Solar Pool Heaters and Heating ... use A Solar Roof
Heating Your Swimming Pool With Solar Energy
In places like California, Texas, New Mexico, Australia and South Africa many homes have open-air swimming pools. Despite the remarkable sunny climates and warm temperatures of such places many swimming pools remain too cold for swimming most of the year. To fully enjoy the major investment of a home swimming pool the pool water should be heated. Since locations of high swimming pool density have long hours of daily sunshine the answer is to use the sun's rays more efficiently and collect the sun's heat by using a solar pool heater for heating the water
Introduction to Solar Pool Heaters
In very simple terms solar pool heaters consist of a flat energy collector
consisting of numerous solar heater cell (these look like small black glass
windows from a distance). These solar cells collect the sun's rays and turns
these rays into electricity and this electric power energy in turn is used to
heat water pumped through the pool solar heater system.
The solar pool heaters collector is normally placed on the roof of the house facing South in the northern hemisphere and North in the southern hemisphere. This way the solar collector works most efficiently in collecting the sun's rays
So think of solar pool heaters as a system of pump, pipes and a solar collector through which the water is pumped on its way back to the pool. Continuous recirculation means eventually all the water in the swimming pool gets warmer ... at least until the sun goes down.
A brief description of solar power
Solar power describes a number of methods of harnessing energy from the light of the Sun. It has been present in many traditional building methods for centuries, but has become of increasing interest in developed countries as the environmental costs and limited supply of other power sources such as fossil fuels are realized. It is already in widespread use where other supplies of power are absent such as in remote locations and in space.
As the Earth orbits the Sun, it receives approximately 1,400 W / mē of energy, as measured upon a surface kept normal (at a right angle) to the Sun (this number is referred to as the solar constant). Of the energy received, roughly 19% is absorbed by the atmosphere, while clouds on average reflect a further 35% of the total energy. The generally accepted standard is 1020 watts per square meter at sea level.
After passing through the Earth's atmosphere, most of the sun's energy is in the form of visible and ultraviolet light. Plants use solar energy to create chemical energy through photosynthesis. We use this energy when we burn wood or fossil fuels. ... reference http://www.wikipedia.com
More on solar Swimming pool heaters
Metal solar pool heaters or collectors are generally made of copper tubing mounted on an aluminum plate. The metal collectors last longer than plastic ones, and they are slightly more efficient in absorbing heat, therefore requiring less roof space than plastic collectors.
The disadvantage of metal collectors is that the copper tubes may react with your pool's walls, producing discoloration that can only be removed by draining, cleaning, and repainting the pool. However, this problem can be entirely avoided if the pH level is always maintained above 7.2.
Your solar pool heater's collector should require very little maintenance provided the pool's chemical balance and filtration system are regularly checked.
Since all swimming pools require a pump and related plumbing, the addition of a solar pool heater to an existing installation can be relatively simple. However, unless you are experienced with plumbing and electrical wiring, it is advisable to allow a professional to install your system. Often the existing swimming pool filter pump can be used to circulate the pool water, though you should be sure it is able to maintain a high flow rate in order to keep the panels cool and operating at a high efficiency.
It is generally recommended that all the pool water circulate through the collectors every 8 - 12 hours.
This means if your pool is 15,000 gallons then the flow rate should be between about 5,000 gallons per hour and 7,500 gallons per hour (multiply swimming pool volume by 0.66 and 0.5 and this will give you correct solar pool heater flow rate)
You can work out the volume of your pool as follows to specify solar pool heater flow rates
Measure swimming pool in feet
Length x width x depth (average) x 7.49 = US Gallons
Length x width x depth (average) x 6.25 = Imperial (UK) Gallons
Measure swimming pool in metres
Measure swimming pool in metres
Length x width x depth (average) x 1000 = Litres
How big should a solar collector be for my solar pool heater?
There is a not a single answer to this question and to be accurate a series of complex calculations have to be made ... however don't be too concerned about this at this stage except to recognize that your solar pool heater size (surface area) will depend upon these main factors ...
- Hours of sunshine on average
- Size of swimming pool (ie volume of water)
- Flow rate of water through the solar pool heater
- Temperature you like to swim in .... a nice temperature is between 26 and 28 degrees Centigrade or between 78 and 84 Fahrenheit
- Ambient temperature ... the lower this is the more heat will
be required to warm the same amount of water
Whether you use a swimming pool cover or not ... this for example will reduce losses of heat during the night and means you could get away with a smaller solar pool heater - The generally accepted rule of thumb is that the solar pool heater's surface area should be approx 50% of the swimming pool's surface area
what the north carolina solar center suggests
Collectors for solar pool heaters can be mounted on roofs or in any other location near the pool that provides proper exposure, orientation, and tilt towards the sun. The optimum solar pool heater's collector orientation is south, but west-facing orientations are satisfactory for pool heating as long as the collector area of the solar pool heater is increased to a minimum of 75% of the pool surface area rather than the average rule of thumb of about half of swimming pool's surface area
East facing (ie in northern hemisphere) orientations are marginal.
The tilt of the collector for solar pool heaters is just as important as the orientation. To receive maximum solar radiation, collectors should be perpendicular to the sun’s rays. For primarily summer heating of solar pool heaters, the tilt should be equal to your latitude minus 10 to 15 degrees. In situations where it is desirable to install the solar pool heater collector horizontally, such as on a flat roof, the collector area should be increased to 75% of the pool surface area.