Benefits of Heating Your Pool
In most of southern NSW including the ACT the comfortable swimming season is around three to four months of the year. Cool nights or inclement weather reduce water temperatures quickly and confines use of the pool to the more hardy among us. The addition of a heater gives you the potential to maintain your preferred swimming temperature for an extended season or year-round. Just imagine the benefits.
The number of times people swim is dramatically increased. Your pool will become an oasis with crystal clear warm water, reminiscent of your last tropical island holiday.
There are four basic types of pool heating systems. These are Solar, Gas, Electric Heat Pumps and Electric Elements. The best system for your pool is determined by numerous factors including your needs, desires, budget and physical location of the pool and house.
Solar Pool Heating
Solar heaters for pools are extremely popular because of their obvious advantage in using free energy from the sun.
Solar heating systems work by direct heat transfer. The water from your pool is circulated through the collector, which is usually located on a roof. Most systems utilise a digital controller, which activates the solar pump and sends water to the roof whenever there is sufficient sunshine, provided that the pool is not already at your desired temperature.
Solar heating is perfect for those recreational pool owners looking for a heating system that has minimal operating cost and provides a warm pool when people most want to swim. That is, on fine summer days. After the initial installation costs, the only additional expense is the operation of the dedicated solar pump (which most manufacturers recommend). Because of its reliance on weather conditions, the solar system will provide a consistency of temperature rise at the edges of the season in Spring and Autumn, at least doubling the time the pool may be used in comfortably warm water.
When considering the installation of a solar heater, the all-important factors are the collector area proposed, collector design and quality of material.
There is only a fixed rate at which the sun will provide energy, so the larger the collector the more heat will be gained. As a general rule the collector should be equal to at least 80% of the area of the pool, although 100% coverage would be more ideal.
Results improve as the collector size is increased. Other points that are important when considering solar are the pitch and directional aspect of the roof, that is, which way it faces. A roof facing north is most favourable because it will receive the maximum amount of sunlight. Any shading of the roof by large trees will also be considered. Another important factor is the location of the pool and how much it is affected by the shade and wind.
Gas heaters are used in large numbers in pools and spas and give great flexibility to the pool owner, because of their rapid heating ability and robustness.
Gas heaters can easily maintain any desired water temperature as typical sizing is based on providing heater capacity capable of achieving a 14oC rise in water temperature in 24 hours. This allows a cold pool to be heated to a beautiful 28oC – 30oC in around one day, even in winter. This heating strength makes fas perfectly suited for pools that are used for entertaining.
From the point of view of heating cots, the constant maintenance of pool temperature with gas is quite viable during the warmest months of the year. Whereas the solar heated pool will vary in temperature during this season, the gas-heated pool is maintained at the owner’s preferred temperature. Gas heating costs will be modest, as the heating requirement of the pool is relatively low. Likewise, the gas heater owner has the added flexibility to heat for specific events such as parties or BBQ’s, or for longer periods such as September school holidays. A gas heater is ideally suited to be added to a solar system, as it will offset solar’s inability to work at night or in poor weather.
Electric Heat Pump
A most modern development in pool and spa heating is the electric heat pump. These units are for those pool owners who want to swim most, if not all, of the year.
Heat pumps work like a reversed air conditioner. Instead of taking air from a room or building, removing the heat and returning it, a heat pump takes large quantities of air from the atmosphere, and transferred to water from the pool or spa passing through the unit.
The characteristic of the heat pump of absorbing heat value from air means that the unit has a low electrical input relative to its heat transfer. Heat pumps output heat at a rate of around 4:1, relative to their energy input. This greatly reduces total energy consumption. The capture of solar energy from air means that he heat pump’s output and efficiency will vary with air temperature. Higher efficiency is gained in more temperate locations but heat pumps are capable of maintaining pool temperatures year-round. Combined with their high-energy efficiency, heat pumps are available for connection to off peak electricity pricing.
Electric Heat Element
Element heating works much like an electric kettle in that there is a direct heat transfer between the immersed element and the pool water. The small physical size of the units makes them ideal for use on spas and small pools, and where plant space is at a premium or where gas supply is not available and the special installation needs of a heat pump cannot be met. They also provide an excellent back-up system for solar heaters.
The heating of a spa requires one of the powered forms of heating, that is, either gas, heat pump or element. The spa may be heated by a dedicated heater or by the pool heater, if the hydraulic design allows. Where a single heater is installed, there will be a need to alter valve settings to circulate the water between the spa and heater only, with the pool isolated while a fast temperature rise is achieved in the spa.
Pool blankets are one of the most cost effective elements of any heating system. Since 70% of all heat loss is evaporative and convective, the blanket provides a simple barrier and cuts almost all of these losses when in use. The net result is significant savings in heating costs.