundred per cent efficient. As a result they are cheaper to run than gas heaters and are more environmentally friendly. They are also expected to have a longer lifetime than gas heaters.

Of course there are disadvantages to heat pumps. They are not as powerful as gas heaters and are best run continuously, to maintain the pool temperature. They also need a minimum air temperature of 45 degrees to work efficiently.

Solar Pool HeatersThese work by pumping the water through solar panels which are designed to collect solar energy. Although each location is different, a good rule of thumb is that the area of solar collectors should be the same as the pool area. Solar systems can be more expensive to install than gas heaters or heat pumps but should last longer and will be cheaper to run. It is certainly the best option if you want to be environmentally friendly.

The disadvantages here are that there are many more issues to consider and get right with a solar installation than with the other types of heater including solar resource, climate, local building code requirements, and safety issues. In particular you are dependent of the weather so you need to be sure that your pool will be useable for the period you require.