solar cover on/off for best heating?

[tenax]

not sure it warms up faster for me with a cover on..more so, saving heat due to evaporation...and cools off a lot less definitely with a cover on.

[PhantomAndy]

My experience in Kentucky:

When the air temperature is going to be above the water temperature, and little to no wind, I get more heat gain without my solar cover on. The higher the air temp, the less of a problem the winds are, or so it seems for me.

When the air temperature is below the water temperature, it's usually better on.

Of course, if you are trying to maintain your water temp, you should always have it covered when not in use overnight.

Bottom line is that when the air temperature is below your water temperature you will experience much faster heat loss via evaporation than when it is at or above the water temperature. Wind and humidity obviously play parts as well (wind more so than humidity unless you have near 100% humidities).

I'm in the process of collecting some real numbers since our weather pattern for the past few days and into the coming week like a broken record. If I'm able to establish any solid numbers that indicate 'the truth' I'll be sure to submit my results here.

This particular topic is very hotly (no pun intended) debated in any pool forum. I'm wondering if Mythbusters would consider putting this one to the test in some scientifically controlled conditions? I think I'll send an e-mail to Adam and Jaime! They can use my pool as long as they send Kari to help out

[ePoolUser]

Our water was 78F at 12" when I opened the pool 2 weeks ago.

Over the past week, the weather has been generally calm with sunny warm days, 85-88F and cool nights, 55-65F. With the solar cover on 24/7*, the first 3-4" of water (at the surface) have hit a hot 95F repeatedly (pump off all day). At 12" the temp is 84, at 2' the temp is 80. *We remove the cover and swim for about an hour every evening and replace the cover.

I can't imagine the surface getting so hot without the cover. Would the water warm more evenly and deeper with direct sun rays? Idunno.

I am in the Nashville, TN area. If you are in this area without a solar cover, what are your temps?
27' AG

Steve

[ivyleager]

How about this test? It's not scientific, and has tons of flaws.

Lay on the ground on a sunny day.....how hot do you feel?

Lay on the ground on a sunny day with the solar cover over you....how hot do you feel? (heck, put a towel over you and you're still hotter).

My lawn burned last year from leaving the solar cover on the grass for 1.5 hours while I cleaned it off due to bugs, bird bombs, dirt, etc. My lawn doesn't burn from just the sun.

IMHO, the solar cover traps the heat and reduces heat loss.

BTW, yard totally recovered.

CaryB
Go Sens Go!

[CarlD]

With it on, period.

[poolbee]

Wow. I guess there is no definative answer. I am in Western NY-Buffalo area. My pool is in direct sun morning til night and we're in for a few cloudless days so I want to take advantage. I am just concerned about getting my water up to a comfortable temp. It was 70 yesterday. My youngest couldn't stand it any more and went in! Way to cold for me. We always have it on at night. Just wasn't sure if on/off during day was better. I have a heater, but would rather not pay to heat if I don't have to.

[Jeffski]

You could heat the water and then just use the cover to keep it hot.