My old faithful Devilbiss portable air compressor finally died on my after giving 16 or 17 years of faithful service. I found out service parts for it are no longer available, since Devilbiss air power has been adsorbed by DeWalt. My old compressor was 8.8 CFM @ 40PSI and 6.9@90 with a 20 gallon tank. electric 5hp , and oilless. It was a handy compressor to put in the back of my pickup when I would do some small paint work, airbrush, or graphics off location. So I decided to do some compressor shopping, both online and in person at some stores. Everything I have found has a SUBSTANTIALLY lower CFM for a physically similar size compressor, and much lower HP rating. I don't want another big oiled monster like I have stationary in my garage, I just want another small portable oil-less compressor like I had for off site tasks. My big question since I have not been involved with compressor shopping for a long time, is did somehow the way they rate the HP and CFM of a compressor change? Or is it just a case of made in china now is less efficient. It just odd when it seems everything now has a much lower across the board HP and CFM rating. I really don't want to have less capacity then I had. Hopefully some you you can weigh in on this. Attached are pics of my old one and the spec label on it.
Your old comp. is rated in SCFM... That's different than CFM.. do some research , I don't recall what the difference is ... dave
Yes the standards changed after a cl***-action lawsuit a few years back regarding advertised HP and CFM. Funny, my Husky took a dump yesterday, too. Luckily it's under warrantee.
I'm still running the little Sears 1HP compressor I bought in 1965. But my big un died I bought around 1990.
Hi ... Make sure you buy something that big enough to cope with the job....most smaller compressors are no where the rating there suppose to be...if you are painting candys or pearls need a 50-60 plus consistent CMF .. 20Gal tank to get the job done easy...need a constant 2.5-3 bar at the LP GUN regulator....other wise it run out of puff on big panels like Caddy roof...if it drops down to 1.5 bar or below .. you may as well tip your paint on the floor as it will spray dry and look like **** no matter what you do...
Just to change the subject most guys have abandoned the portable air compressor and adopted the cylinder of compressed nitrogen. One cylinder @2000 PSI lasts for months no noise no fuss no electricity.
"most guys" ???? We used nitrogen back in the late 80's as an alternative to the air compressor for small jobs. But it was free...(race car sponsor). I visit car shops on a daily basis and only ran into one shop that was using nitrogen for anything other than filling tires.
I don't mean shops. I mean portable use such as, transport tire service vehicles, race car transporters and the like. The OP said he needs a small portable compressor for paint jobs. If he can run a line to the truck the nitrogen would be ideal.
The OP's compressor was made back when manufacturers of all kinds of consumer grade power tools routinely told big lies about horsepower and any other performance characteristic applicable to the particular tool, such as CFM rating in the case of air compressors. This is the same sort of ******** behind Sears claiming 6 and 7 hp for shop vacs that couldn't make 1.5 legitimate hp without going up in smoke, and everyone and his brother claiming anywhere from 6.5 to 8 hp for lawn mowers that had engines with about 3 legitimate hp. Per the nameplate in the pic, this compressor operates on 120 volts and 15 amps. The amperage is directly indicative of horsepower, so this 5hp motor is actually about 1.7 to 1.8 hp. When legitimate hp numbers are used, 2hp will be the absolute limit of what can be run off of a 20 amp 120 volt circuit. Look at http://www.aircompressorsdirect.com/Images/Campbell-Hausfeld-WL6501-Air-Compressor/i62.html for an example of the overrating. Note the text says 1.7hp but look at the sticker on the compressor itself. Old pic claiming 5hp. As a further example of what a real 5hp motor requires for power, a 5hp 240volt single phase motor will pull about 23 amps at full load. When you cut the voltage in half, it takes twice the amperage to produce the same power. So a 5hp motor running on 120V would pull 45+ amps at full load. All said and done, the oilless compressors available today that are close to 2hp will put out about the same amount of air as your old one. The difference is that the courts nailed a bunch of them to the wall and they have to tell the truth now, although you'll still find enough difference in CFM claims from one brand to another for the same horsepower to make one ***ume some of them are still lying about that spec. All oilless compressors are very inefficient as compared to oil lubed ones of the same size. Always have been, and this is particularly true of the consumer grade models. The fact that about 99% of them are now produced in China doesn't help the efficiency either. There are some US made oilless compressors that are more efficient, made by companies like Gast and Quincy, but they typically cost 4 to 5 times as much as a similar size imported consumer model.
Hi meltmunchr...Thanks for the brief on the REAL hp and cfm..of compressors...seen a lot of poor paint jobs recently and most are blaming their guns...little do they know!!!...we have 240v 30 amp but that still not enough to run a compressor to deliver 40-60 cfm....need 7-10 hp 415v 3 phase to drive a pump...
Volts x amps=watts. 746 watts= 1hp. This discounts motor efficiency. Another rule of thumb for compressors is you can expect approx. 4CFM per HP. Posted using the Full Custom H.A.M.B. App!
FYI Be careful around older portable compressors. Mine blew up a couple of years back. it tried to take a large cupboard off the wall and i am still trying to pick schrapnal out of my legs.
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