Insulation

[Cody87]

I'm wondering what would be better for insulating and heating my pool during the day. I've got this brown tarp on right now because it rained last night. Under the tarp and directly on the surface of the water is a bubble wrap solar cover with a very dark green tarp laying on top of it. I'm curious if leaving the brown tarp on would create some sort of warm area in between the two. Or if it would be better to take the brown tarp off during the day. Part of the reason I'm wondering if keeping the brown tarp on would help is because the surface covers have about an inch around the perimeter of the pool that doesn't cover the water. Any advice would be much appreciated.

 

[LFrankow]

I am a little south of you and just use a regular solar cover. Pretty sure multiple layers would help prevent evaporative heat loss a bit better then just one.
How big is your pool, and how many sq ft of collector are you running?
I have been getting pool temps near 90 f since mid may, just with my homemade 90 sq ft, which is about 20% of the surface area. I recently added another 80 sq ft of fafco panel, too soon to tell, but early signs have us smiling.

 

[Cody87]

278 square feet of solar mats. The pool is either 16 or 18 feet in diameter. My pool has been heating up, but what keeps killing me is the rain. It's nice and sunny for a week and then it drops to 15-18°C outside and rains for 2-3 days, then back to sunny. So that's why I put that brown tarp on with the centre raised to try and keep the cold rain water from getting in my pool. I'm not sure what else I'm doing wrong with getting this pool warm? It's getting quite aggravating. I'd LOVE 90°F water

 

[LFrankow]

Well 278 sq ft is over even the surface area of an 18 foot pool, recommended is solar surface = pool surface.
How are your mats piped? Series it looks like to me. What is your gpm rate? Timing how long it takes to fill an ice cream pail will tell you that number, the more the merrier.
Rain kills my pool temp also.

 

[Cody87]

I'll try and measure that today. Another thing I'm wondering is if I should just use the brown cover during the day on the surface of the water. Or should I still have the bubble layers under the brown cover. Is it possible that the layers all together end up to thick and I don't get much heat transfer? Obviously I'd be using the multiple layers at night to insulte the pool, I'm just wondering if I should do this on sunny days...

 

[Cody87]

I am a little south of you and just use a regular solar cover. Pretty sure multiple layers would help prevent evaporative heat loss a bit better then just one.
How big is your pool, and how many sq ft of collector are you running?
I have been getting pool temps near 90 f since mid may, just with my homemade 90 sq ft, which is about 20% of the surface area. I recently added another 80 sq ft of fafco panel, too soon to tell, but early signs have us smiling.

Where abouts do you live?

 

[Poolzzz]

He lives in Medicine Hat, it says so below his name just like yours says Edmonton.

As for your brown tarp during sunny days...suggest removing it...and the green one too...just leave your bubble wrap solar cover on during sunny days. A pool is a large solar collector that will absorb the suns radiation just like your solar panels provided the radiation reaches the pool. But your solid brown and green tarps are blocking all the suns radiation so the pool is absorbing very little energy. When the pool is not in direct sun then it is fine to load up on all the covers especially if you have dead air space in between each layer. Keeping the rain out is good, rain kills my temps too.

There is nothing wrong with having more solar panel area than pool surface area. The more the merrier for heating. But do you only run them when they are in direct sun? If they are operating when shaded they will be cooling the pool down not heating it (assuming your air temp in the shade is lower than the pool temp).

 

[lightmaster]

Here's a good image to explain it, courtesy of inyopools.com

 

[Cody87]

Awesome thanks I'll give that a try. What about on hot days having no cover at all? Or would the evaporative loss still warrant the use of the bubble wrap tarp?

 

[lightmaster]

With no cover, your pool will trend towards the average of the daily high and nightly low.
Also, a clear cover helps prevent evaporative lose and creates a greenhouse effect, allowing heat back in and tapping said heat inside.

 

[Cody87]

OK so even on a sunny day if I'm not in the pool keep the solar cover on?


I will add that it has always been covered unless it is in use. I'm just wondering if it will heat faster on a sunny day without the solar cover.

 

[Jezza]

The cover is most effective at preventing heat loss during the night.

Notwithstanding the daytime temperatures and intensity of the sun, you'll often find that it takes a few days to get the water to the maximum-cover on temperature with the cover being kept on over consecutive nights. If you leave the cover off even for one night, there will be a significant reduction in the temperature.

The cover does particularly help during the day with a reduction in evaporation and loss of FC.

 

[Cody87]

Thanks for the info. A while ago I was curious just how good the solar cover was at insulating overnight. I usually loose 3-4°F overnight with the cover on, but with it off I lost 10°F! I couldn't believe it!