Solar Cover in SWFL

Poolbill

Member
May 9, 2015
8
Ft Myers fl
Hi all, I am in SWFL. I hear my people pool all winter with a electric heat pump only. I keep it covered w a 16mil blanket to retain heat. I am wondering how to decide when to stop using the cover. Are there any calculations or rules of thumb? The outside temp is starting to warm. Thanks.
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,703
Sydney, NSW, Australia
Nice to meet you via TFP :)

It's a bit of a judgement call, but if it's full sun with sun high in the sky, and not too windy, you gain more heat from the sun than the heat you lose to evaporation.

You can get a feel for it by trying it with and without the cover for few days each under reasonably similar weather conditions. If you record your morning and evening temps, with the heat pump either running 24/7 or turned off, you'll get a feel for what works.
 

BasicTek

Bronze Supporter
Oct 9, 2016
867
Lake Mary, FL
It's the overnight lows that will have the most affect on the pool temp, you can use a tool like weather underground history to get an idea (February average low in FT myers is 60) so your current temps are about 5 above average. I use solar to warm up my pool and when the overnight lows stay above 65 I don't need a cover (last year that around April for me probably sooner for you). It's different with solar as I can't heat my pool as quickly as you, and I don't have much of a bill for heating it all day. The cover serves it's purpose mostly at night and I guess it's up to you how much you are willing to spend on heating it vs the pain of putting the cover on and off overnight...
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,703
Sydney, NSW, Australia
I was assuming you would always have the cover on when it's dark. Thanks for adding that, Tim. I thought it was about sunny day removal. Too frugal I am. Don't underestimate evaporation heat loss :)
 

BasicTek

Bronze Supporter
Oct 9, 2016
867
Lake Mary, FL
I was assuming you would always have the cover on when it's dark. Thanks for adding that, Tim. I thought it was about sunny day removal. Too frugal I am. Don't underestimate evaporation heat loss :)
I could be wrong too, but for me, I can't wait to get the cover off for the summer, that is a good point when it's not rainy season even if it is warm enough I ended up needing to fill my pool quite a bit last april as we were in a drought...
 

BasicTek

Bronze Supporter
Oct 9, 2016
867
Lake Mary, FL
On this topic, I left mine off this weekend and still managed to reach highs of 90, lows never below 84, but later this week we will be dropping to 70's during the day and low 50's overnight so the cover will be back. The air temp was mid to high 80's and mid to high 60's overnight.

If I had kept the cover on I could have had highs in around 94 and lows not lower than 88