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.

Step 1: 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.

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.

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

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).

Step 5: Updates

Ok, I have made some updates to it since I posted this instructible.

1. I cut the kink out, making the flow faster and it cools better.

2. I got another cooler that is bigger, more insulated, and doesn't leak(FINALLY! No more moldy carpets!)

3. I have re-worked the system with a radiator!

4. I also added some safety labels, pic 3.

5. I added an internal coil of copper to the cooler. The returning water runs through the copper, transferring more heat. This method works a lot better than my original method.

6. I insulated the water lines

7. I added more copper on the back of the fan for more heat exchange.

8. I made another version. https://www.instructables.com/id/home-made-air-conditioner-version-two/#



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141 Discussions


8 years ago on Introduction

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!

2 replies

Reply 3 years ago on Introduction

hello danial i am also working on it i need explainantion do we extract water from the tank by copper tubes? or by vinyl tube? why is fish pump used? how do you make it step by step? how and where copper tubes used? one end in water tank? other end? how vinyl tube is used? one end in h2o the other is connected to pump? may i call you? can you talk to me over skype? i need you help please...................................asif 03463233780


Reply 2 years ago

copper is used so it can release coolness better then plastic/rubber. So you want copper strictly in front of the fan and no where else. You can use rubber pipes from and to the tank, with copper in the middle in front of the fan.

Fish tank pump moves water slower. You can experiment with different pumps or try controlling their speed.

Cold water you have to produce. this machine can not make it for you.

Use your imagination :)


9 years ago on Step 3

Hey thanks probably use this in a garage or my shed and put it on a cart but great Instructable!!! :-)


9 years ago on Step 5

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.

3 replies

Reply 9 years ago on Introduction

Attached are the images, I did things a bit differently, but it seems to work just fine.


Reply 9 years ago on Introduction

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?


9 years ago on Introduction

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... :-(


Reply 8 months ago

It would seem the HVAC goons found him? He's now on shows on how much copper you can eat and live.


1 year ago

Tested building two versions of this today since it was freaking NINETY-FIVE today and went thru 40 pounds of ice in only 4 hours. I was using an older foam cooler which leaked thru the pores but my radiator setup did a GREAT job of delivering the cold.


2 years ago

I did it today but the copper sweats profusely.


3 years ago on Introduction

do you dip both ends of the pipe into water? what is that makes the water cool? heat exchanger? pump? does the pump circulate the water from oneside of the box and bring it back?


7 years ago on Introduction

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....

1 reply

Reply 3 years ago

I don't think these are built to cool a full room. I think these are more of a personal or very small space cooler


3 years ago

How well would this cool down a small camper? Talking a 1968 apache eagle. It's about 10 feet but I want to say 30. Big enough for two full beds on either side and. A 5 by 8 floor. I could assume it would get the job done. This is what it would be used for only