Title
Build Your Own Silent Air Compressor

Author
Inservible

Published
Tuesday, October 21, 2003

This is an advanced project that requires knowledge of welding. If you don't know anything about welding it is not recommended you attempt this project!

1) Ok, let's start by saying that here in Argentina compressors cost about 450 Argentinian Pesos -- approximately US$150. It is for a 1HP compressor, and for about 25 Lts (845oz), this is not so expensive since it soon would be paid off. The problem is they're too noisy to use them at home, and they are not very good. That is to say, a very poor quality. Besides, a moisture filter and quick connectors have to added, etc. Due to this, I had to resort to making my own compressor. Below, you'll see it's not too difficult to do it and not so expensive.



2) This is my baby. It's quite complete, except for the moisture filter and the presostat missing. As you can see, it consists of a refrigerator motocompressor (6) and a 13.5 Lts. (456.5 Oz) tank, which is a freon gas carafe used by people who repair refrigerators and air conditioning.



3) A base (2) made out of a 3 x 12.5 mm(0.11x1/2” iron sheet and a ½” square pipe, were both welded together, and in turn, both were welded to the tanks.



4) Then, a U-folded #16 steel plate was welded to the tank. This plate would be the base for the refrigerator's motocompressor (6).



5) Up to now, we have the tank and the base for our motocompressor (6), that is to say, we have finished the body and the base. Now what follows is the air entrance, which is made by drilling a hole on the tank and welding a ¼” gas nut to a one-way valve (1). Such valve may be of two different types. They can be placed inside or outside the tank, but in both cases it works the same way. There, I have put an external valve, because I couldn't find the other one, anyway, it's the same.



6) Once the air entrance was drilled, the outlet is what follows. Here we can use the carafe outlet, but the problem is -- as you can see on the picture -- that the carafe's outlet thread is ¼”flare –a thread used only in air conditioning-, so we should make a transformation to a ¼” gas one. To do this, we use transformations sold only in air conditioning stores, then we put a ¼” gas cross, screwing up a hose connector; a pressure gage -- which measures the pressure in the tank -- and a safety valve(5), or a presostat, if we don't want to turn the compressor on and off once it reached the required pressure.



7) Once the outlet is finished, we should start connecting the hoses which go from the hose connector in the outlet, at the pressure regulator entrance (3). This one generally has the moisture filter and a pressure gage to be able to see at which pressure it has been regulated. These connections are made by means of high pressure hoses, as can be seen on the picture.



8) Next to the regulator, it can be seen the switch I have made, which has a neon indicator. The box was made out of styrene.

Hope this has been useful for you, the pressure at which I make it work is from 0 to 6 Bar (0 to 87 psi). Whatever you need, you know where to find me!