Lets put in a pool she said

[red-beard]

BTW - my pool in Houston is 93F today - Cooler than 102 air temp...

[flatbutt]

Just think of the energy needed to drop thousands of gallons by a few degrees.

[masraum]

Originally Posted by Paul T

My wife sets ours to 90 on purpose! Still refreshing on a hot day though…and I find I’m more apt to go night swimming when it’s nice and warm, so I don’t mind. We have a limited pool season here in PA, so I don’t mind spending $$ to heat for a few months.

My old boss from my old team moved from NY to Plano. He's got a pool. He told me last year that he wants the pool to be 95º. Sounds crazy to me. Of course, I think the temps in the center of Texas have been in the 97-107º range lately, so 95º might not feel horrible. But I suspect 82-85º would be much, much better.

[masraum]

Originally Posted by flatbutt

Just think of the energy needed to drop thousands of gallons by a few degrees.

30,000 gallons 85º to 95º takes 733.6 Kwh (equal to 2640954377J / 628798661cal / 733599Wh / 2503141 btu). IIRC, 10º∆ is the same whether it's + or -.

[masraum]

I would assume that if you had a solar heater, that it would work as a cooler if you ran it at night or when the sun was down. My mom's old pool was solar heated and was basically just a black plastic radiator on the roof. I think running that at night would cool the pool off if you had one like that.

[red-beard]

Evap cooling works great. 965 BTU per pound or 8060 per gallon. In my pool, about 25 gallons per degree F

[john70t]

Originally Posted by 911 Rod

I found most people like a warm pool. Me not so much. You actually sweat it a warm pool.

Dude. OMG. Thumbsdown. Nononononono. Internet negative reaction emoji repeated.

There is a *prized* warm-water salt lap pool around here in Michigan.
With a higher-temp Jacuzzi to boot.
The very best for physical rehab.

People will always obtain something great, available to only few, served on golden platter with bended knee, and want something different...

[red-beard]

Honestly, even at 93, it keeps you cool when the air temp is 102

[masraum]

Originally Posted by red-beard

Honestly, even at 93, it keeps you cool when the air temp is 102

Especially if you're in full sun vs shade.

[Heel n Toe]

Put a roof on that thing to keep the sun off it. Screen it in to keep the bugs and critters out.

[1990C4S]

I don't know hw you keep the chlorine levels up in that weather. Or are you on salt?

[unclebilly]

Originally Posted by masraum

30,000 gallons 85º to 95º takes 733.6 Kwh (equal to 2640954377J / 628798661cal / 733599Wh / 2503141 btu). IIRC, 10º∆ is the same whether it's + or -.

Except that the efficiency of a heating device is much greater than the efficiency of a cooling device.

Everything being equal, it takes more electricity to cool 10° than it does to heat 10°.

A heater is a heating element which is basically a resister with power applied. Water is circulated past the heated element. Requires a heating element and a water pump.

A cooler involves compressing a refrigerant to pressures above 100psi, running it through a cooler, then expanding it through a nozzle to get evaporation (and hence cooling). The pool water is circulated through a heat exchanger where the cold refrigerant cools the water and the refrigerant is compressed again… lots of moving parts, indirect energy conversion, requires a compressor, a fan, and a water pump.

Agreed that the energy required to heat water 10° is the same as to cool it 10° but practically, the energy inputs needed to cut a cooler to accomplish this are probably 2-3X more than a heater.

[masraum]

Originally Posted by unclebilly

Except that the efficiency of a heating device is much greater than the efficiency of a cooling device.

Everything being equal, it takes more electricity to cool 10° than it does to heat 10°.

A heater is a heating element which is basically a resister with power applied. Water is circulated past the heated element. Requires a heating element and a water pump.

A cooler involves compressing a refrigerant to pressures above 100psi, running it through a cooler, then expanding it through a nozzle to get evaporation (and hence cooling). The pool water is circulated through a heat exchanger where the cold refrigerant cools the water and the refrigerant is compressed again… lots of moving parts, indirect energy conversion, requires a compressor, a fan, and a water pump.

Agreed that the energy required to heat water 10° is the same as to cool it 10° but practically, the energy inputs needed to cut a cooler to accomplish this are probably 2-3X more than a heater.

Right, that was what I was talking about, the energy required (gained to heat or lost to cool). I wasn't getting specific about the method of heating, electricity required, that sort of thing. My thought is that in this area, a solar heater is most common, and I would think that a solar heater could also be a used as a cooler. A quick google search says that a solar heater can be a cooler if it's run at night.
https://floridasolardesigngroup.com/cool-your-pool-with-a-solar-pool-heater/
It works like a radiator.

[red-beard]

Originally Posted by unclebilly

Except that the efficiency of a heating device is much greater than the efficiency of a cooling device.

Everything being equal, it takes more electricity to cool 10° than it does to heat 10°.

Unless you are using an Evaporative cooler. Those use up water in the process, but do not use much electricity (fan).

The best you can do with an evaporative cooler is the "Wet Bulb" temperature. For example, today it is 100F and RH41%, this leads to a dew point of 71, a "Feels Like" of 123 and a wetbulb of 80.61.

So, as my pool water circulates at 25 GPM, it is cooled to 80.61F. Assuming I start at 93F water, I'll cool about halfway to the dewpoint with a full turnover of water, which is about 17 hours. Call it a day. The sun adds about 3 degrees per day, so I will still need to keep running the evap chiller several hours per day to keep the water about 86F.

The GPC 210 uses 528 Watts. 10 hours is about 5kWh, which is about 50 cents per day for me.

[masraum]

Originally Posted by red-beard

Unless you are using an Evaporative cooler. Those use up water in the process, but do not use much electricity (fan).

The best you can do with an evaporative cooler is the "Wet Bulb" temperature. For example, today it is 100F and RH41%, this leads to a dew point of 71, a "Feels Like" of 123 and a wetbulb of 80.61.

So, as my pool water circulates at 25 GPM, it is cooled to 80.61F. Assuming I start at 93F water, I'll cool about halfway to the dewpoint with a full turnover of water, which is about 17 hours. Call it a day. The sun adds about 3 degrees per day, so I will still need to keep running the evap chiller several hours per day to keep the water about 86F.

The GPC 210 uses 528 Watts. 10 hours is about 5kWh, which is about 50 cents per day for me.

All of this guessing, round numbers, and wild approximations. Do you have any real, specific numbers?

sheesh!

[john70t]

There are retractable pool covers which would keep sunlight and some debris off the water.

An air gap would ensure positive upwards flow of any heat differential: ie pool is warmer than the air.

4 feet below the frost line it's probably about 40-60deg constant which would be a heat sink unless it's insulated.

[red-beard]

Originally Posted by john70t

There are retractable pool covers which would keep sunlight and some debris off the water.

An air gap would ensure positive upwards flow of any heat differential: ie pool is warmer than the air.

4 feet below the frost line it's probably about 40-60deg constant which would be a heat sink unless it's insulated.

We don't have a Frost line. The ground temp here is around 70-80F. And while a retractable pool cover would be nice...it would be extremely costly to install. Would love one!

[masraum]

Originally Posted by john70t

There are retractable pool covers which would keep sunlight and some debris off the water.

An air gap would ensure positive upwards flow of any heat differential: ie pool is warmer than the air.

4 feet below the frost line it's probably about 40-60deg constant which would be a heat sink unless it's insulated.

My guess is that there's not a frost line at SM's yard any more than mine has one. It's probably like looking for a frost line in FL. You're going to be looking until the next ice age.

I have a well for water here and my cold water is ~78º. Some of that warmth is probably from the ground that the water has no run through to get from the well to the house, but that's still pretty warm.

[john70t]

You guys got some kind of thermal differential or heat pumps wouldn't work.
(why not for pools?)
https://www.outlookindia.com/international/in-photos-icy-winters-snowfall-in-texas-photos-258659

[gacook]

My pool's only about 80 right now...was thinking I need to get a solar blanket to warm it up some