Compressor Flow Issues-1

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New question: How much air do I need to pump in/out of compressor room?

We are setting up a 5x6x10 ft room for our 5hp/60gallon tank compressor. What is the proper size of fan/ventilation we need to keep the room cool and intake air cool if the air intake is in the room? What if the air intake is outside the room? If it is better to have the air intake outside the room, the room of the unit is 25ft and we have no access to it, how do we change the air filter? Is there another type of filter we could use? Thanks for your help.

My response to how much air Hello Peter. Welcome, and thanks for writing in. How big is the intake port on your air compressor? That's the minimum size needed to allow air to enter the room, and I'd make it larger if there was the space to do so. No point in restricting air flow if it can be avoided.Much of what you are asking about is already covered on this site. Please see the links listed on the sitemap and troubleshooting pages relating to compressor location.

New question: How to convert bar to cfm?

i am planning to install a new shop ..... where i have several machines ... all have given their cfm values and 6 bar press requirements ....... how to convert bar to cfm .... or how to calculate cfm?

My response to convert bar to cfm: You convert Bar to PSI, not to CFM, by multiplying the numbers of Bar by 14.7. Therefore, 10 Bar equals approximately 147 PSI. Both Bar and PSI are units of pressure, not flow.

CFM is the measure of flow. BAR is the measure of pressure. When you say how do you calculate CFM, in what are you calculating it, Ashwin?

New question: Can't air up my motorhome tires with my compressors?

I have 2 (nominally) 125 PSI air compressors. One is a 5 gallon, 2 hot dog variety and the other is an upright 12 gallon style. Both work great at running my air tools and airing up car/motorcycle/ATV tires. But neither one will air up my motorhome (bus) tires that take 100 PSI for the rears and 115 PSI for the fronts. What's the problem?

My response to can't air up my motorhome tires Since you've tried it with both compressors Daniel, and that means two air lines, then either the tire gauge adapter you used for both air lines isn't working, or the tire valve isn't working.

If you take the tire fill valve off the line, and put on a blow gun, and depress the trigger, does air come out the blow gun? If so, then you have air at the tire valve, so the problem is either the tire fill adapter or the valve on the tire itself.

If you don't have air coming out of the air line when you trigger your blow gun, then, what is your regulator setting on the discharge line from the tank? If the regulator setting is below the pressure already in the tires, air will not flow into but out of the tire.

New question: If I fire a nail from my coil gun it drops the line pressure 20-25 psi...?by Jerry

My new compressor is 3.5hp 6 gal double stacked tanks with a rating of 5.3 cfm @ 90 psi. I have a coil roofing nailer and 1/2" impact driver. If I fire a nail from my coil gun it drops the line pressure 20-25 psi and my impact driver will only run effectively for 2-3 seconds.

The tank pressure fills to 125 psi and very slowly refills line pressure, 5-7 seconds after a nail fired. Does this sound like a regulator issue? I spent quite a bit of money to upgrade from a smaller compressor that worked fine for almost ten years with these tools.

My response to the line pressure drops to 20-25 psi...? Jerry, look at how big and how long your air line is first. See PRESSURE DROP linked from the site map page for more info on how that affects air flow.

It could be some sort of line blockage from the tank. What is the pressure setting on your regulator? More likely though, it sounds as though the regulator might be the culprit.

Before replacing though, ensure that the connector fits the coupler, OK? If they are mismatched, that could impede air flow even though the regulator is OK and the tank is full. Something is, for sure, slowing the transfer of air from the tank to the air line. What you are seeing is not normal air flow.

New question: Compressor air output at different pressures?

Why do compressors have higher flow rates (SCFM) at lower pressures? There is more air inside the tank at 90psi than at 40psi. Opening a line of given dia. would allow more air to escape at the higher pressure, yet all suplliers list higher flows at lower pressures. This confuses me.

My response to air output at different pressures? You are correct! A container of compressed air will have air flow faster from it if the tank has 100 PSI in it rather than 50 PSI.

The issue for the compressor manufacturer is not the flow from the tank to the tool necessarily, but flow from the pump to the tank, and, at higher pressures, the pump outputs less flow to the tank than it can at lower pressures. See the page Calculating CFM for more info.