Equipment in direct sun increase water temperature?

cjs

LifeTime Supporter
Jul 13, 2014
35
Cypress, TX
I'm in Houston and have tried throughout the years to cool my pool with evaporative cooling fountains and such.. It's too humid here and just doesn't work... Doesn't matter time of day.

This past weekend, I decided to build a frame from PVC and use a tarp to shade my pool equipment. My equipment pad is on the west side of my house and gets about 4-6 hours of direct afternoon sun. My pool itself gets morning sun, but begins to be shaded about 11:00 am and is fully shaded by 4pm.

My thought is, just as the water passes through a heater, the sun works as a heater (albeit to a much lesser degree) as the water goes through the filter, pumps, and pipes. Immediately after putting the tarp on this weekend, the temperature reading (aqua logic system) dropped by 2-3 degrees within 10 minutes. This suggests that the water was heating that 2-3 degrees at the equipment and cycling back to the pool.. Just like with a heater... Thus gradually heating the pool throughout the afternoon.

The temperature sensor is mounted in the pipe, but I'm assuming that it isn't affected by elements outside the water pipe.

So, any opinions on if this will have the desired effect? 2-3 degrees can make wire a difference (92 vs 89 degrees).
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,932
San Dimas, CA (LA County)
Question: was the pump on the whole time?

My pump and filter sit in full sun. I've noticed that on hot days, when the pump kicks on, the temperature display on the heater shows high. Then after a few minutes, as the thirty gallons (or whatever is in the filter) of solar-heated water mixes and exits the filter, the display shows cooler. You can see it drop over time. I don't think the equipment adds much heat overall to my pool, but that captive water sitting in the filter all day certainly heats up.
 

cjs

LifeTime Supporter
Jul 13, 2014
35
Cypress, TX
Yes, pump starts running about 11:00 am, which is before sun hits equipment. That's also when ambient temperature is still near or below water temp.. So that's not an issue for me.
 

phonedave

Well-known member
May 30, 2012
744
Montville NJ
The impact of the sun on your filter as compared to your pool temp is minuscule.

Search for threads on DIY solar heaters. People have calculated the total temperature rise from homemade solar heaters consisting of 100's for feet of black tubing in direct sun with water circulating through them multiple hours per day. The results are basically no discernible temperature rise. The heat coming from your filter sitting in the sub is no different.
 

guinness

Well-known member
May 3, 2019
553
California
See the following thread about temp sensor accuracy.

 

rphpool

Well-known member
Mar 4, 2015
691
Sugar Land , TX
I have a shade sail over my equipment. I noticed everything was getting real hot. I would think over time sun might damage pvc pipe and other equipment. Plus it keeps my chlorine tank cool!