Is there a concensus on finish color & heat gain?

[glitter&guns]

Sorry- I hate to ask yet another question, but just when I think I have all my ducks in a row someone scares the whole flock.

Cement guy that subs for pool co was here to look over some work that will need to be done during pool remodel. I talked about colors for cement work and showed him inspiration pool pictures. He really questioned my pool color choice. I selected a medium grey finish for the pool. He insists that I will have a temperature increase with that color. That is something that I really don't want. So I sat down to do some reading and now my head hurts when I think about this.

The pool is in partial shade almost all day with maybe 2 hours in the mid/late afternoon with no shade. It is 3'at shallow end (no beach entry) and 8.5 feet at deep end (maybe 9'). It is Texas so there is absolutely no escaping the wind, but the pool sits below grade on 2.5 sides, so the wind is significantly decreased MOST of the time. The exception is a north wind and we really don't get those in the summer here. I have surrounded the pool with grass rather than cement in a effort not to absorb additional heat in that area.

I really like the look of the darker water and thought that I was secure in the idea that pool temperature would not be raised. Cement guy insists it will be. My reading across the internet presents arguments both for raised temps and against raised temps. I trust the advice I get here more than anywhere else, so what say you? I have until the end of this week to change my mind.

 

[mrcarcrazy]

Darker will be warmer. the question is how much warmer. I can say that a family member here in Odessa, TX has a very dark blue quartz plaster pool. His water isn't ever unpleasantly warm. His is also full sun. I'm not an expert, but based on this one single experience I wouldn't worry about the temp increase. I've been over there on 100+ days and the water felt great.

Edit: cbink brought up a good point. This pool I'm referring to is 4.5' deep.

 

[cbink]

I think it's a really hard question to answer because there are so many factors that go into the sun heating a pool and the effect the color of the finish will have that you'll struggle to get a truly precise answer.

My thoughts are that the difference will be fairly negligible, especially given the depth of the deep end and that the pool will be in the shade most of the day. I would expect the difference to be more pronounced in a pool that sits in the sun all day long and is of a sports pool type or is relatively shallow.

 

[joepaiii]

I just found this rather long blog post http://scienceofdoom.com/2010/10/06/does-back-radiation-heat-the-ocean-part-one/ that confirmed what I suspected. At 2m or sea water only 14% of the energy in solar radiation remains. Since a pool has many sections that are that deep you will get little heating effect of the water at that depth.

Since some pools have large shallow areas you may get some extra heating of the water. Note that I say water, I haven't mentioned the color of the plaster. I don't believe that the color of the pool shell would make a significant difference to the temp of the water. The shell is an extremely large thermal mass against an even larger on (earth) that is at a relatively cons tent temp. I think actually changing the temp of that in 3 feet of water would be very tough.

Anyway this is a question that comes up all the time and people worry about it. I believe if it were truly and issue there wouldn't be black options in southern climates.

 

[RobbieH]

But we are all about options. Just because something isn't a good idea doesn't mean the option to buy it won't be there, unless you live in California . You can have a black roof put on a house in Texas too.

 

[doobs41378]

We have a black liner and I do not think it warms it up alot more, that being said I do not really have anything to compare it to as it's my only pool : )

 

[Patrick_B]

Here in the hot Tx Sun it makes a pretty big difference. I think even white pools absorb something like 60% or more of the Sun's energy.

 

[joepaiii]

Here in the hot Tx Sun it makes a pretty big difference. I think even white pools absorb something like 60% or more of the Sun's energy.

How does it make a difference? Do you have examples where the same pool had two different finishes and was measured much hotter with the darker finish? It is so hard to make any kind of comparison about temperature of two different pools that any comparison is really worthless. Even with the same pool I can think of about 1/2 a dozen variables that could make the comparison invalid. About all you can do is look at the physics of heat transfer which is what the blog post I sited does and you can infer some things about heating effects in bodies of water.

I have a white pool in Texas and it hits 94 degrees in the hottest parts of summer. I really don't see it getting much hotter than that. I guess that is one way to get an idea is to ask people what their high temps are and then query location, average depth of pool and pool color.

 

[pooldv]

We have a black pebble sheen finish play pool that gets full sun less than 2 hours and some amount of shade to full shade early and late in the day. Pool never got above low 90s last summer and we often ran our solar panels (5 48sf panels) during summer to warm the water more after rain or cloudy days. We prefer our water 85 and up. We are in the DFW area. I know another person with a full shade black bot m pool and they can't get their pool out of the 80s ever.

 

[glitter&guns]

Thank you all so very much for your help. I am going to leave the finish mid grey as I originally selected. While there are some people here who believe it would make a difference, I have to believe that the science of the water & the heat sink of the earth around the pool, coupled with evaporation is going to hold it at a reasonably low temperature. Pooldv, your evidence is especially convincing that I am not going to be boiling the kids like frogs in a science experiment. My pool stays cooler (shade) than the HOA pool (full sun) that I had access to when I first moved to the area. Both are about the same shade of blue at the current time.

It may be a mistake, but one that I should only have to live with for 7-10 years until it is time for the next refinish - I guess that is one of the good things about doing actual plaster as opposed to one of the upgraded finishes - I know it is going to need redone in a few years. Thanks everyone for your input. I do feel better. Usually I am so sure of my decisions, but for some reason this pool is just making me second guess myself over everything.

 

[JasonLion]

There is no question, a darker pool finish will warm the water more than a light pool finish. The science on that is totally straightforward. The only open question is how much. Anecdotal evidence suggests numbers around five degrees, comparing very light finishes to very dark finishes, though that is far from settled and could easily be higher or lower.

 

[glitter&guns]

OK - so maybe there is a temperature difference. Assuming that I might need to counteract that, here is another temperature question - would a water feature of some sort drop the temperature? Evaporation causes temperature drop in remaining water (if I am remembering high school science correctly), so would a simple spray of water counteract the heat? I have seen retrofit type sprayers that can be attached to the return jets to make a simple water feature. Would that drop the temperature during the summer?

 

[RobbieH]

I use a homemade sprayer to lower my pool's temperature overnight. It is effective. Note it does raise pH, I have to add more acid than normal when using my sprayers.

 

[glitter&guns]

I use a homemade sprayer to lower my pool's temperature overnight. It is effective. Note it does raise pH, I have to add more acid than normal when using my sprayers.

Home made sprayer? How does one create a homemade sprayer if you don't mind sharing that info.

 

[RobbieH]

Essentially you get the PVC fittings to attach a line to a return (or lines to returns) then go up out of the water and drill several small holes to spray the return water through the air and into the pool.

http://www.troublefreepool.com/thre...-How-To-quot-for-a-quick-amp-easy-pool-cooler

Run it at night for best effect.

There are lots more on here too, just have to be creative with your search terms.

 

[MiaOKC]

We are going with a mid-gray plaster in our mostly-sun pool renovation to try to warm it up. We like it warmer, and it was often too chilly for me last year. The prior year, when we had all 100s all summer (it seemed) it was perfect.

We think it will be easier to add an aerator (like the fountain described above) than to add solar heat, so we're gambling. If we have to do nothing, great, but if we have to do one or the other, we expect it.

 

[glitter&guns]

Essentially you get the PVC fittings to attach a line to a return (or lines to returns) then go up out of the water and drill several small holes to spray the return water through the air and into the pool.

http://www.troublefreepool.com/thre...-How-To-quot-for-a-quick-amp-easy-pool-cooler

Run it at night for best effect.

There are lots more on here too, just have to be creative with your search terms.

How did I not know about this??? Thank you so much RobbieH! My pool was only overly warm a few days last year (I didn't mind it, but my girls complained that it was like swimming in a bath tub). It would be nice to be able to hook this up for a couple of weeks out of the summer. With the darker plaster I may need it. Now I am feeling 100% better about my color choice. Thank you. Plus, the neighbors can be jealous that my pool has big ol redneck stick thing. lol! Those are rare around here! Y'al really are the best.

 

[RobbieH]

No shortage of redneck engineering in Texas!

 

[glitter&guns]

No shortage of redneck engineering in Texas!

It is my favorite! The poor folks at Lowe's/Home Depot probably have my picture in the back of the store as a warning. I go in with this conversation starter A LOT: "So, I had this idea that there has to be some way to do this thing that really doesn't ever get done, but in my case it would be great. I have a picture of the thing that I need to attach it to, but it needs to look decent when I am done and it can't have any sharp edges - which department should I start in?". They love me there... surely that is the emotion they feel when I bring them such interesting challenges. Although last time the guy that helped me asked me if I ever actually DO these things after I buy parts. I was happy to pull up my last "you might be a redneck if" project and prove to him that I actually do them. lol! Actually, I haven't harassed the folks in the plumbing department. This would give me someone new to talk to! lol!