Would this work to cool a pool?

[zea3]

I've been thinking (always a dangerous thing). I have heard people with solar panels can run them at night to provide some cooling for the pool water. What if you have solar panels set up in a heavily shaded area and run them night or day? Would that create a cooling effect? I have tried the fountain but it doesn't provide much of a drop unless you are standing under it.

Our water gets up to 90 or more in the summer and a chiller is cost prohibitive at this time.

 

[Bama Rambler]

It would have to be a pretty heavily shaded area but it would work at night all the same.

I've been thinking of installing one more for cooling than for heating. During the heat of summer our pool will get like bath water it's so warm.

 

[dmanb2b]

As long as the panels are in the shade and the air temp is lower than the pool water temp, you would be cooling the water (as Bama said, most likely to only occur at night though)...at least that's my thinking and we know that is dangerous

 

[Nightmare]

Could you plumb a swamp cooler into the system? They cost very little to run, but I know at some point the evaporation effect just stops.

I found this :?

http://www.instructables.com/id/DIY-swi ... ol-cooler/

 

[waste]

Nice question, Zea

A few years ago I dreamed up a system that was underground to provide a cooling effect on pools (I never pursued it, probably because I live in the NE and too hot pool water isn't often an issue :lol: )

 

[Just-a-PB]

Have you thought about Geothermal.
Go down 5 to 10' and you have a constant around 55 degrees.
Lay in a bunch of 1.5" PVC, and you can cool in the summer and heat in the winter.

Hey, :idea: the bottom of the pools we build are that deep. What if we put a grid of pipes under the pool for this purpose before we shot it.
By golly I am a genius.
Patent office here I come.

 

[Nightmare]

Until a pipe breaks and the pool falls into the sinkhole.

 

[duraleigh]

I have had such great luck with my home-made pool cooler, it would be hard to suggest anything else. [attachment=0:f0h2ystl]poolcooler.jpg[/attachment:f0h2ystl]

zea3, I suspect your fountain is not effective because the volume of water you are throwing into the air is not large enough. By tapping one of my three returns and closing off one more, this piece of drilled PVC pipe cools my rather large pool about 4 degrees in just a couple of days.

 

[denisbaldwin]

I, for one, love bath water-like pool water.

 

[Just-a-PB]

[Until a pipe breaks and the pool falls into the sinkhole.]

Bet your fun at parties.
Explain to me how those pipes would be any different then the hundreds of feet of pipe we put in with an infloor system?
pipes don't just break. Properly installed they will be there for 50years plus.
If you were really concerned you could run a manifold system each with a separate run.

 

[clyopoolboy]

I have had such great luck with my home-made pool cooler, it would be hard to suggest anything else. [attachment=0:15w7393p]poolcooler.jpg[/attachment:15w7393p]

zea3, I suspect your fountain is not effective because the volume of water you are throwing into the air is not large enough. By tapping one of my three returns and closing off one more, this piece of drilled PVC pipe cools my rather large pool about 4 degrees in just a couple of days.

I will have to second that duraleigh and thanks for the idea. I have to turn mine off sometimes to let the water get warmer. It will cool it by about 4 degrees

 

[zea3]

I have had such great luck with my home-made pool cooler, it would be hard to suggest anything else. [attachment=0:3dsng72q]poolcooler.jpg[/attachment:3dsng72q]

zea3, I suspect your fountain is not effective because the volume of water you are throwing into the air is not large enough. By tapping one of my three returns and closing off one more, this piece of drilled PVC pipe cools my rather large pool about 4 degrees in just a couple of days.

I will have to second that duraleigh and thanks for the idea. I have to turn mine off sometimes to let the water get warmer. It will cool it by about 4 degrees

But my dainty little above ground only has 1 return! The fountain is about 12" long, but it can toss water up pretty high, but I haven't tried it since September when I switched out the 1.5 hp pump for a 1 hp 2 speed.

 

[danb]

I wonder how much ice (wet) it would take to make a significant temp change in say a 15000 gal ag pool.

 

[anonapersona]

I switch my filter run times to primarily after dark when the pool temp gets over 88 degrees. The Polaris runs a few hours during the day and the waterfall comes on for 30 minutes twice a day so there is some circulation while the sun is up. But most of the real circulation occurs after midnight. I will see an effect from this for as long as the evenings are actually somewhat cool. For the month of July it still works. August is a different story. Once we get into predawn temps that are still above 80 degrees, even this has little effect.
I have been in a pool that had a spray bar like Duraleigh's and if the fountain is high enough it does a substantial job of cooling the pool. Filter and pump baskets must be clean and it would be nice to have a fast way to close off one extra return to boost that fountain height to something like seen it that photo. A puny 2 foot spray will not do much.

 

[Lershac]

I wonder how much ice (wet) it would take to make a significant temp change in say a 15000 gal ag pool.

Well you significant heat absorber there would be the transformation energy it takes to actually change the ice from a solid to a liquid.

So, an example...

for a 15000 gal pool, thats 15000gal X 3.7854118 kg/gal = 56781 kg (approx) or 56781000g (approx)

Lets say the starting temperature of the pool is 92deg F
Target temperature is 85 deg f
We will ignore the heat loss/gain through the sides and bottom of the pool for this example, as well as to-from the air.

Change in temperature desired is 7 deg F
Thats 33.33 deg C to 29.44 deg C a change of 3.89 deg C

lets also assume that the ice is at -10 deg C starting.

The target temperature for the ice is also 85 deg F (29.44 deg C)

The specific heat of water is 4.186 joule/gram °C

The heat of transformation for water ice is 333 kJ/kg or 333 J/G

The specific heat of water type ice is 2.1 j/g °C at 1 atmosphere (we are going to assume sea level here as well)

so we are going to wind up with some unknown mass amount at 29.44 °C . that mass will be Z

We need an energy budget, so taking water through a 3.89 °C change will require 56781000g (mass of pool water) X 4.186 J/g deg C X 3.89 = 924595685 joules to be absorbed by the ice on it way to 85 deg F

so we have 3 components to getting the ice to 85 deg F. Heating the ice to 0 deg C, melting the ice, then taking the now cold water to 85 deg F.

heating the ice 2.1 j/g deg C X 10 deg C X Z g = 21Z
melting the ice 333 j/g X Zg = 333Z
heating the cold water 4.186 j/g deg C X 29.44 X Zg = 1232.3584Z

Add all those up =1536.3584Z which has to equal 924595685, so solving for Z is 601810g (rounding)

so thats 601 Kg of ice.

or 1326.7617354 lb of ice.

if you buy it in 20 lb bags, thats 66 bags of ice. :blah:

 

[smccull]

Could you plumb a swamp cooler into the system? They cost very little to run, but I know at some point the evaporation effect just stops.

I found this :?

http://www.instructables.com/id/DIY-swi ... ol-cooler/

I'm pretty sure those glacier brand coolers are nothing more than a swamp cooler. Evaporation is the best solution - water is cheap and carries away a lot of energy when it evaps.

 

[Lershac]

A manitowoc ice maker with that capacity would run you about 4K (plus installation). and then running costs on top of that. Plus a cute guy or girl to constantly shovel the ice into the pool.

It may be cheaper in the long run to install a heat pump and keep the water at your desired temp.

 

[SJSwimmer]

Hey, :idea: What if we put a grid of pipes under the pool for this purpose before we shot it.

Patent office here I come.

I'm not so sure. Say it's summer, water temp is 85. 85 degree water goes through pipes, gets cooled to 60. The ground adjacent to those pipes isn't 55 anymore, and it'll take time for that heat to get dissipated, so more water flows down and is only cooled to 65, ..., something about equilibrium. Gotta look at an old thermo book before you go to those patent lawyers. When you submit, do you mind dropping off my patent for a perpetual motion machine?

It's a neat idea, and I'd do some homework before a new dig.

 

[Lershac]

i am thinking it would take alot more than just the footprint of the pool itself to cool enough water (or heat it) to address the pool temperature. A system I saw installed to cool a 3000 sf house (and heat it) was over an two acres in size. They dug out this field to a depth of about 8 feet, laid in the pipe and then covered it back up. thats ALOT of dirt.

Plus if you do it under the pool, wouldnt the ground already be heated (or cooled) quite a bit by the swimming pool right above it?

 

[jb]

I'm on team duraleigh and the fountain. I suceeded last year in making the pool drop. I got a 4 degree drop also and mine was a grecian style that you anchor out to the middle of the pool and hook up to your pool cleaner line. It has mega flow. Even more than duraleighs (not trying to brag) as it has about 20 holes and it goes nuts thru all of them. Kids love it too. Something else to do. Our pool was 90 and it dropped to 86 which for me is the ideal water temperature. Without the fountain, our pool stays 10 degrees under the average previous 3 days high temperature. So I am good if we stay at or under 100. Here in N Texas we usually get about a dozen 102 days even then we'll still be close.

I\Duraleigh or anyone else, I have a question. Do you run your fountain at night or in the day? Last year I ran mine mostly at night thinking the coller air temperature would cool the water falling back to the pool faster. But now I'm not so sure. DO a google search on effectiveness of swamp or evaporative coolers (which our fountains are a primitive form of, no?) When you find a site that gives calcs. You see the effectiveness of the cooling increases with temperature difference between the dry bulb and wet bulb temperatures. THey depend on humidity too and you have to calculate those numbers, but I am thinking 90 pool water going through 100 air will cool fast than 90 pool water going thru 90 air, same humidity assumed. Or am I crazy. I may have to start a chart and run my pool for a week in the day and a week in the night and see, same hours. I will have to check relative humidity and results will only be valid if humidity is similar thru testing.