How to make a home made air cooler?

I want to cool the air inside the cabin of a my boat but I don't have room to install even the smallest of air conditioners.  I would like to build something like a swamp cooler (Evaporative Cooler) but without the evaporative part.   I don't want to blow additional humidity around in the cabin.  I can use a pump to get a never ending supply of cold lake water.  I'm wondering if putting a fan in front of a radiator cooled with lake water will give me any sort of a reasonable deltaT on the air flowing through it?  Basically using a radiator in reverse.  Anyone have any thoughts on if this works? what kind of radiator to use?  and if I can get any reasonable temp drop on the air going through the radiator? 

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CrackKills (author) 5 years ago
Wow. Thanks for all the responses. Lots of good ideas. Vyger this is exactly what I was looking for. I think at the peak of summer my incoming water temp will be about 66-68 on the lake but the air can be 90+ in my area. Based on what this does for your space I'm going to try it for my boat. and I can custom fit it to what ever space I can find and just circulate air in the cabin and water back to the lake. Off to Menards for me. Thanks again everyone!
You may be able to save yourself a bit of construction time if you visit your local breakers yard & see if they have any radiators from water cooled motorcycles.
They tend to be a bit more compact than those from cars, I would say a couple like the ones on the CX500 I had about 25 years ago would be ideal.
I have no idea what they are like these days as I haven't had a water cooled bike since but it could be worthwhile checking out.
Vyger5 years ago
This is my my oldest and most viewed instructable, It does exactly what you are asking.

Free air conditioning.
The cold water idea should work OK but I would suggest that rather than a radiator you use coiled copper pipe behind a fan enclosed in a tube the diameter of the fan so the air is drawn through the coil rather than pushed through it; the simplest way would to be to mount the fan in an enclosure in the cabin wall & fit the coiled pipe behind it.
If you were to use 1/4" pipe you could have several layers without it getting too large.
I would agree with canuksgirl an extract fan would also be a good idea, a constant flow through of air would reduce the humidity & create air movement which will add to the cooling effect in the cabin, it would also prevent a positive pressure problem with your cooling fan as the air drawn in would simply replace the air drawn out.
bwrussell5 years ago
What are you trying to accomplish? Does the air temp actually need to be lower or do you just need to perceive it as lower, for comfort only? Simply circulating air will help cool you but won't actually lower the temp in the cabin.

How much lower do you want the temp, or perceived temp? If it's not drastic I imagine that drawing air through your radiator idea combined with canucksgirl's vent you could get decent results.

If you have room for a radiator and pump you could build a heat exchanger. Run a pipe loop around the cabin then down along the bottom of the boat. Put a pump in line, fill it with antifreeze and your set. The antifreeze will pickup heat from the cabin and dump it into the lake. Use a pipe that transfers heat well (not PVC). Add a fan and/or vent to get air moving and you might get slightly better results than just using water albeit in a more complex system.
Of course if it leaks and the EPA finds out they wont be happy. :D
rickharris5 years ago
Freeze some large volume of water - say a large soda bottle.

Blow air over the bottle with a fan.

If you can mix a dilute antifreeze mix and get that to freeze it will freeze colder than pure water.

generally the water will be below the air temperature particularly at depth although you may not wish to trail a radiator deep in the lave!
canucksgirl5 years ago
If the pump idea doesn't work, and the cabin of your boat has an overhead hatch, consider adding a fan to draw out the hot air (and humidity). If the cabin area doesn't have one, you might want to look at installing a vent hatch, as it does make a considerable difference if you can get the air circulating. (It won't be as significant as an air-conditioner, but you'll most certainly notice a difference).