Heat Exchanger Improvements
The major factor affecting the efficiency of the air conditioner is the heat exchanger. A radiator or evaporator coil would be ideal, but cost and availability are a concern. This page details my attempts to improve performance of my homemade air conditioner with minimal cost.
Strips of tinfoil were first used. You can see some of the copper coiled along the front, from an earlier attempt to improve the heat exchanger. This wins in the cost department, but ultimately the choice was made to discontinue the use of foil as it had the annoying habit of coming undone and buzzing like mad during the night.
The decision was made to completely revamp the copper coils, and install the entire length of tubing on the front of the fan. You can see the recoiling in progress, I did a bit neater job this time (but not by much).
Here’s the completed copper coil on the front of the fan. Cold water is fed from the centre to the outside. Again, I’m unclear as to what configuration if any (cold from the inside, cold from the outside) would lead to superior performance.
I decided to use wire to create a mesh on the front of the coils. (18 gauge wire, Radio Shack, ~$5 – I’m up to 30 bucks now!) This would increase surface area, intercoil heat transfer, and turbulence near the coils, hopefully increasing performance.
I first attempted to solder the wire to the tubing, a stupid attempt as the entire system is designed to efficiently transfer away heat. After several minutes of terrible cold joints, another approach was required.
I ended up weaving the wire from the centre to the edges, and back in. Approximately 10-12 passes were used per quarter section of fan.
Here’s a shot of the completed upper left quarter.
Weaving the wire is an unbelievably frustrating experience at times. The copper tubing usually has a slight gap between the white wire mesh on the front of the fan that the wire can pass through, but at other spots the wire will catch and start to unravel. It helps to have the proper tools (needle nose pliers, beer) to stay relatively stress-free. In this shot I’m halfway through weaving the lower right quarter.
Just be patient and you’ll be fine.
Here’s the fan as it stands right now. Saturday went from evening to night, and that means I need to go somewhere with cold pints and hot women. I’ll complete the remaining quarters tomorrow when I have a bit more time and patience.
Preliminary tests are very satisfactory. The cooling rate has increased, and the room will get a bit colder as well. This will help in extremely hot situations, where heat would leak into the room as fast or faster than the system could remove it.
| Homemade Air Conditioning Plans and Pictures | ||
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Original Design Geoff’s Homemade Air Conditioner Heat Exchanger Improvements Water Supply Improvements Technical Notes |
Other Designs Pete’s Homemade Air Conditioner Anonymous’ Homemade Air Conditioner Spencer’s Homemade Air Conditioner |
Final Design The Black Beauty |
TU É MUI DOIDO O BROTHER!!!MAS DEVEFUNCIONAR ESSA PARADA VAMOS TESTAR OK!!!!!!!!!DU BRASIL/RIO/CABOFRIO..OCEAN FRONT WALK!!OK
Hah! Nice.. I need something like this in my computer room. Does it even get hot in Canada?
how many degrees cooler are we talking about? is it worth the effort?
Hi Joe,
I`d go straight to the heat exchanger detailed here – drastically better performance than any other option I tried!
im having troubole understanding how your getting the water to run threw the copper piping from a cooler of cold ice water, how does that work?
Hi Drew – The water runs through the pipe via a siphon effect, a pump, or external pressure from a water supply such as the garden hose.
Check out Spencer’s air conditioner for an example of one that uses a pump.
whether this type of design is eligible for cooling the car or not
Canada boasts some very fine engineering schools. You appear to be a prime candidate! How are your math skills? Computer skills? You seem to have the ingenuity and creativity to qualify!
Could you help me? Where is the pump that you used for the thing?
It’s been hell trying to find a cheap water pump.
Best approach is a simple aquarium pump – can easily be sized for your application.
Hi Geoff,
I just stated reading about homemade air conditioners 30 mins ago so bear with me. What about the option of using the main plumbing of your house to send the water through the radiator or coils and then run it right back to your plumbing so you are not using any water during the process, besides the fact about this being safe, would could water be enough to make a difference or is ice requires?
Hi Sean,
The performance would likely be great if your incoming water supply is cold (ie groundwater sources are ideal). The only concern would be contamination as a radiator and tubing are not ideal ways to transport drinking water. It would be best to treat it as “grey water” and use it for gardening or similar.
Thank You for this information. I wanted to do something like this for my dogs (and me) as inside house temperatures are now reaching 105 degrees F. It is unbearable to say the least. My Dad had made a tiny swamp cooler from a bird cage but that was so long ago I just can’t remember how he did it. You have saved us!