Compressor Air Filter Question

[Debo]

Hi guys,

I'm in the process of replacing my air bath air cleaner with a Donaldson Eco filter. I've got that part all squared away.

My engine-mounted air compressor (Truflo 700) also gets its air from the air bath housing, so I'm going to get a separate air filter intake/silencer for it once the air bath is removed. The Truflo 700 is a 15.5 CFM compressor. This may seem like a stupid question, but if I get a filter intake housing rated for 35 CFM, it shouldn't restrict anything, right? There's no rule about how much input CFM is related to output CFM or anything like that, is there?

I think it should work fine, but I just don't want there to be some factor I'm not considering. Thanks in advance.

[Debo]

I think I answered my own question. I found this after a little vigorous Google searching:

"When a compressor pumps one "CFM" (cubic foot per minute), that means the intake port inhales one cubic foot of "free air" (air at atmospheric pressure, which is 0 psig) per minute. (Note: A CFM does not mean in any sense the compressed volume.) So the unit really measures the mass of air flowing per minute, not volume per minute, since a cubic foot of free air is a unit of mass. Some people labor under a stubborn misundertanding that these units refer to the flow of compressed volume (as opposed to free air volume), but this is flatly wrong. The confusion arises because the term "cubic foot" sounds like a measure of volume, when in fact this term in this context is an abbreviation for "the mass of a cubic foot of atmospheric air", which is a measure of mass."

I'm inclined to believe this, because everything you read on the internet is true, right? 

I'll go with this answer unless I hear differently from anyone. Hopefully me asking the question will be helpful to someone down the road.

[brmax]

Debo, i had my hand up
You meant your oil bath air filter housing right? or maybe not
Any way some of the newer housing have inlets for the air compressor connection, and many Vehicle MFG's have tech bulletin updates on other intake pipe connections having learned about a reverse pulses in air flow, I have changed many in accordance to these.
Im understanding free air is with out producing vacuum on inlet this almost has to be twice the outlet?
Good Day There

[bevans6]

FWIW and not saying this is the best way to go, I got me one of those K&N oiled air filters that you see on Hot Rods for valve cover vent filters, and motorcycle air filters.  3" round, and a clamp on base suitable in size to the intake tube.  Just clamped it on and didn't think about it again.  I had the exact same ditch the oil-bath stock setup in favor of the Eco filter deal, and lost the compressor feed.

Brian

[TomC]

There are air filters made for the air compressor. I have one on my bus and just replace it every other year. It is the cutest little air filter you've ever seen. Good Luck, TomC

[Oonrahnjay]

FWIW and not saying this is the best way to go, I got me one of those K&N oiled air filters that you see on Hot Rods for valve cover vent filters, and motorcycle air filters.  3" round, and a clamp on base suitable in size to the intake tube.  Just clamped it on and didn't think about it again.  I had the exact same ditch the oil-bath stock setup in favor of the Eco filter deal, and lost the compressor feed.

Brian

    You'll see a lot of disagreement on this, but -- in my mind -- one of those things is about as useful as having an old toilet paper roller taped onto the end of the intake tube.  I'm convinced that more dirt, dust, grit, and small kittens gets through those things than originally got to the front of it in the first place.  I'll always go with a good quality paper filter. 

[Debo]

Good morning all. Thanks for the replies. It's always really helpful for me to run ideas by you guys. It looks like some of you have had some of the same challenges with switching over. Just to clarify a few things...

I did mean I'm replacing the "oil bath" filter - not air bath. As far as the compressor filter, I found a Solberg steel canister air filter housing with included little paper air filter on E**y for $30. It's got a 1" threaded outlet that I can plumb onto the 1" intake pipe of the compressor after I separate it from the oil bath. The little filter is replaceable, and costs about $6 at NAPA. These little Solberg filter housings are made specifically for air compressor intakes, so I feel pretty good about that. My original question just dealt with making sure I got the right size for my application. For the record, I went with the FS14100. I'm not saying this is the right solution for everybody, but it looks like it should work for me. Cheers.

[luvrbus]

If you have a 1 in plug on the air horn on top of the blower (N/A engine) you can feed a compressor from there all Eagle buses with the 8v71 are plumbed that way