Pool Cooler

[Rumbleehockey03]

Anyone ever plumbed in an automotive style radiator with some electric fans to cool off their pool? I'm thinking of a parallel path on the clean side of the filter that could be used as needed to run the water through the radiator core to pull out excess heat when needed.

Thoughts?

 

[Donldson]

Automotive radiators work so well because the fluid moving through them is several times the temperature of the air going across it, so the heat is easily transferred from the radiator to the air. If 95 degree pool water were moved through it and the air going across it were 80 degrees it will give you much less striking results. Also antifreeze has a lot of anti-corrosive additives to protect the radiator, pool water does not. This won't bode well for the long-term life of the unit.

Really a small fountain will likely give you better results at a fraction of the effort. Or if you really want something to be plumbed in consider a heat pump that can be run in reverse to also chill the water. That way you have something that can extend your swim season and also keep the water comfortable in the worst heat of the summer.

 

[Rumbleehockey03]

Automotive radiators work so well because the fluid moving through them is several times the temperature of the air going across it, so the heat is easily transferred from the radiator to the air. If 95 degree pool water were moved through it and the air going across it were 80 degrees it will give you much less striking results. Also antifreeze has a lot of anti-corrosive additives to protect the radiator, pool water does not. This won't bode well for the long-term life of the unit.

Really a small fountain will likely give you better results at a fraction of the effort. Or if you really want something to be plumbed in consider a heat pump that can be run in reverse to also chill the water. That way you have something that can extend your swim season and also keep the water comfortable in the worst heat of the summer.

Thanks for that...didn't really think about the delta-T when that thought crossed my mind. I'm actually expecting a small fountain from amazon today and hope to see it work well tonight because the pool water is already 92° after being filled only 1 week ago (YIKES). Hopefully that'll do the trick and I can stop wasting time at work thinking about ways to rig up a cooler without actaully buying a cooler. haha

 

[duraleigh]

A "small" fountain will have little effect. You will need a large fountain to throw a fine spray high into the air to get evaporative cooling working for you.

I am not sure what you mean by small but don't dabble. You are asking for a significant energy exchange and that will take a significant vehicle to make it work.

You can search "pool cooler" on this forum for several examples

 

[Rumbleehockey03]

I wanted to follow-up here in case anyone is searching for a way to cool their pool water. I purchased a simple fountain from amazon (This Fountain) and have been running it 24/7 with my pump on low , which is my normal pump run schedule for now until I see what that power bill looks like. Max pool temp before the fountain hit 93 in the afternoon with air temps all week approaching 100 in the daytime and mid 70s at night. Before the fountain, the pool was increasing max temp a couple degrees per day. Yesterday my max temp leveled off at a touch under 90 degrees after 3 full days of running the fountain and morning temps are around 85...nice and comfy. My pH has also come up from ~7.2 to about 7.6 over that time span so I'll probably grab some acid to have on hand assuming that pH will continue that slow rise from aeration.

Oh, I also fixed an umbrella to my deck that provides at least a little bit of shade in the afternoon hours. It's only an 8' umbrella for a 24' pool, but it's better than nothing I guess...can't hurt anyway.

 

[woodyp]

radiator = copper tubing = no thank you! (at least I think they're copper)

 

[smracing]

radiator = copper tubing = no thank you! (at least I think they're copper)

All new radiators are aluminum., well except for cheap aftermarket replacements.

 

[Rumbleehockey03]

Another note, I work in engineering for diesel engine systems and have a cooling expert in my work group. He's going to run some numbers for me using a standard cooler size that we use at work along with airflow from a standard electric fan that we'll select and see what kind of heat rejection I would get overnight from a system like that. It'll take plenty of math but we should be able to take the kW of heat rejection and use that to calculate expected temperature drop in the pool given a certain air/water temperature delta....this should be fun

 

[duraleigh]

..this should be fun

I agree. It may be noticeably helpful in small to mid-size pool. Interested to see the numbers.

 

[woodyp]

"All new radiators are aluminum., well except for cheap aftermarket replacements. "

Thanks....God I'm Old School!

 

[duraleigh]

Just a side note......copper pipes alone are just fine. It's when you let your pH go South for prolonged periods that copper gets into your pool in soluble form.

 

[orbitup]

That reminded me of a picture I saw of someone using a radiator as a heater.

 

[chayne]

here is how i try to keep my pool water cooler

 

[duraleigh]

chane,

If you would modify that and make your water into tinier droplets (like a spray, almost a mist) you would get much, much more cooling.

 

[chayne]

tinier droplets huh? any ideas?

 

[AimeeH]

This does a decent job for me...especially if run overnight. It sprays further than it looks in this picture.

 

[tstex]

The simple facts are that w the summer heat of the South and evening/nighttime sustained ambient air temps, this is a losing battle on cost-effectiveness and effort per decent temp reduction. The only way you will achieve any real decline in temp is to engage a true chiller from the time the sun goes down until the next morning. The specific heat of water takes a lot of energy to convert hot water to cool water, especially when the sun is out and the ambient temps are rising.

Unless you employ a true chiller type system, the only way to drop the pool water temp of any significance, is to drain your water by 2+ ft when the sun goes down, then add water in the 70-75 degree range from pipes that are 5-6ft below the ground. However, the next day all that water will be heated up again if the sun is out all day. It's a costly fix for a short term gain. The same in the winter when you heat a pool...it cools down quickly w cold outside temps.

 

[duraleigh]

tstx,

When you spray fine water droplets into the air, some of that water evaporates. The evaporative process releases heat and you can actually FEEL the colder water falling back into the pool.

We could drop our (BIG pool) water temp until it was too cold to swim (from 88 down to about 82) and we had to shut the aerator down so we didn't lose any more heat. We did this season after season and it was never a losing battle. It works.

The energy used is virtually nil since the already operating pool pump provides the power.

 

[duraleigh]

tinier droplets huh? any ideas?

Yes. aimeeH's pic right below your post is an example.

 

[tstex]

Thanks Dave...My reference to energy costs were if you had to use a chiller, then the next day it would be reheated via sun and ambient air. If you can take a 42,000 gal pool and cool it from 93-95 degrees to 80-82 a thermal transfer via evaporation on, you surely have me beat. Many times in Houston w night ambient air of 85 degrees and 95% humidity, the heat transfer is very minimal w high RH and high ambient air....I'd love to be able to feel the water was too cold to swim in during anytime of the summer.

thanks for your posts - tstex