Homebrew Air Conditioning
It was the summer of 2005, and a heat wave was sweeping across Ontario. At the time I was working on my engineering degree at the University of Waterloo, and tuition was just a little steep. As such, I lived in a cheap student house with no air conditioning. Fueled by a combination of too many engineering courses, too little money, and an overarching desire to not die of heatstroke before I graduated, I made my own air conditioner.
I put a few pictures of it on the internet, and then things got a little crazy thanks to Slashdot. I was featured on CTV’s Canada AM, had stories in The Kitchener-Waterloo Record and a few other newspapers, and was interviewed by a few radio stations including CBC Radio and NPR.
When you get down to it, it’s a basic heat exchanger, using water as the medium. You’ll probably need to fiddle a bit with the dimensions of the supplies based on your resources and preferences.
I’ve migrated this site a few times – first from the University of Waterloo servers, with their ever-patient admins, and then from a separate micro-site on this blog. This is my personal “blast from the past” that I’ve preserved for the sake of memory – it made for a rather entertaining summer!
Original Air Conditioner Concept
This is the first version of the air conditioner I made. Click on the pictures for more details.
 Geoff’s Original Homemade Air Conditioner |
 Heat Exchanger Improvements |
 Water Supply Improvements |
 Technical Notes |
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Final Design
This is the final design I settled on after fiddling for a while.
 The Black Beauty |
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Other Designs
These are some homemade air conditioners other people from around the world have made.
 Pete’s Homemade Air Conditioner |
 Anonymous’ Homemade Air Conditioner |
 Spencer’s Homemade Air Conditioner |
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Very nice, and cool of course, I’m trying some of these here in Brazil.
Thats amazing, I am sick of paying crazy bills, think I ll do the same!
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[...] I just type in “homebrew ac” to my Awesome Bar and hit enter, and it brings up the site I want. On a similar note, it even seems to find things that aren’t in my history, I assume by using [...]
thx bro my friend and i need the inspiration
[...] or a portable air conditioning unit, I decided to make an evaporation cooler based on designs seen here and here and [...]
Geoff, I actually made a version of this using a huge 20″ industrial fan with coils on the front of the fan. Unfortunately, no matter how cold or how much water i pumped through the coils, it always warms up about less than halfway through the coils before making it all the way through. I can hardly feel a difference in room temperature.
Does the size of the fan or fan speed have anything to do with this? Maybe it doesn’t work when the fan is too big and too fast? What I mean is the rate of cooling simply cannot catch up because the diameter of the fan is too big and the rate of air flow is too great.
Hi Joe – Yep, sounds to me like the fan is just throwing too much heat for the coils to deal with. The coils are actually from the very first version I made and are not nearly as efficient as using a radiator – especially in high-load applications such as yours. If you’re going to use a big fan like that, you need an equally big heat exchanger, and the coils just aren’t going to cut it. Try a local surplus or parts store.
hey geoff
awesome idea and i tried it.
the first time siphon worked and all was good.but then the second time the water refused to even rise up through the tubing plz help me quick.
Hi Kavjit –
Two important things to consider:
1. Is everything sealed perfectly? Any leaks will cause the siphon to not work.
2. Is the water outlet end of the siphon a few feet below the water intake end of the siphon? There needs to be a difference in height in order to drive the water through. See http://en.wikipedia.org/wiki/Siphon
hey geoff- thanks for the reply but i figured out an easier wy to start the siphon.
I fed water from the outside part of the vinyl tubing which then create a vccum inside the the tubing and starts the siphon in abt 20 secs.
Cheers, Im freezing
Kavjit
[...] Low-Cost ‘Air Conditioning’: Connect a coil of copper tubing to an electric fan, run cool water through it, et voilà, cool air. Use a DC fan, batteries, and a solar charger, and your costs are all upfront. [...]