Cooling a swimming pool

[Peabody]

I have a pool in the back yard, and it has little shade. So at this time of year it gets too warm - 90 degrees or more. I would like to find a way to cool it down four or five degrees. There's a chiller, of course, but that's too expensive.

I've tried to figure out a way to shade it, but haven't come up with anything that wouldn't just blow away the first time the wind blows.

But I was at Home Despot the other day, and they sell 4x8 sheets of some kind of foam insulation which has foil on one side. And it occurred to me that just floating a half dozen sheets of that on the surface, foil side up, might do some good.

There would be opposing tendencies with this. By preventing some of the direct sunlight from reaching the water, the insulation would reduce the heating rate, but it would also tend to insulate the pool, thereby preventing the water from cooling by radiation and evaporation.

So, to get the maximum benefit, I would need to put the insulation on the pool only when it's in direct sun, and take it off at night. And of course I would remove the panels when someone wants to swim.

By a good margin, it's the sunlight that heats the water, not the air temperature. The pool has a surface area of about 550 sq ft, and six panels would be 192 sq ft, or 35%.

Does anyone have an educated guess, or even a gut feel, whether this might work or not? Or does anyone have any other ideas?

[jimmyDahGeek]

Backflush the pool to remove some water then run the hose into it with cold water.

[Rich]

Yes go to your local pool store and find one of those silly things that float in the middle of the pool and spray water up and out from the discharge of the pump. This aides in evaporation which is 90% of the heat loss from a pool.

Also ask your local pool person what they do in your area. My area I leave the solar cover off and all is well in time as I lose 5 degrees over night due to evap. and general cooling.

Good luck, Rich

[mm]

Why? Let them try something new and challenging. Call it polar icecap training.

[Steve Barker]

My only question is what's wrong with a 90 degree pool?. Makes for quite pleasent nite swimming.

steve

[Steve Barker]

You could lay a length of poly tubing 36- 48 inches under the ground and pump the water through that. Probably would take a thousand feet of it to do any noticible good though.

steve

[SteveB]

Try this. It's what I do in the hot hot summer. I leave the solar heater on, but circulate the water from eight PM to four AM. Going through the collectors definitely cools it down. Now, if you don't have collectors, your water will still be losing some heat to the outside air. Try it. It just might work.

Steve

[nicksanspam]

Greenhouse suppliers sell "shadecloth structures" for growing lettuce in summer sun, black mesh fabric suspended on posts...

Sounds inconvenient to remove, and they may waterlog over time.

This could work, or the fountain thing, or pumping water up over the coping or a nearby roof at night.

Nick

[hobbes]

Reminds me when I was at the Roadway Inn in Boise Idaho. It was Chirstmas time and snow all around. They had this indoor outdoor pool. The inside half was cut off just above the water by a roller shutter system. They kept the pool running and toasty warm by placing polystyrene puff bits, about half the size of a golf ball all over the outside part of he pool.

You could swim from the inside and emerge into the sub zero air outside through this "Polar Polystyrene Ice Cap".

This would help keep your pool cooler and keep the sun off it. Downside is you have all these polysyrene bits all over the place. It definately works though. I was at that hotel for 6 months ... so I got to know the pool and other features real well ....

best, Mike.

[Jerry]

If your pool has an aerator, run your pumps at night with the aerator turned on - always drops mine a few extra degrees.

Jerry

[Bill]

Great idea... you could buy some solar heaters in the north, rebadge them as "lunar coolers" and sell them in Arizona.

[gfretwell]

I paid a little extra and got the "combo" unit for here in Florida.

My controller decides whether to run at night or day, solar on or off, based on the water temp.

[SteveB]

I had been offered that add on when they installed the system. I didn't figure I would ever need it. If I ever get another, I'd buy the controller, and advise anyone else to do it.

There's no real work, other than resetting the clock. But, if you're like me, you forget for a month or two. Last time, the pool got up to 100. Automation can be your friend.

Steve

[Bob F]

It sounds like it could help. Set the pump up to flow water over the cover at night for cooling as needed.

The foam will probably get waterlogged over time. They also make reflective mylar "bubble wrap" for reflective barriers that might work more like a standard pool cover.

Bob

[giroup01]

Install a swimming pool fountain and use it at night.

[Jmiller]

I have an idea I plan to test soon. My pool is too warm too.

I am going to take an old car radiator, connect it to a smaller pump. Attach a box fan to the radiator. Run it at night when the ambient temperature is cooler. It is basically the same as those $2000+ expensive units.

[Keith Stelter]

You don't even need to do that. Just tee off of your discharge line with a

30 or 40 ft pool vacuum hose laid out >> I have a pool in the back yard, and it has little shade. So at this

[Peabody]

That's exactly what I need. At least I think it is. In theory, it would be the exact opposite of your typical pool thermal blanket. And it would work just like the 4x8 sheets, but should be cheaper, and a lot easier to deal with.

I'm still not sure about the thermal aspect of this, but my gut feel is that it blocks more radiation from coming in than from going out, which is what I need.

Where would you go to find the reflective bubble wrap? I assume this would not be a Home Depot kinda thing.

Well, here's an alternative. A lot more money, but nothing to put on and take off. Actually, a pretty nifty idea, I think:

[Steve Barker]

just be sure you keep that PH in check with that brass/copper in the system. It'll make a real nasty stain on the vinyl if it gets too low and starts transferring metal.

steve

[spammer]

Throw in a few bags or blocks of ice before hopping in.