No, no, no! We get this all the time. People decide that it would be better if they let water heat up more before returning it back to the pool. Generally speaking, the opposite is true. Solar pool heating panels work most efficiently when the difference between the panel surface temperature and the pool water is greater. As the pool water temperature approaches the solar panel temperature, the rate of heating decreases, making the panel less efficient. Most solar pool heating panel systems require an absolute minimum of 2 gallons per minute (GPM) per panel. Three to five GPM is a better target, depending on panel size and type. You won’t get much additional heating performance from higher flow rates.
Solar pool heating panels add a small amount of pressure to a pool system, which results in a small reduction if flow rate circulating your pool water. This reduction is negligible. This does not cause damage to your pump, and does not require more electricity. Learn why here.
This is an oldie, but goodie. The concept here is that adding a solar pool heater to your existing pool equipment will burn up your pump because of all the extra pressure. Most of the time it’s total nonsense, told by someone who doesn’t know what they are talking about or unsure if it will work. If your pool equipment is already running near the pump’s maximum head pressure, then adding a solar pool heater could push it “over the edge” and stop water flow altogether. High head pressures result from poorly designed pools or improper operation. Most pools, especially newer ones, are built to efficiently let water flow through the piping and circulate water in your pool. The pump operates nowhere near it’s limits. Pumps burn up and die prematurely when they are “dead-headed” or near that point, meaning no water is flowing because there is too much pressure in the system. The water in the pump housing gets really hot, burning out seals. A solar pool heating system typically adds just 3-5 PSI to the operating pressure of your system. As a rule of thumb, if your filter pressure gauge reads less than 20 PSI, you will probably be just fine. Anything over 20 PSI requires a little more investigation. Often, high system pressures are caused by clogged filters. As always, consulting a solar professional is the best way to prevent issues with your existing pool pump.
Note that some pools do operate at higher pressures purposely to allow in-floor cleaners to work properly.
A properly sized and installed solar pool heating system can raise the temperature of your pool by 10-15 ºF above that of an unheated pool. The size of your system and its relation to the size of your pool is very important. Solar pool heating systems efficiently heat pool water to temperatures every day that would cost a fortune with an electric heat pump or gas heater.
The initial cost of a solar pool heater is similar to that of a quality electric heat pump or gas heater, and often less costly if you need new electrical circuits or gas storage. Solar pool heaters will operate for 10-20 years with no additional operational costs, unlike heat pumps and gas heaters that require costly electricity or fuel. Heat pumps and gas heaters are likely to need replacement at least twice in the lifespan of one solar pool heater, and require maintenance.
Solar pool heating systems use your existing pool filtration pump to circulate water through solar panels. There is no added electricity required to do this. The only exceptions are:
- Adding an automation system to control the on/off operation of your solar pool heater to control temperature. The amount of energy needed for an automation system costs pennies a day.
- If you have a variable speed pump, the pump will need to operate at a speed appropriate for solar pool heating. Automation systems easily balance the energy savings of variable speed pumps with heating performance. You never need to use more energy than necessary to pump water with a variable speed pump.
Solar pool heaters provide a gradual rise in the temperature of pools each day and over a period of days depending on the weather. This is not usually considered a disadvantage, because unlike other heat sources, a solar heated pool is warmer than an unheated pool every day of the year. You don’t have to wait for pool water to warm up after turning on your heater because it is “always on.” Electric heat pumps and gas heaters require planning ahead and must be turned on well before pool use to reach the same temperature that a solar pool heater reaches every day.