How To Make your Own Homemade Air Conditioner


in Frugality,How To...

Okay technically it’s not an air conditioner it’s an evaporative cooler aka a swamp cooler but definitely provides a level of cooling to your room. I’m not going to lie to you. This is not a 2 minute fix, nor is it for the faint of heart, and finally it’s not the most attractive of contraptions (as was evident from the laughter from my wife and her girlfriend) but it does work.

Quite the sales job Paul so why did you build it? As they say necessity is the mother of invention and we are currently experiencing a heat wave in Seattle where it’s expected that we will break the record for hottest day in our history at 101 degrees. If you know Western Washington State you know that we can take the rain for a year straight no problem but when the mercury heads past 80 degrees the apocalypse is soon to follow. I thought I might take a casual stroll this morning to our local Home Depot to see what kind of cooling options were available. I’m not kidding when I tell you it looked like Whoville on Christmas Day after the Grinch had come. There was a bare area of concrete with a tiny piece of ripped cardboard the only evidence that they carried any form of AC unit or fan. So after a few unsuccessful calls on Craigslist I started scheming to build my own cooling unit.

As you may or may not know evaporative coolers can raise the humidity level in your room hence the name swamp cooler. They are more applicable to less humid areas like my home state of Washington. Odds are if you live in one of the more humid areas you’ve already got an air conditioner that will also act as a dehumidifier.

Components of a Homemade Air Conditioner

Air Conditioner Components

Essentially what we’ll be doing is using the power of evaporative cooling and a fan to bring down the temperature in your room. In this case we’ll be using ice water stored in a cooler that will then cycle through a copper loop in front of a box fan. I’ll leave it to you to head to wikipedia to read up on how the process works, it’s not unlike you sweating to cool down. Myself I’ve done enough sweating so I’ll let the air conditioner do it for me. (Note: this is the perfect project to do some scrounging and modify your design and tailor to whatever you may have on hand that would fulfill the same function). Okay for this project you’ll need to assemble the following components:

  • A Fan (box fan is ideal)
  • A cooler (you could use a Styrofoam cooler or whatever cooler you may have on hand)
  • An aquarium pump (or a pond pump, the higher the Gallons Per Hour the more cooling you’ll get mine is a 132 GPH, also be sure your pump has enough power to push the water to the height required to reach the top of your coil)
  • Copper coil tubing (the particular type of tubing I used was 3/8″ outer diameter copper coil – 20 feet)
  • Vinyl tubing (my pump called for 1/2″ Inner Diameter tubing about 10 feet worth. Hopefully you get better tubing then I did I believe mine is the autokink brand)
  • Reducers and fittings to connect your copper coil to your vinyl tubing and ultimately to your pump. If you are unsure a conversation with a hardware store plumbing expert should get you going in the right direction. They were terribly excited about my project so they were glad to help. (I used 2 1/2″ to 3/8″ couplers that were then fitted with 5/8″ threaded couplers and then screwed in two 1/2″ barbed brass adapters to connect the tubing, finally I used 3 1″ hose clamps to firm it all up)
  • Wood for making box fan outriggers
  • Zip ties for attaching the tubing to your fan


Apply Flux

Assemble the Air Conditioner

  1. First you need to get the copper tubing laid out and get your fittings in place. It was a simple matter of 6 screws holding the protective screen on my box fan so I was able to easily remove it and use it for laying out the copper tubing. Since the copper tubing was already coiled it was a simple matter to gradually and carefully bend it into  a spiral. Give yourself some room between each circle for more surface area.
  2. Attach the fittings to the copper tubing. In my case I needed to solder the joints between the copper tubing and the fittings. You might be able to find some solderless compression type fittings depending on your materials and hardware store availability. That would certainly speed things along and would allow you to avoid having to sweat the fittings together with some form of torch. I prepared all the fittings by sanding the copper tubing and reaming the fittings. I then applied some solder flux to the inside of the fitting and the outside of the tubing. I then proceeded to heat the fitting with my torch until it was hot enough to melt the solder, then I applied the solder. Repeat this for the the other end of the tubing.
  3. Solder the CouplersNow that the fittings were in place I screwed in the barbed adapters for my vinyl hose after applying some Teflon tape to the threads.
  4. The vinyl tubing slipped over the barbs and then I added two screw-type clamps to the barbs.
  5. The pump had a special adapter that I inserted into the vinyl tubing and then again used a screw clamp to secure the tubing.
  6. Now is a good time to test your setup for leaks. Fill your cooler with some water, submerge the pump and connect the tubing to your pump. You then run the other tubing back into the cooler. Fire it up and make sure it works like you expect.
  7. Now you need to attach the copper tubing to your fan screen. This is a simple process, just plan where you want your tubing to enter and leaveLayout Tubingyour setup and then start attaching it with the zip ties. I put about 4 for each circle for good holding power. You can also fine tune your coiling as you go.
  8. Once you’re done attaching the tubing to the screen you might want to build your self some outriggers for your fan. Mine was a bit tipsy to begin with so I cut up part of a 2×4 about 16 inches long and screwed to the bottom of my box fan.
  9. Reattach the fan screen with the original screws
  10. Now you need to figure out how you are going to get your vinyl tubing into your cooler. You’ll need 3 holes, 1 for the inlet to the copper tubing, 1 for the outlet and 1 for the pump power cord. I had a drill bit the same size as my vinyl tubing so it was a straight forward process, just make sure it’s in the lid or at the top of the cooler, obviously you don’t want water leaking out.
  11. Okay you should be ready to give her a try.

Operating the Air Conditioner

The completed unit in actionAlright you’re going want to put your fan and cooler in place, get your tubing cabled appropriately and you’ll want to get some form of pan or something underneath your fan to catch the condensation from the coil. Fill your cooler with enough water to cover the pump and then put in a bunch of ice. I used 3 bags to start. Turn on the pump and adjust the fan speed. Now bask in the coolness of your own evaporative cooler.

This sucker does go through the ice so you’ll want to do something other than buy hundreds of bags of ice. I took a variety of containers, yogurt, cottage cheese, paint buckets, etc and made larger blocks, they seem to last longer. Some alternate methods instead of straight ice are 2 liter bottles filled with salt water. They last longer and are colder than standard ice. You’ll just want to keep the salt water sealed so that you are not cycling it through your setup. Also you could use the freezer blocks that you can reuse. Good luck and stay cool.

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paul's wife 2009/07/29 at 9:43 am

Funny, all that is left now is a cooler full of water and you are off to work in your AC office. Think I’ll give her a real test and bring it down stairs where the kids and dogs are trying to lay low. I’ll give a full-fledged report after a sweltering day of abuse. Think we’ll pop out to the store and get a big block of ice….

Matt @ Financial Methods 2009/07/29 at 2:21 pm

This post makes me wish I was not in Florida, so I could actually try this advice! Maybe next time I visit my parents in upstate NY I will be able to give it a shot!
.-= Matt @ Financial Methods´s last blog ..Keeping Up may Set You Back =-.

Pam 2009/07/29 at 2:37 pm

Amazing. I’ve never seen anything like it and I’m from the south….
.-= Pam´s last blog ..Gluten Free Chocolate Desserts =-.

Justin Mckeown 2009/07/29 at 7:06 pm

Sensational work. If it survives, can you ship it down for the Australian summer season?

Kosmo @ The Casual Observer 2009/07/30 at 2:18 pm

Maybe I’m missing something (entirely possible) but wouldn’t the melt rate of the ice be directly proportional to the cooling rate? Hence the larger blocks would melt more slowly, but also provide less cooling power?
.-= Kosmo @ The Casual Observer´s last blog ..Thoughts from The Fundy Fog =-.

Paul Van Lierop 2009/07/30 at 2:55 pm

Kosmo I think you are exactly right as our testing goes, there isn’t the crazy amount of condensation that the ice cubes cause. You know I can’t be bothered to research the science behind this, I’m trying the brute force experimental approach.

Justin: if you don’t already have AC you should get some before we head down there to visit, I’m not bringing this thing on the plane, I might be spending some time with homeland security if I did.

[email protected] 2009/07/30 at 6:00 pm

Paul–You remind me of the Professor on Gilligan’s Island, all you need are some vines and a couple of coconuts and you can build a car.

You’ll be a valuable person to have around in the Apocalypse! (I’m linking you on my site, just in case) 😉

The Incidental Economist 2009/07/31 at 10:22 am

Back in grad school I lived on the third floor of a three-storey house (essentially in the attic). During the heat waves it could easily be over 90 at bedtime. I had no AC. Instead I would put a bunch of cooler packs on a cookie sheet and blast a fan over them, facing me. It’s the same idea as your set up only took me a lot less time.

Still, as a recovering engineering nerd I love this post.
.-= The Incidental Economist´s last blog ..Krugman Too =-.

Paul Van Lierop 2009/07/31 at 1:58 pm

Thanks for the love everyone Kevin I love the Professor reference. Thanks for the link!

Zot 2009/07/31 at 11:02 pm

“Okay technically it’s not an air conditioner it’s an evaporative cooler ”

Ummm, where is the evaporation. This is an Air Conditioner! You are using the ice for you cooler. An Evaporative Cooler uses evaporation (a process steals heat) to cool the water and the air/substrate holding the water (upto 20 deg F). What is a Swamp Cooler?

Funny about Money 2009/08/03 at 9:56 am

That is an awesome idea!

It’s very similar to the air-conditioning system we had in the 1950s and early 60s, when I grew up in a company town on the coast of the Persian Gulf.

The company had a central cooling plant. Pipes were laid underground extending from the cooling plant ultimately to each house in the camp. In your house, piping would come up and run through a big fan unit, which would blow air through vents into the structure. Water leaving the cooling plant was very cold. As you can imagine, the further from the plant your house was, the less cool your cooling system! We were on the far end of camp from this lash-up, so we got lukewarm air out of our fan. Better than nothing…but since my mother was a San Francisco girl, you can just imagine how much she enjoyed that. LOL!

Here in AZ, before the advent of air conditioning people used to lay a dampened towel in front of a fan, so that the air blowing through it would feel relatively “cooler” than plain air. Of course, it did raise the humidity level, but in those days the air was much dryer in the low desert than it is now, so it didn’t much matter.

In the early days of AC here, they had something called a “cooling tower.” I’ve seen them in the past, but think there aren’t any left anymore. It was a tall structure, about 15 or 20 feet high and maybe five or six feet across, built of wooden “fins.” Water was pumped to the top of this thing and allowed to trickle down through and over the fins. Evaporation caused the water to cool significantly. Then apparently air was blown over the water — or possibly over piping carrying water or some other compound and cooled by the evaporating water?? — and blown into the house. People say it was as effective as a freon HVAC system, and much cheaper to operate. It would be interesting to see if a modern-day engineering nerd could figure out what these things were and maybe revive and adapt the technology to today’s needs….
.-= Funny about Money´s last blog ..The Carnival of Money Stories =-.

Feaf 2012/05/30 at 1:25 am

Nuclear power plants still use that method the things you are calling fins are called baffles :P.

Jake 2014/12/23 at 6:58 am

I’m live here, in Dubai, and the system of underground pipes carrying chilled water you had mentioned, is catching on. It’s termed “District Cooling” and is designed to serve a fairly large area, based on population density. At one end of an area sits a structure carrying several of these Cooling Towers which chills the water to a temperature of 6 – 8 deg C, which is then pumped via insulated pipes to various homes in a particular locality. Air is blown over the pipes and heat transfer effected, bringing the desired cooling of the interiors.
In the past 4 years, I have seen this system fail just once- due to a pipe fracture, and loss of water. Imagine my surprise when the Engineers who were brought to repair the system turned out to be Americans!
This system is more cost-effective when compared to individual window-mounted or split AC systems. There’s no Freon or Ammonia involved, and there’s very little noise or vibration, too. However, when the ambient temperatures, esp during the Summer months touches 45 – 50 deg C with humidity hovering around plus-90% all day long, the district cooling system does seem to come under quite some stress.
But, touchwood, the system has worked fantastic!

Matt SF 2009/08/03 at 10:04 am

Boy this takes me back.

Freshman year, September humidity in the South, a free ice maker at the end of the hall, and lots of engineering students with too much time on their hands.

Hope it cools down for you guys in the Northwest.
.-= Matt SF´s last blog ..Best Reads of the Week: the Inconvenient Truth of the Health Care Debate Edition =-.

paul's wife 2009/08/03 at 10:41 pm

okay, so the Washington State heat wave is almost over. I can vouch that the homemade air condtioner did, in fact, work. I can’t say that we could realistically use it all day long (unless we had access to a couple dozen blocks of ice), but to cool down a room for a couple of hours it worked well. We used to cool down the bedroom and then a few times to cool down the “rec” room in the late afternoon/evening. It goes through the ice like crazy, but it was desperate around the VL household. I’ve been in Washington my whole life and never experienced more than a week’s worth of 90-100 degree weather. All we have is a box fan and an small window AC unit in our kids’ bedroom (kids sleeping is a top priority here). I’ll admit that my box fan now has copper all over it, but at least it doesn’t tip over quite as easily! Good job, husby!

faruq shuaib 2009/08/12 at 12:20 am

i have pretty appreciated the data that i have got from your website about the air conditioners its really very priceless . i hope to pass that to my art class since art emphasises creativity i shall really be gratefull with what you have done and am looking for more informations from you ,you can contact me through my e mail address.
thanks faruq shuaib
uganda ,kigumba secondary school

paul 2009/08/12 at 8:59 am

Faruq, if you would like to contact me directly you can go to and ask whatever questions you want or if you want you can find me on Twitter at @FiscalGeek

Tiger 2009/08/20 at 1:37 pm

Heres a new question for u Paul…approx. how much do u and ur wife make a year off this website with ur Google Ads? Obviously, it must be sufficient enough to keep dreaming up useless stuff like this in the hope that some suckers will read it not realizing that, in doing so, they are making u incrementally richer!!! Bluntly put, the time, energy and expense involved in duplicating ur “experiment” far outweighs the cost of simply buying a cheap portable room a/c unit, such as those actually advertised on ur own site, not to mention the difficulty of keeping enough ice around for that purpose. After all, thats why freon or refrigerant chemicals were invented in the first place, so u could have an self-operating a/c system without any need to keep adding ice!!!!

Just my $.02

paul 2009/08/20 at 1:45 pm

Tiger, if you think I am getting rich from Adsense then you’ve bought into the millions of ebooks out there. Honestly speaking I’m a geek. I would have made this whether or not i ran a blog that made a few bucks a month, it about covers my hosting fees fyi. I never said this was particulary practical, I just wanted to document my own crazy experiment. Curious as to what actually drew you here in the first place if you weren’t interested in such things yourself. Thank you for commenting nonetheless.

MaliceAlice 2009/08/26 at 4:45 pm

@Paul. I’m going to assume you’re not from Seattle, otherwise you would understand that buying a 250$ AC unit that one MIGHT use 3 days out of the year is a ridiculous suggestion. Also, wow, bitter much?

Casey Parker 2010/06/25 at 7:11 pm

You, sir, are a douché. 🙂

Casey Parker 2010/06/25 at 7:12 pm

Tiger. That was directed at Tiger.

james 2010/07/09 at 5:39 pm

wow tiger u are a douche ! i have a roomate that tried it here in oregon and he said it work really well! he said that it brought the temp down 15 degrees wich is really effective for something so simple. counter to the idea of keeping that much ice around would cost is countered by putting water in bottles and the freezeing them over and over agian instead of letting a block of ice melt. plus y ru concerned how much these people make! it really has no relations to this whole experiment.

Jony portable air conditioner 2014/07/12 at 8:45 am

Grate article. Thank for sharing.

MaliceAlice 2009/08/26 at 4:46 pm

Arg, I meant @Tiger. Rant fail. 🙁

paul 2009/08/26 at 4:50 pm

I was going to say MaliceAlice I hope I don’t come off as all bitter, sarcastic yes, but bitter no. You bet I’m a native but again I’m assuming you were targettting Tiger. I just might have paid $250 for an AC unit during the heat, I don’t cope well with that. Snow great, 95+ no thanks.

jo 2009/09/19 at 7:45 am

The whole set up is quite interesting and creative, to boot. I’ve seen things that are essentially not much different than this displayed as art. Paul, are you a closet artist?

I enjoy seeing people trying to solve problems in creative ways. With all the available consumer goods, often we buy solutions that are way beyond what we really need, and a lot less fun. You just can’t beat the pride of making something!

paul 2009/09/20 at 9:43 pm

I have been accused of many things but a closet artist is not one of them. Thank you for the kind words, it was fun to make entirely unpractical in the long run but fun nonetheless. It’s resourcefulness I value above frugality, cheapness, whatever you might want to call it. Thanks for reading and hope you check back often or subscribe. I promise this won’t be my last, Christmas is coming after all and I’ve got all sorts of crazy ideas in mind. 🙂

chrisoula 2009/09/19 at 10:05 am

I have no idea how I stumbled upon your site but keep up the good work! Highly entertaining! I built a lens for one of my cameras last month out of a plunger (can’t take credit for the idea, found it of course on the net) and some basic home depot odds and ends. So much fun. Now I know that 50% of the stuff that I make at home are just for fun but there have been those few items that work just as well as their very expensive counterparts and I love using when I’m on a shoot. Yes, it would have been a lot easier in many cases to run out and just purchase what I needed and be done with it BUT I would not have been able to make it myself! It’s all about the fun….guess you just have to find entertainment in challenging your own creativity and ability. Great ideas!
.-= chrisoula ´s last blog ..Greek Festival =-.

Bebe99 2009/09/30 at 3:47 pm

Swamp coolers are popular here in the desert Southwest. Though usually they don’t cool the water first, and don’t work too well when it is humid outside. However, cooling the water, as you have done, will mitigate this problem. A nice solution for a few days of heat!

Phil | Best Air Conditioner Reviews 2009/10/02 at 7:29 am

This is a great little project, Paul! I’d love to see you mod this system into a swamp cooler, just by building a towel on a conveyor belt of sorts and having it dip into the cooler filled with water. Something I’ve been thinking of doing in my spare time, as well. People need to realize it’s not necessarily the functionality or overall efficiency of the end result, but the fun of taking on the project!

Gloria Holes 2009/10/08 at 1:50 pm

can i use coolant or antifreeze like for cars instead of water?

paul 2009/10/08 at 3:50 pm

I would definitely not. You don’t want Ethylene Glycol flowing around in your house unless it’s in some form of closed system which this is definitely not. I also couldn’t tell you how the pump would react to that.

Tommy 2009/10/12 at 11:34 pm

Okay. So it’s been a while since you lasted posted, Paul. This reminds me of a design in college that I came up with. I just mounted a bucket above my window for the ice and had the cold water drip down a slotted towel in front of a fan into another bucket. I would dump the water from the lower bucket into the upper for a refresh once a night. I was stuck in a Texas dorm during a remodel in August (preseason), so a few degrees made my dorm room very popular. Now living in Mexico where electricity is expensive and unreliable with high drain, I’m thinking about using a similar design.
So, my question is: any new info before I make this? Have you ever tried Peltier Cells?

paul 2009/10/13 at 3:55 pm

Hey Tommy. I really didn’t do much more experimenting past this first model. Our weather quickly cooled down, Seattle’s only hot for a bit. If you’re looking for a longer term practical solution I don’t think mine’s the answer. For short bursts works fine. No I haven’t dealt with Peltier Cells at all. If you do go a homegrown route shoot me a picture I’ll throw it up as a readers ride so to speak :-).

Financial Samurai 2009/10/16 at 9:20 pm

Paul – This is hilarious and awesome! Living in SF, the average temperature here is 64 degrees and gets down to about 50 on average during the winter. It only gets up to 80 like 1 month a year MAYBE, so I haven’t had the pleasure to use AC.

Maybe I can create something like this back home in Honolulu!
.-= Financial Samurai´s last blog ..You’re Rich And I’m Rich, OK! You’re Still Rich And I’m Not As Rich, Not OK! =-.

Ed/ HVAC Professional 2009/10/17 at 1:34 pm

Interesting experiment. Not to be a wet blanket or dampen your creative spirit; I’ll offer a few thoughts. It is NOT an evaporative cooler. What is….it’s a homemade chiller. Evaporative coolers use the heat absorbing affect of water evaporating to cool the air and do not work in humid areas. Commercial chillers use mechanical refrigeration to cool the water; you’re using ice. Ice created from salt water is not colder than fresh water ice. Both are the temperature of the freezer they came out of, typically 0 to 5 degrees F. I think there may be a tendency to think this is “free” cooling; don’t forget there is a very real energy cost to freeze the ice. I would have to assume it costs much more to operate due to the inherent inefficiency of a home made system. You can by a 5,000 btu window unit for $89.00. and as a matter of comparison( I’ll round up a bit for convenience) a 6,000 btu window unit, a half ton unit, would be equivalent to melting 42 pounds of ice per hour. A ton of cooling is equal to 2000 pounds of ice melting in 24 hours. 2000 divided by 24 equals 83.3; cut it in half you get 41.65 pounds. A two bag of ice goes for about $1.85 in New Jersey. That’s about $38.00 an hour to run this thing.

A fun experiment to be sure. But that’s all it is. Support your local Wal Mart… an air conditioner.

[email protected] Heat Pumps 2009/11/19 at 9:05 am

Very interesting project. I suppose it is a very cheap way of creating cool air in your home, however, if you dont be carefull things can go wrong. I personally would buy one of the new generation heat pumps that are available from some great manufacturers. Not only are they alot cheaper than they used to be, they are also ver energy efficient and will almost certainly help to reduce your energy bills.

TJ 2010/02/05 at 2:22 am

Wow. Seems like alot of time and energy to make the thing and then alot of ice to run it. But it did pass the wife test! Kudos Paul. Cool idea.

Chicken Pens

Chicken Houses

siva 2010/02/11 at 10:56 am

wow its simple i like it

Gary Mic 2010/03/04 at 7:28 pm

Just a crazy thought if not looking to make this portable. What about the idea of digging down several feet and use the geo-thermal properties of a constant cooler temperature to circulate the water? could make for lessening the need to chill water! Or better yet, using well water?

paul 2010/03/04 at 8:06 pm

I like the way you think Gary. I’m not on a well so that’s not an option but I know others have used that exact method.

jm 2010/03/15 at 10:39 pm

so hot in here in the philippines, gotta try it. hah

nelson tragura 2010/03/17 at 6:59 pm

Yep. Heat wave has affected the entirety of Cebu, it caused me migraines.

TJ 2010/04/06 at 10:25 am

Oh well, I guess I’m not original! I was sitting thinking about how to create one of these things, and this exact image popped into my mind. Curious, I googled the term “home made air conditioner”, and viola… this is one of many designs. Oh well, so I’m not original. The only difference is I won’t need a pump. My e-cheapo landlord wants a small fortune from me for running a single A/C. So, I’ll be connecting my little A/C unit directly to the water supply, which has a flow of approx. 300 gpm (I’ll run it at half-flow), and a water temp of about 60 on the hottest days. No pump. No cooler. Very much like an apartment washer. Too bad for the landlord (and his well pump). His greed is his problem. I’ll stay nice and cool free of charge. (Electric and water are both included in my rent… no prob there.) 😀

Mandar 2010/05/12 at 11:27 pm

This idea and its implementation is really cool! In India, where i live, temperatures are hovering around 41 deg Celsius, and natural cooling does not start till 10 PM in the night. I was looking for some idea to cool down my apartment in a non-costly way, and came across this site. Well, i inquired in local hardware shops about copper tubing, but they have none.. so looking for other options at present. Paul could you suggest any ?

Kyle 2010/05/18 at 7:13 pm

Would dry ice work in the system? I mean the sublimation of dry ice just goes straight into the air and it’s not toxic.

paul 2010/05/19 at 1:01 pm

Kyle, I’m afraid I don’t have an answer for that but if you try it please share with the rest of us, it sounds reasonable to me. As it stands the ice water cooler takes a lot of ice to keep pumping out the cold air.

one timer 2010/07/04 at 3:07 am

do not use dry ice for cooling…it is carbon dioxide and using it to cool a room will suffocate you, in addition, it will definitely cost more than its worth… toxicity is not the problem, but the displacement of breathable air is…

Chris Brooks 2010/05/19 at 11:00 am

You must be reading my mind. I’m wanting to invent some type air cooler for my 1400 sq shop and I wanted to know about dry ice also. Seems that you could close up the dry ice and it would not evaperate? Let me know what you find out.

I was going to build a box 1′ wide 3′ high with the copper coils in between and pumped from my well water. My well water is very-very cold in in Macon Ga.

Chris Brooks 2010/05/19 at 11:13 am

Also on the subject of well water and under ground piping, I haven’t tested it but this is my thoughts. Make a box with copper piles like the one above. Pump well water thru it underground to your box maybe under your home. The box would be inline of your duct work with push/pull air. You wouldn’t want your pump to run all the time, but when your water temp reached a set temp like 80 degrees, open the outlet to allow the water to flow turn, causing the pump to come back on when pressure drops. When the water temp hits say…60 degress, cut off the valvue. What you need to do though is make sure your return water goes back into the pump shaft. I wouldn’t think you would want the water to run in the yard, etc.

Tony 2010/05/25 at 8:13 am

Sounds like a good plan, especially if you want to create something on the cheap.
Problem here in the UK is getting hold of enough ice. It reached 88 here at the weekend, and most homes don’t have air conditioning. Most don’t even have fans!

Kyle 2010/06/06 at 5:04 pm

Dry ice works well with the system. It does bubble in the water, it kinda sounds like a jacuzzi, but i can’t really hear it cuz my pump is so damn loud lol. However i should note that it is dangerous to use too much dry ice in a small area because, while non toxic (Dry is just CO2 it is CO that is toxic) it can displace the oxygen levels in the air. Just a small block should suffice.

hojo70 2010/06/17 at 4:20 pm

I built one of these the other night. Have a 145 gal/H pump with a cooler full of ice water. Set the thermometer and came back 45 minutes later. The room was 3 degree warmer. I dont know who started this internet hoax but save your money and just buy a real air conditioner – these DONT WORK.

John 2010/06/18 at 2:35 am


You need to follow the instructions carefully. Maybe something isn’t at the right place. You should check it carefully before you make a conclusion. I believe Paul do have a great idea about economical air conditioner and I looking forward to build one in the future. You’re a genius Paul. Keep posting…

Chris Brooks 2010/06/18 at 5:24 am

I have well water close to my shop and I’m building a casing that will involve twin Chilled Water Coils, one at the receiving end, a fan in the middle and a 2nd coil at the other end. I’ll pass very cold well water thru both coils and when the water reaches 65 degrees, I’ll open a valve to allow the well pump replinish the water supply. It’s the same princple except I’m ducting my cooler as a central air unit.

Financial bondage 2010/06/28 at 3:18 pm

Unless I missed it, I don’t see any mention of what this thing cost to make? Very cool. I like it!

Winnebago hire 2010/06/28 at 3:56 pm

Winnebago hire IS THE MARKET LEADER in the rental of Winnebagos for TV, Film

Winnebago hire 2010/06/29 at 1:46 am

This is some nice work. Thanks for sharing, and I look forward to more writeups to read in the future.

Josh 2010/07/02 at 3:08 am

Man, this stuff is awesome! This world is in need of some serious geeks like you! Hats off to you!!!!!!

Winnebago hire 2010/07/08 at 4:30 pm

Many thanks for this article… it was a great help.

Chris 2010/07/20 at 11:41 am

Heat exchanged between the water and the ambient air will eventually bring the ice/water in the cooler to equilibrium and you’ll just have a cooler full of warm water…. and a fan running.

You might be able to see how much energy is in ice by calculating the weight of ice, it’s temperature, and the weight (or amount) of water in the cooler, and it’s temperature.
Then remember that 1BTU is the amount of energy needed to change 1 pound of water 1 deg fahrenheit.
And if you’re using your fridge to freeze the ice, and your fridge is in the house, exchanging heat into your kitchen’s ambient air…. you should probably just buy a regular air conditioner…

Winnebago hire 2010/07/30 at 7:59 pm

Thanks so much for the great post and filter information.

Todd Bailey 2010/08/17 at 11:35 am

I don’t understand people, I saw a stack of a/c’s at the home depot the other day for under 80 bucks? Why futcz around with some home made thingy when you can have the real macoy?

Casey Parker 2010/08/17 at 12:44 pm

… because $80 isn’t pocket-change to everyone, you ignorant jackass. 🙂

Todd Bailey 2010/08/17 at 1:51 pm

Casey, you are the ignorant jackass.
I see a fan that retails for $20 and the coil of copper that easily retails for $30 then there is all the other hardware that you need to purchase then assemble it. All of a sudden that 80 dollar A/c that you don’t have pocket change for is cheaper than this hack job. DO YOUR RESEARCH but making a complete idiot out of yourself..

Casey Parker 2010/08/17 at 2:26 pm

Most people already own a fan, and probably have for a very long time. If you live in one of the cooler states, e.g. Washington, you have no reason to buy a full A/C when you normally just need the fan, and the electrical costs completely outweigh the usefulness. Have YOU bothered to research beyond the cost of the initial investment? If you do, you’ll notice that the $80 unit you’re talking about could barely reduce the temperature of a single bedroom.

So, I reiterate … YOU, Todd, are an ignorant Jackass. Also, apparently arrogant.

Todd Bailey 2010/08/17 at 3:16 pm

You are such an Asshole, I can’t believe it, where do you people come from?
Did you take a special class in elementary school? Or have you alway been a closed minded person?
I make a simple comment that considering the cost to build this thing compared to purchasing a tested technology, some idiot would spend over $100 to build this than install a low cost a/c unit. Are you so insecure that you have to attack someone who has a better understanding of hvac systems and how the physics and science of heat transfer systems actually work? Yes many people do have fans, but it’s a drop in the bucket compared to the cost of the other items needed to build this thing. And this thing won’t work, there just isn’t enough surface area in the coil to have much effect.. Google evaporative “swamp” coolers and look at the design specifications.
This project would be fine for a junior hi school science fair project to demonstrate thermal dynamics and heat transfer, but for all practical purposes, it won’t cut it trying to cool much of an area with any serious air flow.
fwiw, I do live in one of the “colder” states, Seattle btw. And during our three weeks of hot 95 + degree summer, an Air Cond. is not what I’d consider optional equipment. Fans are ok when I want to draw in the cooler night air, but blowing around hot air during the day time doesn’t cut it.. My place just has too much exposure and too little insulation. Something I plan to fix some day. Yes I do pay a bit more in electrical consumption, but that’s the price of doing business.
I have a 12×24 ft media room and between the sun’s heat and the equipment, my little $80.00 special a 5,000 btu a/c does just fine. Between the sun and equipment the room would quickly overheat in the confined area with out it..
For the rest of the house the 24,000 btu unit takes care of the task.
Anyway, I don ‘t know what your problem is, but I’m done talking to you about anything.

EUGENIACohen 2010/08/23 at 9:31 pm

Make your own life more simple take the business loans and everything you require.

Kellee 2010/10/04 at 2:59 pm

The big picture:
If the ice is frozen in the refrigerator in your kitchen the overall home temperature will be increased not decreased. The refrigerator that is making the ice will increase the total heat in the kitchen more than the total heat remove at the site of the “Air conditioner”. All the energy used to freeze the ice becomes heat in the home. You could move the refrigerator outside and eliminate this problem which is why a normal air condition has the coils outside.

With that said, it’s a fun project and will of course will cool the spot it is placed at after heating the spot that created the ice. The Fun of building it and watching it work is probably the best reason to do it!

TruCool 2011/04/04 at 5:47 pm

Hey! Please take our survey. We are a group of students at Boston University and we are working on a product similar to this one. We would like your feedback and answers.

Please take our survey!!


LC 2011/09/07 at 10:58 pm

Awesome!! I just made one of these today.. I was actually copying another tutorial, but yours seems to be the most detailed.

Total the project cost me about $5 for the foam cooler/ties/etc, $20 for the tubing, and $30 for the pump. I live in Washington so I only need to use this maybe a couple months out of the year tops, so it’s a lot more cost effective than a portable AC unit.

I ended up using 1/4″ copper tubing instead of 3/4″, I wonder how much difference it will make? I assume the GPH of the water pump is more significant? Not sure.

LC 2011/09/07 at 11:00 pm

To clarify my question..

GPH of the water pump is more significantly relevant to cooling than the copper tube sizing? Or are they both fairly significant factors? I was afraid if I got too big of tubing: a) It would block too much air for my fan (mines grated heavily) b) it would hit the fan on the inside

After testing, I don’t think 3/4″ would have done either of those, but not sure if it’s really worth another $20 investment on tubing to see if it’ll be more effective.

RB 2011/11/28 at 3:29 pm

Probably an old car radiator would make a good heat exchanger?

carl 2012/02/13 at 6:49 pm

what about running the water through a refrigerator or freezer, being sure to seal both the entry and exit points? That way the water is being cooled by a source that you are already powering for another use anyway so that you don’t have to pay for the ice and deal with the clumsy looking cooler.

Reply-er 2012/08/07 at 5:54 pm

@carl – the short answer is: yes it will work technically; but fails in practice.

Kellee also briefly explains why as well. Consider an enclosed space in a room (controlled environment). Place one freezer in the room. The freezer converts electrical energy into mechanical energy when compressing freon. The compression stage generates heat as gas molecules collide. This is heat is convected outside of the freezer through radiator grills. At the same time it slowly releases compressed freon into a vacuumed pipe array (condenser). In the condensation stage, the drop in pressure (collisions) brings the freon to a very low energy state (chilled). Thermal equilibrium then dictates that what little heat (energy) within the enclosed freezer space exist, shall be attracted to the lower heat (energy) level of the condenser tube array. The freon is recycled again by the compressor and the cycle continues.

With both freezer space and room space starting at temperature=y at t=0, at t=x a basic expectation is that the freezer temperature = y – c and room temperature = y + c. (In reality there will be more heat generated; as the entire system does include energy as electricity being supplied)

So, following the logic of eliminating the ice and icebox by direct linking the coolant to the source, couldn’t you also eliminate the fan and just leave the freezer door open? Ha ha. And we all know that doesn’t work. Wouldn’t it be funny though? If the solution for global WARMING (anthropological or not) is to turn off all COOLING systems.
In conclusion, you would not want to run a cooling unit in its own byproduct.

carl 2012/08/07 at 9:33 pm

I was thinking of running it through a freezer I have sitting out on the back porch.

Reply-er 2012/08/09 at 7:30 pm

In reply to ‘freezer…back porch,’ assuming you have an insulated venting medium then yes, it will work technically. However, be careful not to overrun your freezer components. Remember the Simpsons episode where Homer created a refrigerated tent during a heat wave? The cost of a new freezer may be greater than a new AC unit.

sircious alska 2012/04/09 at 11:40 am

can u help me on how to connect the pipes with the cooler and the pump. and if u can help me with picture of the pump i wil be glad and greatful. pls i need am answer via my email bcos this is the secnnd time i am posting without answer.

carl 2012/04/09 at 3:13 pm

i asked why not run through a refrigerator or freezer and nobody answered me….

John 2012/04/26 at 1:31 pm

Great idea! I would like to build one of these to cool the back of my van on camping trips. Since my unit will have to run on 12v power from a portable battery pack, I’m wondering if it would be more efficient to run the copper tubing in vertical lines, from top to bottom, rather than round and round? I’d like to be able to use the smallest pump possible.

Question 2012/05/22 at 10:22 am

I got the idea from the article and comments with Car Radiator / Heater Core with Sea Water, with 12 Volt DC .

Feaf 2012/05/30 at 1:28 am

I am wondering if it is efficient to make a antifreeze based system. In my design it will work exactly like most modern AC’s it will transfer the heat from the air to the antifreeze then cool the antifreeze using a heat sink with another fan on it in the back in which the antifreeze will be pushed through by some copper tubing and a beefed electric sump pump
modified to run as long as it is getting power rather than having to be submerged.

panda 2012/06/03 at 2:20 am

please serch snowbreeze ice cooler

klay 2012/06/11 at 1:49 pm

wow. me and my friend made some of these for our fish camp when i was younger. they were slightly different but same concept. im from texas and even with the humidity they make a HUGE difference. people who live in less humid areas then where i grew up sometimes dont understand that although humidity is a really lbig factor in how hot it gets, its the same with the cold. and turning the air temp from hot to cold makes it really nice no matter how humid it is. way to go Paul for bringin back the best a/c ever.

Jared 2012/06/17 at 3:44 pm

How much this would cost eventually, summing up the cost of the pumps and all the components?

CJ 2012/06/20 at 11:34 pm

@Jared – The parts for mine cost about $90 total. The pump was the expensive part ($30), believe it or not, and the copper wire was a bit too. The rest of the items are all fairly cheap.

hnstcntryboy 2012/06/28 at 12:50 pm

Great fantastic idea!! You have now earned the “redneck build it award” lol!! Now being a true redneck i’ve had this idea for some time. Though on a different scale per-say and for a much different use. I am building something of this nature for tent use(camping) using solar powered everything!! Solar powered fan, solar powered pump, and your pumping the cold water through a coil system does make sense. And thankx now I can adjust my (ugly) prototype and try this!!

handyman2know 2012/07/01 at 8:48 am

I once air conditioned a pick-up cab using ice and a fan. I dumped a few bags of ice into a cooler then rigged a small dash fan to blow the air across the ice. It kept the interior tolerable for awhile before the relentless Texas heat nullified it’s effect.

I wouldn’t bother wasting time nor money on this contraption. You’d be better off buying a small window unit that included a heating element so it’ll have a dual use. There’s also A/C units that are portable free-standing units that can be moved from room to room to suit your immeadiate needs. These devices work much better using less electricity to boot.

scott terhune 2012/07/08 at 3:09 pm

Paul, being a geek myself, or mechanically inclined if you will, let me explain, that this is indeed an air conditioner, using ice water as coolant, rather than freon. a water cooler simply blows, or sucks air through water. im about to build an a/c out of scrap car parts. theoretically, it should work.

todd bailey 2012/08/07 at 6:22 pm

This thread just spawned an idea, transferring heat from the house into a hot tub.
The idea is to transfer summer heat from the house into the hot tub by using the “radiator coils” at a heat transfer mechism. If the hot tub is already at temp transfer the heat to some form of storage module…

Wonder how well this might actually work…

Mike 2012/08/09 at 7:22 pm

I made one of these using this website as It works ok at best. I wish I wouldve gotten a pump with 2 outlets to support a double coil on each side of the fan. Problem with that fans generally have an exposed motor in the back. Still with what I have its cooler air than normal. I use it in the garage which is already pretty hot so its tough to tell a difference.

todd bailey 2012/08/09 at 7:54 pm

Seriously, when you consider the cost of a 5000 btu window mounted a/c being not all that much, why bother with this hack?

handyman2know 2012/08/10 at 9:44 am

Ya’ll need to check out Port-A-Cool’s website for evaporative coolers that can be transported from room to room. You may be able to get a glimpse of it’s inner workings so you can cobble together something similar.
As for using a refridgerator, a buddy uses a side-by-side with auto a/c evaporators hooked up in series inside the freezer with tubing coming out of the side to a car radiator mounted in front of a box fan. He uses a 110v small pump to circulate the antifreeze mix thru the system and keeps gallon jugs of frozen water inside to help keep the temps down longer while the unit is in use inside his converted garage/game room. It works very good!
He bought the radiators at a scrap yard except for the pump which was found at a pawn shop. The rest of the bits were sourced from Lowes.During the winter the heat thrown off by the refridgerator does a decent job of heating the room, too.

David Cummings 2012/08/28 at 8:03 pm

Good idea. What about this? Use fridge as the cooling unit. Drill two holes in the side of the fridge, one for inlet, one for outlet. Have the copper tubing coiled (many times) in side the fridge to “catch” the “cool.” Pump water through the tubing slow enough to allow it to cool down. Insulate the tubing once outside the fridge (to keep the cool till it reaches the fan) where it is now naked and radiating the cool while the fan blows it throughout the room needing cooling, again, insulate the line until it reaches the fridge where the cooling begins again and recycles again. NOW…you will pay a higher electric bill due that the fridge will work overtime attempting to keep the interior cool. This process is similar to digging a deep hole, burying pipe and recirculating the air. Imaging living in cave country. Caves generally stay +- 55 degrees. Run a pipe down there and recirculate the air in the pipe going to your living space. Oh yea, if possible, attempt to vent to the outside the hot air created from your freezers and refrigerators in the summer, capture it in the winters. David P.C.

Charlie 2012/09/04 at 11:46 am

I read your article about your homemade air conditioner after building one of my own. The differences are than I am using a stand-up fan rather than a box fan, and I am not using a pump, but rather siphoning the water from a five gallon bucket (not insulated) into another bucket. I am keeping the water as cold as possible by having an ice block in the bucket at all times, so I know water temperature is not the issue (unless it needs to be frigid). The bottom line is that, while I can tell the breeze from this unit is slightly cooler than the breeze from a normal fan, it really doesn’t seem to be cooling my room down very much, which is disappointing. Does the room temperature need to be more than 85 degrees to see a difference? What do you think could be the problem here? I have copper coils on both the front and back of the fan.

tanveer 2012/10/21 at 1:35 pm

hey Mr. Paul…m making ur so called AC in my project..
so i need ur little help..
can u plzzz tell me it advantages and dis advamtages..
plzz mail me in [email protected]

Lodu Lassan 2012/10/31 at 5:02 am

Chootia kay bachchay …..

rckolus 2013/05/28 at 5:57 pm

Hey I’m interested in building one for my room, but I’m not sure how effective it will be. Do you have any “before and after” temperatures for the device?

Warren A.Jacobs 2013/07/04 at 10:27 am

If you are making your own ice you better have your freezer located outdoors. Otherwise this device is HEATING your house. The laws of energy conservation are hard to bend

Khorgan 2013/07/06 at 11:38 am

If you had a deep freeze unit (or simply a large enough freezer section) you could rotate frozen 20-oz bottles of water. Thank you for sharing your idea.

Bhahbh 2013/08/05 at 2:02 pm

Which works if you only need this for a short time. If you’re planning to use this idea for a long-term cooling device, you’re wasting your energy in multiple ways.

the way cooling works, you’re moving heat from one place to another via some medium – air, liquid, or refrigerant.

This plan is regarding a chiller, where you introduce the air to a cold medium, the medium absorbs heat from the air, cooling the air – not a bad way to go. Other types are evaporative, where you use the heat of evaporation to remove heat from the air, and refrigeration, where you have a closed system that uses state change of a refrigerant twice (refrigerant is forced to go back and forth between liquid and gaseous states) to move heat from one location to another.

So by your suggestion, you would be moving heat from the bottles of water into the air inside the freezer. That heat is removed from the freezer air via a heat exchanger which moves the heat into the refrigerant. The refrigerant moves the heat to another heat exchanger, which moves that heat into the environment. So if your freezer is in your living space, you’ve now just moved the heat from your air, back into your air, and used electricity over and above to do so.

Again, not that it’s a bad idea for a temporary arrangement, but I wouldn’t depend on this for Texas summers.

a 2014/04/12 at 11:29 pm

Its good but there will a confusion that from what home made thing thus we pump in the water through the container

Stephen Black 2014/05/21 at 11:30 am

I am going to use a big bucket filled with antifreeze (not portable obviously) and then sink a few 2 liter bottles of water that have been frozen overnight into it. The antifreeze should help with the heat exchange and actually end up cooling better I think. If I used a 55 gallon plastic trash bucket I could freeze 5 gallon buckets full of water and drop one or 2 in at a time to get extended cooling 🙂 Wonder if something like veggie oil would work similar at a cheaper cost? Just thinking out loud, great write up ! Thanks.

DAVID LIVINGSTON 2014/06/24 at 5:35 pm


carlos rivera 2014/09/09 at 1:50 pm

hi i like chiken

Smithk5 2014/09/12 at 5:00 pm

I really enjoy reading on this website, it holds great articles. Don’t put too fine a point to your wit for fear it should get blunted. by Miguel de Cervantes. dkeffedkcffckefe

Audrey Miller 2014/10/06 at 11:33 am

Impressive! This is totally an amazing craft you did. People nowadays are getting innovative with different things and it’s pretty awesome. Summer is indeed the most liked season by everyone, this is what you called beach time. But staying at home when the heat strikes, is simply stressful. Good to know that there’s some smart invention like this one. Thanks for sharing!

Hymie the mime 2015/01/02 at 10:45 pm

This is great! I can host parties for kids bdays as well with my amazing mime tomfoolery! They always say cool off Hymie, he’s hot tonight! This might help with that as I am often unable to convince audiences that my heat strokes are not part of the act or a laughing matter!!:))

Andrew 2015/01/20 at 5:44 am

does this work like an evap cooler?

abraham paul 2015/04/07 at 5:59 am

i tried your experiment but when the cool water passes through copper pipe water drops comes from copper pipe. its not leak. it cuz copper pipe sweats,, any solution for that

Texas Ray 2018/07/14 at 3:57 am

I wouldn’t call it sweat because it’s due to cold, not heat.
It’s condensation from the humidity in the air that collects on the cold pipes.
It happens with all air conditioning systems and there must always be some sort of drain to get rid of such condensation.

James Norris 2015/07/01 at 9:34 pm

Technically this isn’t an evaporative or “swamp” cooler, as it’s a closed system with no evaporation happening. The heat is just being transferred from the air around this device to the back of the freezer you used to make the ice. I hope they aren’t in the same room!

Dwight Wright 2016/04/07 at 10:25 pm

This is a functioning AC unit (albeit, not as effective one). It is definitely cheaper than any other AC to build (I used a clear rubber hose from the pump to the copper and sealed with clamps so that no soldering was needed for my smaller pump). Here in Texas I paid about $50 for all my supplies. The cheapest AC is about $70. If you get re-freezable ice blocks and just keep rotating them, your actual savings come from the electricity being used vs. electricity from a conventional window unit or other.

Hell, I spent an extra $2 for a black box fan and used some black paint to color my styrofoam cooler a matching color and sexified my homemade AC. My first attempt (in my opinion) didn’t work, but I only tested it for about five minutes. I’m building another one to test for much longer.

My true experiment I’m researching is to use dry ice and see what happens. I know that you don’t want to breathe in a lot of dry ice vapor. I also know that you don’t want to keep dry ice completely sealed because the sublimation of the dry ice can make the cooler explode. So, I’m thinking make a tiny exhaust hole on the cooler for a very tiny negligible amount of carbon dioxide to escape to release the eventual and slow pressure when the ice turns into a vapor.

supun 2016/07/13 at 6:25 pm

The people create portable air conditioners.It can found on Etsy.Keep it appropriate on Garage or Dog-house.It’s not as cold as in house.But can get Significantly cold.That cold is enough for Garage or Dog-house.Buy it.awesome product!

Niyasa 2016/07/13 at 6:34 pm

This is a functioning AC device.Your actual savings come from the electricity used begin.Use it and Recognize the difference.This device has on Etsy.can you bought it.

Alexandra 2016/07/13 at 6:52 pm

I like it keeping on Dog-house.Because Dog-house are very Dry place.The dog-house create on Surrounded.Not come some fresh Air.Due to Reasons can bring a infections on dog skin.Due to this Reason needed Air conditioner in dog-house.I’m really recommended this unit.

Nalin 2016/07/13 at 6:58 pm

This gallon bucket air conditioner really like to keep garage/chiken or dog-house or your pet-house.This placess are really Hot place.Need cold this places.I’m really recommended this unit keep your pet-house or Dog-house.I’m sure Your pet Like it.

Chathu 2016/07/13 at 7:09 pm

This ice bucket air conditioner Cool my pupy’s house always.My pet pupy’s Like it.Because this conditioner come fresh cool Air.This device is portable.So very easy to use and very easy to keep in dog-house.I buy this unit on Etsy.I’m recommended It.

Texas Ray 2018/07/14 at 3:49 am

That’s NOT an evaporative cooler.
It is in fact a sort of air conditioner.
Your cooling doesn’t come from evaporation, but rather from ice that was cooled in your fridge.
Evaporative coolers work by pulling air through a water soaked medium causing evaporation which cools the air.
Your system forces air around pipes that are cooled by ice water flowing inside the pipes. Heat is transferred from the air to the pipes and finally to the ice water flowing inside.
No evaporation is taking place. Your water just gets warmer and eventually you have to add more ice or there won’t be any cooling.

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