Build your own Air Conditioner

[Steve]

Has anyone ever built their own with old automotive parts.



If you took an old engine such as a lawnmower engine you could run an automotive compressor off of it. Chevy Suburbans have a second expander in the rear and would have plenty of line to use in a bus. You could also have it drive an automotive alternator to run your inverter. Just an idea I've been thinking about

[lapeer20m]

i tried using a lawn mower engine to run an automotive alternator for battery charging. It worked ok, but was really noisy. It would take a good size engine to run an a/c compresor, i would bet at least 5 hp if not more. I dont' know much about cooling systems, but i do know that freon or the modern equivilant is not cheap. Window a/c units are super cheap and easy to find in the newspaper want adds. I would think a couple of these would be a better starting place than trying to assemble an auto style system run off of a gasoline motor.



one quick note. Auto a/c compressors are some of the most impressive air compressors i've ever seen! The freon had all leaked out of the a/c system on one of my old cars, so i converted the compressor to compress air and fill an auxillary tank. With the engine at 4000 rpm's, that little compressor would easily out-perform the 220volt 7hp commercial air compressor i have in my barn.

[Steve]

I just hate how inefficient the window units are, and the fact that they run on electricity.

[andybus9]

hey lapeer20m, the guy with the hot tub ford ward bus. Can you tell me how you converted the cars ac compressor to make air ? I want to install a aircompressor on my bus. What are the specs on yours?

Also Has anyone thought of using a window unit with a new box that could be fit on top? I know that the RV roof Top airconditoners are 110 volts and are far more expensive than window ones? I wonder if these could handle the vibration?

Andy B bus#9
minnesota

[Steve]

Originally Posted by andybus9

Also Has anyone thought of using a window unit with a new box that could be fit on top? I know that the RV roof Top airconditoners are 110 volts and are far more expensive than window ones? I wonder if these could handle the vibration?

I have some pictures of this, I'll post them later.

[lapeer20m]

Using the AC compressor as an air compressor was really really easy. I do have to admit that the compressor didnt' last more than a year and a half after the conversion. Perhaps some pre-compressor lubrication would make it last longer. I think the freon is used as a lubricant in the stock system. The A/c on my car quit working, but the compressor was still good.

All i did was cut the two lines going in/out of the compressor. The inlet needs an air filter. The outlet ideally should go to a tank and a pressure switch. My car didn't have room for the tank, so i just put a quick disconnect for an air hose on my compresssor.

There are two wires that go to the compressor to make it turn on/off. Hook these two wires to power and the clutch engages. It doesn't matter which one is ground and which one is hot, it's just an electromagnet. A switch should be connected to one of the wires so you can turn the compressor on only when you need it. One of the wires also needs to be connected to a water pressure switch. These can be found at Home Depot for about 20 bucks. Mine took a slight modification to run 120 psi, but all it required was a few washers.

If you leave the compressor clutch engaged when you park, beware of dead battery !

Any questions??

[busone]

The reason that the compressor died was it needed oil. In an A/C system part of the refrigerant charge is oil. I am a member of a few groups that are about building WVO burners for heating and many of the people use old refrigerator compressors. One guy came up with a way to introduce a small amount of oil to the compressor to keep it from drying up. I will look for the diagram of how to do it. If you could find an ac system from a 1995 or newer car it would be setup to run on the new refrigerant, R134a. You can buy it at wally world at a reasonable price. I have thought about doing the same thing when I get my bus. I would use two separate units. One will be driven off the bus engine and the other off a separate engine. I have also thought about using several window A/C units but I am not sure how well they would hold up to the vibration. I also worry that the condensation would splòÂ*¯
out the front grill when I hit a bump.

[Ryan Grimm]

I may be mistaken, but Home Power magazine has done articles and tips on low-power-consumption A/C units that use a low-voltage compressor, or similar for fridges. Some are belt-driven pumps, so they might be driven by a small (5+HP) aux engine.

Look in their archives for info. Basically they talk about assembling your own reefer units from components you can purchase from a supplier(s).