Solar heater - could it also cool water a little?

[Watermom]

Several people here on the forum do run their water through their solar panels at night to try and cool the pool some.

[BigDave]

My solar panels were installed with a Gold-Line GL-235 controller which controlls a valve that directs the water to the panels when the panels are warmer than the water and the water is cooler than the temperature setpoint. It will also send water to the panels when the water is warmer than the setpoint and the panels are cooler.

[kckpool]

it won't cool nearly as good as it heats (btu-wise) but as long as the air temperature is cooler than the pool water temp the solar array will act somewhat like a car radiator. The greater the temperature difference the more effective the cooling will be.

[George in GA]

Many thanks for the opinions.

I'd guess that, just as copper or aluminum collectors would be more efficient in gaining solar energy they'd also be more efficient in shedding heat. Of course if I had access to a large number of truck radiators and fans....

But metal collectors would be far, far more expensive, and there'd be a greater risk of freeze damage as opposed to the plastic sort. Do any of you users out there have drain-down provisions for frosty nights, or are the collectors pitched so that they drain themselves?

[BigDave]

They should be installed to drain back. The GL-235 has a freeze protection option that will run water through the panels when temp gets near freezing to keep them from freezing and bursting.

[Sean OBrien]

Keep in mind, the glazing on the collector will work to prevent significant thermal losses at night.

If you have a large enough property with an area that is free from tree roots - you could use geo-cooling without too much of a problem. Ground temperature even a few feet below the surface are significantly cooler than air temperatures. You could use a thermostatically controlled valve to shunt water into a horizontal loop collector in order to cool the water before it goes back to the pool.

I am sure there is information around regarding the setup - and there isn't much difficult engineering in this particular application (nor extremely expensive materials). The biggest restriction would be the hole that you need. Horizontal loops are easy for DIY projects, you just need a large area to dig a 3 foot deep hole in. If that isn't an option - vertical loops work as well - though for those you usually need to hire a boring company to come in and drill your holes.