Water Temp

[PoolDoc]

I live in San Antonio and my pool is in direct sunlight. During the summer the water gets up to 96 degrees which is way to warm to enjoy. Any recommendations on how to keep it cooler? I know they make a solar cover to keep it warmer, but do they make something to keep it cooler?

Hi jcpbnp;

Just to let you know, this probably should go into the Pool Ops section, so I'm going to move it there shortly.

Meanwhile, back to your regularly scheduled question:

1. Contrary to myths I periodically see on the net, ice won't work . . . unless you bring truckloads! A couple thousands of pounds of ice just doesn't have enough 'coolth' to remove all that heat in a 10,000+ gallon pool.
2. Reverse heat pumps could certainly work, but don't count on it, unless you confirm that function with the manufacturer for YOUR area, YOUR size pool, and YOUR heat pump.
3. Sprayers work, but how well depends on lots of variables. In dry air areas (AZ, NM, etc.) a sprayer can cool the pool a LOT, by evaporating a LOT of water. This in turn tends to concentrate the salts in from fill water that's already saline . . . and you are off and running toward a whole new set of problems. In wet air areas (FL, LA, MS), spraying during the day may not be too effective. But, high volume sprays at night, when the air is cooler can make a difference without evaporating much water.
4. Solar heaters -- really -- can also work, if you circulate the water at night, when temps are lower and there's no sun. They'll work best when night skies are clear, and if you can keep them from contact with heat storing surfaces like concrete or thick roofing.

But . . . there's little data on how to size the things that will work, so it's really hard to predict how well they will work. Your best bet is probably to start with things that are cheap and easy (like night operation of fountains quick connected to pool inlets) and test for yourself.

Of course, if you do, I'd love it if you could report results back here.

Ben

[duraleigh]

Here's food for thought:

I intend to divert my return water through a "cooling field". (You gotta' have a lot of room to do this) Once I can find a deal on 700' of 3/4" copper pipe, I'm gonna make a manifold and take my 2" return line into 7 - 100' runs of 3/4" copper. I'll bury those 7 pipes about 6" apart and 4' deep. By the time my return water makes it's journey through the copper and comes back together (joining my regular return lines), I'm hoping my return water temp will be around 80 degrees. The only thing I can't quite get a handle on is how well the surrounding soil will dissipate the heat given off by the copper pipes. If I cannot dissipate the heat quickly enough into the surrounding soil, my returning water temp will not get low enough to effectively lower the temp of the whole pool.

This experiment is waaaay too pricey with new pipe. I've been looking on the net and locally for something surplus....nothing yet...I'll post the results when I find the pipe!!

[waterbear]

Copper pipe? Aren't you afraid of the possiblility of introducing copper into your pool?

[duraleigh]

Copper pipe? Aren't you afraid of the possiblility of introducing copper into your pool?

Nope! Just as if I had a pool heater, I watch my pH.

Dave S.

[CarlD]

Running solar panels at night is nice and simple. They act like a car radiator.

[rdietman]

wouldnt pushing the water through all that small diameter pipe cause some pump head problems??????

[duraleigh]

wouldnt pushing the water through all that small diameter pipe cause some pump head problems??????

If you don't use enough of them, yes. The seven 3/4" pipes is slightly more cubic volume than the 2" pipe feeding them.

I need the multiple pipes for the increased soil contact for heat dissapation and am willing to trade off a little TDH to get it. I'm thinking it will add about 2-4psi max to my pressure.

Dave S.

[dalparadise]

I live in Houston and have similar water temp issues, as you might imagine.

The best thing I've found is to avoid running your pump at the hottest point of the day (or at least when the sun is directly overhead) -- 12-3pm, or so. Note that radiant heat from the sun is much more effective in heating your pool water than air temp. So, even though it's usually hottest here in Texas around 5pm, or so, the sun is not directly overhead.

My pool is on the north side of my house, so the sun tracks across it all day long in summer. I got 94 degrees every day in July.

Toward the end of summer, I planted some 8' Mexican fan palms on the western edge of the pool to cast long shadows after 5pm. That has helped.

With night filtering and some shade, I'm thinking I'll get 91 degrees this summer -- which is enjoyable for me.

Good luck!

[shippy1973]

I live in Houston and have similar water temp issues, as you might imagine.

The best thing I've found is to avoid running your pump at the hottest point of the day (or at least when the sun is directly overhead) -- 12-3pm, or so. Note that radiant heat from the sun is much more effective in heating your pool water than air temp. So, even though it's usually hottest here in Texas around 5pm, or so, the sun is not directly overhead.

My pool is on the north side of my house, so the sun tracks across it all day long in summer. I got 94 degrees every day in July.

Toward the end of summer, I planted some 8' Mexican fan palms on the western edge of the pool to cast long shadows after 5pm. That has helped.

With night filtering and some shade, I'm thinking I'll get 91 degrees this summer -- which is enjoyable for me.

Good luck!

Ok... I am resurrecting this older thread because I am in the same spot as the original poster. I, too, live in SA and today I looked and my temp was already 86. So... you are saying that I should run the pump from about 8AM-12PM and have it shut off? I usually add my bleach at about 8PM and the pump shuts off at 12AM so I could turn it back on then. I would get my 8 hours a day and miss the hottest part. Does that sounds reasonable or is that too long between? This is not a HUGE deal but I don't want 95 degree water by the end of the week (suppose to be high 90s for the next 4-5 days...)

[estonb]

I am in S. Texas - same problem.

I've often thought about what adding dry ice the pool water would do to it. It is certainly cold enough, but I can't find anything that tells me what (if any) chemical changes it might make to the water.

Any ideas?