instead of plugging it into a wall socket you plug it into an air hose. You need a good amount of air (about 5-7 scfm) and you should have a drier for the air compressor. It uses a Venturi to pull a vacuum. We use air operated vacuum sources in a variety of industrial applications, but they make them specifically for AC work too, I did one coworkers car two years ago when he replaced his compressor dryer and orifice tube. Did two last summer and about to do another, never had an issue with them they pull down to 28".Originally Posted by toof
Jeff
