Traditionally, pool owners have used natural gas, propane or electricity to heat their swimming pools but you can save energy costs by using a solar pool heater instead.
There are a number of factors to consider before you make the switch to solar heating. Here’s what you need to know about heating your swimming pool using the sun.
Things to Consider
- Solar energy is not as concentrated as other forms of heating, so the systems need to be large
- On a good day, a solar pool heating system may deliver the equivalent of five hours of heat.
However, because other heating systems only operate in a “spot heating” mode, the pool cools off in between times and requires more energy to bring the temperature back up. Solar heating operates in “maintenance” mode, meaning it is capable of raising the temperature of the pool to a comfortable level every day.
How a Solar Pool Heater Works
For residential swimming pools, solar heating works very simply. Normally, pool water passes through the pool’s filter before returning to the pool. With a solar heating system, the water is diverted and passes through solar collectors before being returned to the pool.
Solar collectors are black and so absorb the sun’s energy, which is then transferred to the pool water passing through them. Pool water flows into the bottom of the solar collectors and out the top. The majority of the time, the existing pool filter pump is all that is necessary to circulate the water through the solar collectors and return it to the pool.
A manual or electronic valve is used to divert the water to, or away from, the solar collectors. When the solar heating system is turned off, the water returns directly to the pool. When it is on, the water passes through the solar collectors and is returned to the pool warmer.
Proper Sizing
Attaining ideal results is not a simple matter of matching the size of your pool with the size of a solar heating system. Any solar pool heating system will be large. Solar collectors will need to be at least 50 percent of the pool’s surface area.
The following factors must be considered to properly size a solar pool heating system:
- Brand of solar collector (important)
- The size of the pool
- The desired pool temperature
- Pool shade
- Pool cover
- Solar collector shade, direction and angle
- Length of the swimming season
Long-Lasting Performance
Solar collectors must be properly installed if you want them to last. Most solar pool heating collectors have warranties in excess of 10 years and some have 15-year warranties or even lifetime warranties. Indeed, it’s not unusual for collectors to last over 15 years with very little maintenance. They may even outlast the shingles they’re installed on.
Some plastic collectors can be turned over to expose the opposite side, thereby doubling their useful life.