Picture of Home Made Air Conditioner I
I was wanting an air conditioning unit for my tree house. So I thought, why buy a $250 A/C unit, when I could build my own?
It is very low cost to operate, compared to a central a/c, and provides spot cooling/heating, only cooling/heating the areas you want to cool/heat, heatly.

It is also eco friendly, because it uses water as refrigerant, and it can multi-task, cooling/heating the room, while cooling/heating your beverages (or whatever) in the cooler.

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Step 1: Step One: Supplys

Picture of Step One: Supplys
Supplys needed:

Salvage from the house(or Walmart):

1 Box Fan
Screw Driver
Utility Knife
Est. cost $0-$25

Buy at Lowes:

1 Smartpond 155 gal/hr fountain pump
1 20' box of 1/4"(ID) copper tubing
1 20' coil of 3/8"(ID) vinyl tubing
2 hose clamps
1 pack of zip ties
1 Cooler-32qt(8 gallons)
Est. Cost $50.00
Congrats. You just got through step one.

Step 2: Step Two: Build It.

Picture of Step Two: Build It.
take the fan. turn it to where it sits front-up. Start coiling the copper around the fan.
place a zip tie every 6" of copper. Once finished coiling, attach vinyl tube to feed end of copper.
Then, lead the tube to the pump. Connect it. then, cut the tube in half. Clamp the remaining half of tube to the return line, and lead it back into the cooler. Use the hose clamps to clamp down the connection between the copper and the vinyl tubing.

Step 3: Step Three: Enjoy It.

Picture of Step Three: Enjoy It.
Fill the cooler up with water, and plug in the pump. Let it run for 3 minutes, to get the coil cold, and then turn on the fan. Enjoy your new cold stream of air! I have made mods in the updates step.

Step 4: Specs

Picture of Specs
Ok, this unit puts out aprox. 3200 BTU/hr on high.. It uses aprox. 200 surge/120 running watts(if not higher-these are only estimates), and it is better if you use it for spot cooling(ex. blowing on you at night, chilling an area, etc.). See Updates (next step) for my idea for a possible modifacation(3).
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twdaniel4 years ago
This works great! I used a 175GPMH fountain pump and a narrow 48qt cooler with 3 gallons of water. 6 brick sized reusable ice packs last around 4 hours. I used a dremel tool to cut a small portion out of the top of the lid so it would close properly with the pump power cord and tubing, and used spray foam to provide more insulation.

The materials were a little more than the article stated because I purchased them from a local hardware store instead of a big box store.

Cool project!

asanaya5 years ago
Hey thanks probably use this in a garage or my shed and put it on a cart but great Instructable!!! :-)
hooty1025 years ago
Hey, just to let you know, I threw this together in a couple hours yesterday afternoon during the heat and oh man! It RULES for being a quick and cheap alternative to buying a portable AC unit for my apartment. I've got pictures if you ever want to see how I did it.
hleon (author)  hooty1025 years ago
thanks. I would like to see the pics. please post them ASAP
hooty102 hleon5 years ago
Attached are the images, I did things a bit differently, but it seems to work just fine.
hleon (author)  hooty1025 years ago
what size is your copper tubing, and how much did u use? Did you test it with another a/c on, or by itself in a hot room?
yourcat5 years ago
Great project! I'd like to see a peltier device (dunno if I spelled that right) cooling the water, but that would get expensive really quick... :-(
hleon (author)  yourcat5 years ago
(removed by author or community request)
yourcat hleon5 years ago
Not if you did it like in the thing you posted in answers.

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Hey! what name would you give to this project?Please tell it dry air conditioning system?

malcom20147 months ago

Stupid, the copper alone is not worth the price. You might as well buy one.

ifti.quraeshi7 months ago

I was inspired by the short video post on FB about a month ago - I an trying to figure out how to keep the water chilled continuously so that it can be made into a commercially viable product. I tried using a Vortex Tube to chill the water but the air compressor was too expensive, now I plan to put Peltier Modules (Thermolelectric Coolers) in a steel container with 4 gallons of water inside the ice box and see how that works - Have ordered 10 Peltier units at 4 dollars a piece from China. If anyone has any ideas on how to make this system work better and above all with less power consumption, it would be a gold mine. Count me in, I am a 70 year old miner from Pakistan.

jfletcher81 year ago
I just built this system, with a few modifications.

My copper piping (in front of and behind the fan) is in U shapes, similar to the coils on a refrigerator. The entire piping system is closed; the two sets of "coils" pass into and out of the cooler entirely enclosed in copper (similar to a closed-water nuclear reactor). They are filled with 50/50 coolant/water and sealed.

Inside the cooler I have a secondary cooler based on a modified fractional ice distillation system. Their is a tight spiral column suspended away from the sides of the cooler, pumping water (which is chilled at the bottom of the column via dry ice) from bottom to top. The coils returning from the fan flow downwards through the column, giving off heat. Average temp on the surface of the copper coils as they exit the cooler is 64F; average temp after they exit the fan is 81F. I haven't calculated my efficiency in terms of coolant use but it's gotta be pretty good. The pumps use very little power.

The system is further controlled by several simple mercury switch thermostats wired to a Raspberry Pi computer. If the temperature inside the cooler exceeds limits (I forget to replenish the coolant) it shuts the system off. If the ambient temp in the room drops below tolerance the system shuts off (and back on when the temp reaches the upper threshold). Finally, if there is a loss of pressure in any of the tubing (from several one-way valves with pressure sensors mounted thereon) the system shuts down. The system is also fully controllable via cell and Wi-Fi, and will notify me if it shuts down for any reason.

Why do all this extra and go to all the extra expense? Well, because I can. And it was fun. And I had the components lying around anyway. And, well, inside this tough paramedic exterior there's an engineer begging to be set free.

Unfortunately I had a grounding problem that I didn't plan for and the whole system fried itself this summer when I tried to fire it up. I have since fixed the whole-house system and didn't bother rebuilding this.

To the other question, I've been a medic 6 years. Just finished my CCEMT-P, CCP-C, and TP-C.

did the coolant make any difference?

Water with coolant is actually WORSE at cooling than plain water (plain water absorbs more energy per degree change). However, it also lowers the freezing point of the liquid. Since he uses dry ice to cool off the tubing (-121F), the coolant is probably to ensure that the water inside the system doesn't freeze. As a bonus it also provides corrosion resistance :)

Correct, the coolant was not to improve the cooling capacity but to keep things from freezing up completely, and to prevent corrosion (instead of salt, which I also considered, which would have caused problems).

wow! that is nothing short of genius..I love it! do you have any pictures youd be willing to post or send?
and out of long have you been a paramedic?

= )
sohaib889 months ago

I made it but am concerned about the heating that is generated from the pump. I am using:

20ft copper in front of fan (its thinner then in pictures as I dont remember exact size)

5ft copper in cooler (its 1/4)

2000 ltr/hr pump (as pipe is much longer)

When I put pump in cooler, it raised the the water temperature and in place of cool air, fan started to blow hot air!

Now I am thinking of moving pump to a separate box to avoid temperature rise in cooler

Cycleride9 months ago
I just made one with a oscillating fan. the added weight of the water will cancel the oscillation but it works well.
thedorment9 months ago

did you ever think to line the styrofoam cooler with a trash bag? sorry if it was already suggested i didnt read all the comments

Alamarus9 months ago

Hey I am trying the same thing you have but I am not getting very positive results:

130 GPH Fountain Pump

22Qt. Styrofoam Cool from Wal-mart

12" Honeywell Fan

1/4" OD copper pipe (10 ft.) I plan to get more tomorrow (details why below)

1/4" ID Plastic tubing.

I have put everything from Ice to frozen water bottles to frozen cooler packs and only once have I seen condensation on the copper tubbing. It was originally in a 5 gallon Homedepot bucket but the ice seem to melt and the temperature rose very fast so I switched it to the Styrofoam cooler.

I am thinking of adding more copper tubing to the back as some people on here have done so it will allow the air to suck in cold but I am not sure if this will help. Any advise is appreciated. I live in Colorado and live right next to the furnace with alot of electronics in my room. It gets very warm in here.

Any advise is appreciated.

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plucky111 months ago
Plz add the mimium temperature..
Mahitchima2 years ago
hm, it seems like you are using a bit more energy than needed to make this work ?

cut 2 medium big holes in the box, put a big copper pipe through, seal it, make it fit the fan on one end.

then you got the fan dragging air through the box (air gets cooled)

you could use the water pump for something else?

Maybe solder the small copper tubing inside of the other copper pipe in a coil of some sort.
Just a suggestion =)

Great project by the way :)
_Aias2 years ago
That doesnt look like 1/4" copper pipe to me, looks like 3/8 and 1/2 vinyl. ???
jordan69s2 years ago
"Also, where do I find the pump to build my own?" You guys can find that pump at the pet store for a fish tank pump, or find a water fountain on a garage sale and use the water pump! Also, if you could manage more tightly turns on the cooper pipe on the fan, the more cooling the fan will be able to push... Great idea and congrats in putting it all together!
Hairman2 years ago
I do love this idea, however I wanted to ask you what the electricity use is on the fan and the pump, and also the creating of the ice? This you say cost about $80, and I was able to purchase a small, 5,000 btu air con unit for just under $100 bucks Canadian, and it is high efficiency. I was wondering if there is a point where the payout is not there. I know first hand that having fans on in the summer sometimes for hours, equals the use of the air conditioner since the air con need not run in continuous. Again, I applaud your work. I was just considering what I have already considered every summer, as obviously you have too.
Redstormx13 years ago

Here is a more advanced system i have made :P . I didnt want to use a water pump due to more energy been used. but could put these two systems together nicely .
Takelababy3 years ago
I'd tho't about doing something similar by going down thro the floor and laying pipe on the ground in the crawl space and back up to a fan or auto radiator.
billd63 years ago
I made one of these several years ago and was disappointed.

1. The air is really not that cold.

2. The copper tubbing sweats profusely.

3. The fan sprays the condensate everywhere
I have to agree with number one big time. I'm not worried about the condensation as my fan is on top of my reservoir but the unit really just doesn't work. It actually makes the broken central a/c unit of mine look top of the line.
MyEyezHurt3 years ago
I built two of these and neither of them were able to cool down a bedroom by a single degree. I would probably have to buy $5+ of ice to make it do even that much. I live in Florida where the humidity is 60%-70% so maybe that is a variable to consider. It was a fun project but financially it was not a good investment whatsoever. I could have bought a lot of fans for the money I paid to build these....
mhollands3 years ago
I have a question that hopefully someone will be able to answer for me. I know that the high the humidity the most likely chance that condensation will occur. I live around Orange-Fullerton,CA area and it does get up to the 100's with around 50-70% humidity in the summer time. So I was wondering how was the condensation on this setup for those who are in much warm climates with high humidity, so that I be prepared to ensure that it does not drip every where on top of monitoring water flow and temperature and possibility of the need to improve the homemade radiator (copper). Thank you for your time!
I live in Florida and inside my apartment the humidity ranges from 60%-70%. I built two of these and they sweat profusely (as they should). If your unit is not sweating it is not working. The more condensation the better. I put my fan on top of a 20 gallon tub and drilled holes on the lid for the condensation to fall through. I also laid down screen so that nothing got in the tub other than water.
MyEyezHurt3 years ago
I built my own yesterday with 40 foot of 1/4" OD copper tubing winded about 11 times front and back on about the same size fan. My pump is about 130-170Gph and the lift is probably 2 - 2.5ft. The problem I am having is the coils are not sweating. My reservoir is 20 gallons and the water is ice cold. The output flow is a little slow I haven't measured it but do you think that could be the issue? It's not cooling much more than without the coils....
I'd like to add I live in florida where the humidity is at least at 80%. I think this is the main problem, I am going to build another one with larger tubing and with a much faster rate of flow and see what happens...
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