Buying a Swimming Pool Heater - What Are the Options?

Deciding which type of swimming pool heater to buy is no easy matter as there are many alternatives from which to choose. To complicate matters further, different heaters suit different sizes of pool and different levels of use and even seasons of use.

All commercially available swimming pool heaters for domestic (indoor or outdoor use) fall into one of the following categories:

* Gas and propane burning heaters
* Condensing heaters and heat pumps
* Oil fired stoves
* Heat exchangers
* Electric heaters
* Solar systems

All of the above offer different heating and economy advantages that will vary depending on pool size, average usage, regional climate and whether the pool is situated outdoors or indoors.

Cost efficiency

Pool heaters powered by solar energy, heat exchangers or a heat pump can be highly cost effective when used in conjunction with small to medium sized swimming pools. However, these heater types cannot deal with large volumes (or flows) of water and they are further limited by the level of heat increase that they can provide.

They are ideal when the water is maintained at a constant temperature for regular use and in environments where the ambient temperature is always moderate (rather than cold).

Heating power

When it comes to raw energy and heating power, a boiler, stove or condensing boiler will offer the most versatile methods of raising the temperature of a pool's water.

These heaters can deal with high flow rates (i.e. large volumes of cool water) and they can also raise water temperatures from very cold to very warm in comparatively short periods of time This means that they are ideal for situations where a pool may need to be used at relatively short notice or where the ambient water temperature is low and requires a rapid and powerful injection of heat.

Heaters of this type offer more power and a high flow-through rate, but this is balanced by high running costs and rapid energy consumption.

Which is the best heating system

Selecting the right heating system for any swimming pool environment necessitates careful consideration of several factors. These include:

* The pool's size - in other words the volume (and flow rate) of water to be heated.
* The required bathing temperature.
* The level (or regularity of use).
* The intended swimming season.
* The budget.

Making the choice

As a general guide, solar energy and heat exchangers are ideal for raising swimming pool water temperatures by a few degrees. They are comparatively cheap to buy and require a simple installation. For this reason they are ideal for mild climates or for use in summer.

The big limitations on solar and heat exchanger heaters relate to their inability to heat water across a large temperature margin, or to heat large volumes of water. For this reason they are limited in certain applications.

Heaters based around boilers and condensers generally have gas, propane, oil, or solid fuel as their energy source. For this reason they can be expensive to run, but the fact that they burn energy also makes them very powerful and equally versatile.

Boilers and condensers can heat a cold pool to a comfortable bathing temperature very quickly and they can be purchased and fitted with a heating capacity that matches the pool size. They also have precise temperature controls enabling their water temperature to be set or varied with great accuracy and ease of use.

On the down side this "easy access power" does come at a cost and boiler based heaters can be expensive to run. But equally they offer complete usability at any time of the year and in any ambient temperature.

With this kind of heater it is possible to swim in warm water in an outdoor swimming pool in the middle of a freezing winter. This makes this kind of heater ideal for the daily or regular swimmer.

Combined heating systems

For pools with significant water volumes that experience regular use it can sometimes be advantageous to have a dual heating system.

This is because the most expensive use of a pool's heater is in the initial raising of the water's temperature from a "cold start". However, this "warming of a pool's water can be done at zero running costs by using solar energy.

Solar matting or panels can act to bring the water up to a tepid to luke-warm temperature, thereby freeing the boiler or condenser to provide the heat required to make the bathing temperature comfortable. This can reduce pool heating fuel bills, dangerous emissions and make the swimming pool less dependent on fossil fuel for its heat.

Naturally a dual heating system requires a greater initial investment than a single system, however the reduced energy burning costs can make this kind of set-up more cost effective over the long term for pools that are used regularly.