Homemade Air Conditioner




Posted in WorkshopEnergy

Introduction: Homemade Air Conditioner

Before I get started, I have to give props to Geoff Milburn, at http://www.gmilburn.ca/ac/ whose plan it was I copied. I'm not smart enough to think up something like this on my own. That being said, one of the places I work has no AC, but I'm allowed to have fans, so this seemed like a good project for me. It's not perfect yet, but it does cool the air better than just a fan.

Step 1: Attach Copper Tubing to the Fan

I took the grate off of my fan, so I could put the heat exchanger on the inside, hopefully making it look better. I'm using copper tubing as the heat exchanger, although you could use something else, as copper is not cheap, and not easy to work with. As you can see in the second photo, it's very easy to kink the tubing, in which case, you stop the flow of water. I grabbed a hole saw to use as a die to wrap the tubing around, and the teeth held nicely against the grate of the fan. As I was going along, I used zip ties to hold the tubing to the grate. Of course, because this will be inside the fan, make sure to clip off the loose ends. Also, make sure that you have both ends of the copper tubing sticking out of the fan, so you can hook up the tubes to the pump.

Step 2: Attaching the Tubing to the Pump

Now, the cheapie pump I bought would only fit 1/2" ID tubing, and they didn't have anything that would downsize it to 1/4" for me, so I just rigged it up. As you can see in the first and second photos, 1/4" tubing fits quite nicely around the copper tubing. In the third photo, you can see how I just inserted the 1/4" into 3/8", into 1/2" tubing, which would then fit onto the pump. This of course leaked, which necessitated the use of hose clamps, photo 4. I feel that this greatly reduces the effeciency of my pump, but now I have a reason to buy a bigger, stronger, more manly pump! Either that, or buy bigger copper tubing, which is not as exciting.

Step 3: Submerging the Pump and Testing It Out

I bought a foam cooler to hold my coolant(ice water), as I have easy (free) access to both water and ice. Once I had it all hooked up, with one tube going from the pump into the heat exchanger, and another from the heat exchanger back to the cooler, I submerged the pump and plugged it in. At this point you'll be able to tell whether or not you have leaks real quick. If you do, just shut it off and tighten things up. If you've got a hole in your copper tubing from over-zealous bending, you might have a tricky problem to solve. I didn't have that problem, so I couldn't begin to tell you how to solve it. (I am partial to JB Weld for all things broken though) I've noticed that towards the end of the copper tubing, I'm not getting any condensation, which means by the end, the water has lost it's cooling effect. When I get a bigger pump, the water will flow much faster, and hopefully won't warm up as much. Well, that's about it, any suggestions would be welcome!

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You can't just throw tubing in there like that and call it a day. It's not efficient, and does about as much cold air as a seltzer bottle. You have to wind it in a coil for the coolant to actually have any effect, whatsoever.

a nifty modification qould be to use 2 coolers one inside the other with water in the smaller one surrounded by dry ice in the larger one it would super cool the water with less waste and if you wanted to get fancy wrap some of the copper tubeing around the smaller cooling to have direct contact with the dry ice causeing a greater surface area for cooling. also add alil salt to lower the waters cooling temp

What a cool article ha get it? Cool! Seriously am gonna make this! Not looking forward the the $$ copper tubing but the rest is great!

Could someone provide any efficiency specs(what temperature can this cooler maintain)?

I have the solution to all of the rust and saltwater problems. Just get a pump that does not need to be submerged. Get one that has an intake and output nipple on it for hooking up to tubing then run from your output to a plastic tube that goes to the coil of copper then from the copper output put a plastic tube that goes in to the cooler and forms another coil. then back in to your pump. Fill the system with antifreeze. Now your copper tubing is isolated from the salt water and you actually get some rust prevention from the anti freeze. Oh and BTW fill the cooler with ice, rock salt, and salt water this will super cool it. It will probably form Ice on the coil rather then condensation.

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Great idea, plus removing the submersible pump will help prevent the water from warming up from the pump running. The pump generates heat too and will cause the water to warm up faster!


Isn't it better to use an old car radiator instead with the in built fan rotating towards you?

For the people wanting to cool their cars.

Make sure you have a white car, they don't get half as hot! A paint job is probably worthwhile if you are a PI and don't want to trade your car. Instead of colling your car, freeze some ice cushions to sit on, A few layers of fleece or a folded towel and it can be adjusted for the cooling you need.

I made a homemade AC using 20 W motor,ice box,copper windings and all other but the effect is not coming as i expected ,i.e,the cooling effect is not MUCH as we expected from so much hard work...

PLEASE help me out of this (to increase the cooling effect) .

I covered the ice box with aluminium foil.

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Your work looks neat man. Here are some points...You should add coils behind the fan as well and increase the flow of water by installing a better pump. Insulating the pipes between the ice box and the fan can prevent the temperature to increase while in transfer. Also, try to shorten the distance as far as possible. Keep the fan speed low, so that the air may have sufficient time to stay in contact with the coil and become cool in the process.


I am a PI and want to make a rig to cool my van(130 F). I need suggestions (& spelling tips).

9 replies

STC here: You want to cool a van, huh... OK, do this -- Get a car or truck heater core from a junk yard, any kind.. Now get a bilge pump (pump for draining water out of a boat). Ice chest & hose to fit. Put the pump in ice chest with hose connected to out put of pump. Run hose to heater core & output of heater core back to ice chest. Now connect a small fan in front of heater core so the fan is pulling air through the heater core, not pushing it. As you know: You can do more work with a vacuum than with pressure. Place crushed ice in chest with one gallon of water. Now as the fan & pump are 12 volt just fix a plug so they can be plugged into the lighter socket. WALA COLD AIR................ If you put the heater core & the fan in a small box it will work much better. I used this setup some time back in my little motorhome when we were camping in the boonies. Had us looking for the covers... Nother though, If you had a solar panel that put out enough current, you could run this thing all day from it and keep that van cool all day, just add some ice as required. will work to keep a tent cool too.. many uses. STC we gone

hey hae u done this project ????
and if yes then does it cools as ac or not

yes it cools the as a ac i have tried it......it atleast makes 5-10 degree difference

hey can u plz tel me exctly how u made it...because i made and it is not giving much temperature difference from the fan

I am living in India and here there is so much hot climate, i have made so much thing from instructables Please tell me what, if i use a radiator of car and fan and make the same as above shown, so it will work or not?? your reply is important for me.

If you can supply enough cold water, why not.....

I just said I did it in a motor home. And yep it cooled like a a/c unit. Had us looking for covers before morning...

I'm interested in cooling down my car too for Private Investigating. I'll just perhaps get a portable a/c unit and small gas powered generator. (silent generator).

How would you not die from the fumes? My small fan makes a loud noise. I have rigged s cooler with a fan that blows in?downward from the top an fore air over ice blocks and then out vent. Melts in the hot van, but i works for a short time. Any info on ac units would be great.