Introduction: DIY Swimming Pool Cooler.

Picture of DIY Swimming Pool Cooler.

Build a mechanically drafted, counter-flow cooling tower for your swimming pool. These would be especially useful to people living in gulf coast states and the SW deserts.

For more detailed instructions: DIY Pool Cooler

Step 1: Obtain or Build Some Kind of "tower".

Picture of Obtain or Build Some Kind of "tower".

First you will need a "tower". Pictured are a couple of options we have used. The first was made from a couple of HDPE barrels. The second is made from PVC pipe, fittings, and corrugated roofing material. Your tower will need to have some sort of catch basin at the bottom, and area for fill material in the center, an area for a water sprayer systems, and finally you'll need a fan that fits the top.

Learn more at:

Step 2: Cut Up the Fill Material.

Picture of Cut Up the Fill Material.

The fill material is the most critical part of getting this to work right. We used 26" by 96" sheets and cut them down to five smaller sheets of 21" by 16.25". These smaller sheets are cut on the bias of the corrugations (see photo). The sheets are stacked with sheets alternating their corrugations.

For more details: DIY Pool Cooler

Step 3: Next Install the Water Sprayer System.

Picture of Next Install the Water Sprayer System.

Construct either a fixed manifold of pipes with holes to spray water or a rotating spray arm. The picture should give you the method for building the rotating arm.

Additional info can be found here.

Step 4: Top It Off and Try It Out.

Picture of Top It Off and Try It Out.

Finally, top off your creation with a cheap box fan (I prefer the "weather resistant" variety that comes with a GFCI on the cord). Our versions return the water to the pool using gravity, so you have to set it up next to the pool. Good luck and enjoy a pool that doesn't feel like bath water.

Complete details:


AARPBoy (author)2015-08-11

You know, there's nothing quite like talking to someone who's already been there and done that. I hadn't really thought through the slope of the trash can sides, therefore, I was headed for a trainwreck. Thanks for the valuable tip.

I'm living "down south" and it was 106 here yesterday afternoon. Good news is, it was only 102 in the shade. My spa has a spillover into my pool. The spillover runs with a very low water volume. After the water sits in the spa and marinates in the wicked hot afternoon heat, it's easily 5 degrees+ warmer than the pool itself as it runs over and back into the pool. I'm using a couple of evaporative fountains on the pump return in the pool proper, and they do a pretty good job. I see approximately a 5-6 degree drop in pool temp during the day after the humidity drops mid-morning. Problem is, I'm solar-reheating my water as it circulates back through the spa. They don't call it a hot-tub for nothing!

Your rolling solution to the cooling tower is perfect for "as needed" cooling of the spa before expected kids or guests arrive.

I look forward to your further posts to this thread.

Thanks again.

okimprollydrunk made it! (author)2015-08-03

Ok, so I built a version of this over the weekend. I haven't tested out the actual temp drop, but the water that flows down is noticeably cooler. It feels like ~15 degrees cooler than it goes in.

I opted for two rolling 45 gallon Otto trash cans from Home Depot. They stack nicely, have a locking lid to keep crap out of the system, have wheels to improve the mobility, and are the perfect size for a cheap $16 box fan to sit on top without any rigging.

For these, I needed 6 - 8' panels of plastic corrugated roofing, a few 2' pieces of 1/2" PVC, some 1/2" and 3/4" hose, soaker hose sprayer tips, and quite a few fittings. Here are some pics to show the results.

Since the original author's description is lacking details and the site he references seems to be down, I had to figure out most of this on my own. If it's of interest to people, I could create a more detailed Instructible.

AARPBoy (author)okimprollydrunk2015-08-07

hey okimprollydrunk, ok i've been watching this thread for a while and had been thinking that a trash can might make a good tower. I'm real glad to see you took that course on your build.

am very interested in your project and, since you mentioned it, I for one would like to encourage you to do a more detailed Instructible on this. It looks exactly like what I want to try.

thanks to you and all for sharing your work and comments.

- aarpboy

okimprollydrunk (author)AARPBoy2015-08-10

I will start working up what the shopping list is. I will say that the trash cans add a lot of convenience to this project. The one issue is that they are tapered smaller at the bottom. This makes the water try to drip out of the cut-outs in the can onto the pool deck. I have remedied this by adhering weather stripping above the cut-outs to have the water drip from a more inward point. This works effectively enough. If I were doing it over, I might cut and score a section of the can plastic above the holes and fold it in so that the can's plastic created a drip shelf.

Awesome design! Do you have any measurements of the temperature drop as of yet?

Justin, I used it this past weekend prior to a party we had. I ran it from Thursday night until mid-day on Saturday. I have 2 revelations:

1. This design doesn't move a substantial amount of water, so it probably isn't large enough to be as effective as I want it to be on my 12,000 gallon pool.

2. The "wet bulb" temperature is a major influencing factor. Our humidity was in the 90% range this weekend. That made it miserable and made the cooler ineffective. Because of the high humidity, the water couldn't evaporate effectively, thus it did not cool the temp much.

From my temperature tracking, the temperature actually increased across my measurements. Tehrefore, it was inconclusive. These were the hottest and most humid days of the summer so far. I'll definitely need to do more testing.

By the way, I'm in NW Arkansas, for reference.

johnrm321 (author)2015-08-03

This is literally ingenious. My family has been pool builders in san antonio for over 24 years, and we have never seen anything like this. If you've ever been to Texas you know how hot it gets in the summers too. Wow, just goes to show what a little creativity can bring.

sshekhar12 (author)2014-02-08

hey dave, please let me know what is the temperature drop u get with this device. as well as, if we use various cooling pads will there be any variation in the temperature drop? its imp as i am working on a project based on evaporative cooler

kstanley4 (author)2011-07-27

I also live in Dallas my pool temp 93 it feels like bathwater.Great ideal !!! I was thinking of a tower letting the water run down pine slats with the tower open allowing the wind to be your evaporating fan..??do you think that would work??

cmorris12 (author)2011-07-20

looks like you turn the fan down ..... blowing over the water tricling across the fillers(coils)... in that your making a radiator ( some what ) right.

Bartboy (author)2009-07-04

So it cools the pool? lol

Dave7F (author)Bartboy2009-07-06

It cools the pool and in turn, cools me! I am just about to hook it up and run it for the a third season, with some minor modifications to improve efficiency (fan is now integrated into the barrel to remove nearly all parts that could rust, larger pipes for better water flow, etc.),. If I get around to it, I will post some pictures of the current version.

Bartboy (author)Dave7F2009-07-07

I've never been somewhere where the pool was too warm...

james1913 (author)Bartboy2010-08-18

Guess you haven't been to Dallas after months of 90 degrees.

Bartboy (author)james19132010-08-19

Nope. Although, it was 110 in alberta where I'm visiting currently.

enomis1971 (author)Bartboy2009-07-09

You should live in South Louisiana.....

Bartboy (author)enomis19712009-07-09

Mmmmmm...... hot sauce Canada is nice...:P

Redgerr (author)Bartboy2010-06-23

im with Bartboy, i have never heard of one of these however it seems like it would work, very cool

Bartboy (author)Redgerr2010-06-23

Well, I might use it in my house in Ontario, but I don't have a pool there. In Canada, we pay a fortune for pool heaters...

Redgerr (author)Bartboy2010-06-28

pool heaters is where its at, expencive.. but warm none the less

Kaiven (author)Bartboy2010-06-22

LOL. When I walk into my pool, my body temperature goes up.

mikewrobel (author)2010-07-05

I assume the fan blows up (based on some other internet research)?

harry88 (author)2010-07-02

you could do the reverse with a metal jug and your old baseboard heaters

miiwii3 (author)2010-06-26

if only this worked in reverse...

Tray (author)2010-05-14

Im going to give this a shot, in a smaller size for my worm hotel.   Composting worms slow down when they get too warm.  There is another Ible that details building an ice chest based worm hotel that is plumbed with cooling tubes fed from an iced water bucket.  This system would eliminate the need to periodically fill a feed bucket with ice.  Run all the pumps off of a battery that is solar charged, and viola.  COOL IBLE!!

TrPPnN (author)2010-04-14

Hahaha... heater?  daniel... here in the desert, we can't turn off the sun when we want... can you? if you can... you've got to show me how... perhaps write an instructable!

teslafan100 (author)2010-03-10


Danny_Payne (author)2010-01-24

 cant you just turn the heater down? that way, you will save energy!

Dave7F (author)2008-06-23

It occurred to me that this, or a smaller version, might be useful to the water cooled CPU crowd. If you live in a dry climate, it would act as a humidifier for your computer room/office keeping static electricity down at the same time....naah, nobody out there is crazy enough to build that.

kill-a-watt (author)Dave7F2009-12-26
thermoelectric (author)Dave7F2009-03-04

You would be suprised, Many people would be interested in that but the CPU wiuld most likely make too much heat for the cooler to disperse.

beehard44 (author)2009-09-26

PLAN B: Grab an ice maker and plug in the inlet to ur pool and put the ice outlet to your pool. Added feature: Millions of floating toys in your pool!!!!!!! PLAN C: Pour liquid Nitrogen to the water!!!

mr.incredible (author)2009-09-02

This is the same way commercial air conditioning works. Large buildings use cooling towers which is the same thing you have here. The water temp from the evaporation process gets down to 60 deg even in the hottest Florida heat.

Sandisk1duo (author)2009-07-08

well if it's 110 outside, and your pool temperature is 90, using your device would be warming the water

Dave7F (author)Sandisk1duo2009-07-28

Actually, no. Please see my comment to crazyrog17.

crazyrog17 (author)2009-07-14

Could you clarify this a little bit? In the first few steps, explain the ambient wet bulb temperature for everyone and how it works to cool your pool. Did you pump the water into the barrel/sprayers? How? Is the fan blowing down into the barrel and being exhausted at the bottom or pulling up out of the barrel blowing out the top?

Dave7F (author)crazyrog172009-07-28

The easiest way to explain how it cools the pool (even if the water is 90 and the air is 110), is with an phenomenon many of us have probably experienced. If you are wet (even with 90 degree water), and you stand in the wind (even 110 degree wind), you will feel cold. This is because of the heat that is removed by the phase change as the water turns from liquid to vapor. In the case of the pool cooler, the wind is produced by the fan and the cooled water is returned to the pool. The water is pumped by the pool's normal pump. On many pools there is an aerator device (a simple sprayer nozzle). I removed this and installed a threaded reducer to allow attaching a short garden hose that feeds the sprayer assembly. The fan is blowing up and pulling air in at the bottom. The water is flowing down. The design is based on industrial "counter-flow" cooling towers.

hleon (author)2009-06-06

since it is evaporative, wouldn't the pool LOSE water, since it is being transferred to the air?

Dave7F (author)hleon2009-07-06

Yes it does, but only just enough to cool the water to the ambient wet bulb temperature. It is a small price to pay compared to not being able to cool myself in the pool.

altgrave (author)2009-05-29

i've never seen this idea, either, but i do recall lukewarm pools in new jersey. ugh! nicely done!

Patented (author)2008-06-25

Lol! In Canada we try to make our pool warmer!

bmlbytes (author)Patented2008-09-04

I was thinking the same thing. Here in Minnesota, we make our pools warmer. Some people put hot tubs outside, so you can swim with the snow all around.

Dave7F (author)Patented2008-06-25

Living in a desert, I envy that!

T3hpw9ag3 (author)Dave7F2008-06-27

You live in a desert? you must take great care of your lawn, it looks more green than my lawn in Illinois! anyway, nice instructable

Dave7F (author)T3hpw9ag3 2008-06-28

That nice lawn is actually my brothers -- he lives in area that has flood irrigation. MY lawn is much smaller and only looks that nice after a couple of monsoon storms.... Anyway, Thanks!

jojo200517 (author)2008-07-04

That is pretty nice, I hope you washed the barrel out damn good, since I spy a corrosive placard. The pool place tossed in a cheapo fountain when we got ours, and occasionally I put it in when its horribly hot in the summer. It does seem to drop the temperature a few degrees.

looking4ideas (author)2008-07-04

My mom lives in Doha they have cooling and heating lol

curecreator (author)2008-07-02

Nice job with the pool cooler i live in a hot area but my pool is surrounded by evergreens

LinuxH4x0r (author)2008-06-28


Chefboy6382 (author)2008-06-22

very ingenious idea! I assume you are using a pool "jet" to carry the water into the sprayer to cool?

About This Instructable




More by Dave7F:DIY swimming pool cooler.
Add instructable to: