Keeping Heat In

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
I am losing a lot of "heat" during the evenings. During the day our water temps get up to about 82 deg (if sunny and air temp is 75 or so). At night we put on the solar cover and the intex cover that came with the pool. By the morning, I have lost anywhere from 8-12 degrees!! I do not have the money to buy a pool heater so that is out of the question.

I thought I read something about using foam board on the water surface to help insulate in the evenings. If so, I would try that and put it on after the solar cover and before the intex cover.

Does anyone have any suggestions?
 

MattE71

Well-known member
Jun 7, 2013
79
My Intex cover was in the garbage after 30 days as it broke (Junk). I just use a clear solar cover on a reel to keep the cover off the grass.

The foam boards that you're referring to would be when you set your pool on top of the foam boards (on set up). This really helps with the heat loss to the ground. I also use the Eco Saver solar panels which work really well. Hope that helps!?
 

Casey

TFP Expert
LifeTime Supporter
Apr 16, 2007
11,543
SW PA
I've never read of someone putting the foam boards on top of the solar cover or any variation you can think of.
 

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
I've never read of someone putting the foam boards on top of the solar cover or any variation you can think of.
Read the last entry in this conversation. This is where I got the idea.
http://www.troublefreepool.com/threads/68581-Insulating-extern-of-AG-pool

Also, has anyone ever tried using black bubble wrap as the "solar cover" for the daytime? I thought it might really generate a lot of heat to put into the water. Living in MN we are only get our pool up to 82 (which isn't bad) but when it is 70-75 deg outside with a wind we are shivering. So how about black bubble wrap?
 

Mandolina

Well-known member
Apr 18, 2014
67
Los Angeles USA
We have a Clear Diamond solar cover, here is the description from Amazon.com. "When seeking the best in passive solar heating for your swimming pool, look no further than this Clear Diamond solar cover. The air pockets in solar covers work to trap the sun's heat and transfer it to your pool. This cover's diamond formation of air pockets works to provide the maximum amount of heat into your pool's water by reducing the amount of space between air pockets, meaning more water receives solar heat. The clear heavy gauge material has been tested to provide the best solar absorption for solar covers. By combining these two elements, you have the best possible form of providing free solar heat for your 16 foot round swimming pool. 8 Year Warranty / 2 Year Full" It's attached to a Solar Roller stick which makes it completely removable.
 

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
Its above ground. You need to insulate the walls somehow. That's where your loss is.
Any ideas how to "insulate the walls"...do you think bubble wrap would work to wrap it all around the sides of the pool? I was even thinking of using black bubble wrap to transfer the sun to the sides of the pool and then the bubbles would be the insulation at night. Thoughts anyone?
 

DigbyAllen

LifeTime Supporter
Aug 9, 2012
132
Westchester, NY
I think part of your problem is your location -- Northern MN. What is your typical overnight temperature?

I have the same pool and I live in southern NY. It has been a very cool summer with nighttime temperatures only in the high 50's and low 60's. Even with the solar cover I typically lose 3-4 degrees overnight. Obviously the cooler it is, the more heat loss. We had a few hot days early in the summer and my pool water was in the high 80's. It's now closer to 80.

But the nice thing about a small pool is I can just as easily make that temperature loss up, and more, on a hot sunny day. I have one Ecosaver solar panel which helps a little. On a sunny day it adds about 2 degrees to the water running through it.
 

kodos

New member
Aug 1, 2014
2
Scottsdale, AZ
Any ideas how to "insulate the walls"...do you think bubble wrap would work to wrap it all around the sides of the pool? I was even thinking of using black bubble wrap to transfer the sun to the sides of the pool and then the bubbles would be the insulation at night. Thoughts anyone?
Bubble wrap would not be durable enough.

What could work are rigid Styrofoam boards. You can buy these as 4 x 8 foot sheets (and other sizes) at big box home improvement stores. They also come in various thicknesses - which is one factor in determining the R-factor of the insulation (the other is the nature of the Styrofoam). In general, you'll see 3 colors: white, blue, and pink - which are good, better, best. R-values from about 6 to 10. Some may be available with one side faced with a heavy paper or foil cover. However, these are not normally exposed to the weather - a typical practice is to cover them with chicken wire, then with stucco. So a big part of your decision is how you could work this product into your pool design and end up with an attractive result.

I did see - and experience - once a heated in-ground pool in northern Michigan that kept the heat in with thick, floating foam strips. These were probably 3-4 inches thick and more of the consistency of what you'd see in a swimming kick board.
 

DarrelB

Well-known member
Jul 22, 2014
429
Oakbank, Canada
Put it this way............the foam boards would not hurt, could only help, Now as too how much, not sure, but must be worth a few degrees for sure. Saying that now, I am sure there is some heat that would be lost no matter what you did. The idea is to minimize it.
I live in Manitoba, just above you pretty much, so we have similar temps, highs and lows. Some times my pool is a nice 84 degrees, and then when cool weather sets in, back down to 75 or even lower.


I am losing a lot of "heat" during the evenings. During the day our water temps get up to about 82 deg (if sunny and air temp is 75 or so). At night we put on the solar cover and the intex cover that came with the pool. By the morning, I have lost anywhere from 8-12 degrees!! I do not have the money to buy a pool heater so that is out of the question.

I thought I read something about using foam board on the water surface to help insulate in the evenings. If so, I would try that and put it on after the solar cover and before the intex cover.

Does anyone have any suggestions?
 

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
As stated, my nighttime temps this time of year are 50-60 on average. Here is what I finished this evening. I fitted 2" pink foam boards around the surface of the pool. The solar cover is against the water. Then the "intex" cover. Finally the pieces of the foam board (put together like pieces of a puzzle) - so three layers after the surface of the water. The solar cover and foam board is for the insulation. The intex cover is to keep debris out and keep the foam board from making contact with pool water. Hopefully this will pretty much "eliminate" any heat loss out the top (I'm sure there will be some, minimizing is the key).

Now I need to figure out how to insulate the sides?? To me, foam board is out of the question. The curvature of the pool would make cutting and piecing the board way to time consuming, plus foam board is expensive and the time it takes to put it together, plus cost, isn't worth finding if it even helps.

As far as what it looks like...I really don't care. Right now I have black sheeting along the south side of the pool to collect solar heat and transfer that heat to the sides of the pool. Aesthetics is about the last thing I'm worried about if I can get a warm pool.

I'm curious, Kodos, why you think bubble wrap would not be durable enough? Aren't all solar covers simply bubble wrap in clear or blue?
 

csk158

Active member
Jun 1, 2014
27
mi
If you dont care about looks and if you could find something to go over the top. What about spray foam insulation. Just a thought not sure if it would work.
 
Jun 23, 2014
19
Central MN
Hi there, I'm in central MN and as a first time pool owner it has been a terrible summer for getting my pool to warm up! My regular cover has been doing a pretty good job of keeping in the temps at night but when I'm only getting to 83 for an outdoor temp and it's not even that sunny it's a pain getting the pool temp up! Next year I will definitely invest in a good solar cover!

No onto your foam on the top ? I will say that when I worked for a hotel in Maine they had an outdoor hot tub. It was available year round but at night or on off peak hours they put down 4" foam cut to size in 4-5 sections over the solar cover that extended over the edges of the spa.It worked very well.

Good luck!
 

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
Last night, as I described above, we fitted the 2" foam board on the surface, with the solar cover and intex cover. When we put it on the water the temp was 82. Nighttime temps dropped to 55. In the morning the pool was 80 deg...so it seems like the foam worked and saved us at least 2 deg (some nights water temp dropped down to 74 after being 82 during the day -sp it may have saved us 8 deg). This morning is the warmest our pool has been after a cool evening.

Our experiment today is to take off all covering, run the pump, and see what the temp gets to. Forecast is full sun with a high of 80. Right now pool temp is 81 throughout.

Yes, I know, I have too much time on my hands!
 

DarrelB

Well-known member
Jul 22, 2014
429
Oakbank, Canada
Another option is maybe wrapping the pool walls in a black plastic shipping wrap. Comes on a roll about 24" wide buy a few hundred feet long. About $10 a roll from a local shipping product warehouse. You could just wrap the pool in black plastic wrap if your looking at doing something with the walls as well.
 

Kiss4aFrog

LifeTime Supporter
TFP Guide
May 22, 2013
2,740
Hudson, WI
Also, has anyone ever tried using black bubble wrap as the "solar cover" for the daytime?
Everything I've read in preparation of buying my new cover this year said that CLEAR was the best for capturing the most heat during the day. That would tend to indicate black wouldn't be a good choice.
 

TrustJesus

Well-known member
Jul 17, 2014
51
Northern Minnesota
Another option is maybe wrapping the pool walls in a black plastic shipping wrap. Comes on a roll about 24" wide buy a few hundred feet long. About $10 a roll from a local shipping product warehouse. You could just wrap the pool in black plastic wrap if your looking at doing something with the walls as well.
Do you mean like bubble wrap? That is something I considered, in black, to help absorb solar heat and transfer to sides of pool during the day. Then the "bubble" would be the insulation. Could you link the product you mentioned?