getting the right size vacuum pump

[chrashley]

What would be a good cfm of vacuum pump to have. I do only resi work. What are the best brands and why? Thanks!!

[weber]

I recommend the YJ 1.5, because its the best setup I have ever used.

[beachtech]

we use 5 cfm and 6 cfm pumps

[weber]

we use 5 cfm and 6 cfm pumps

Well, that explains alot

[BigJon3475]

I have a 3 cfm dual stage I think it's a bit to big for the systems I have. I would try and get the smallest dual stage possible.

[beachtech]

Well, that explains alot

i use what they give me

http://robinair.com/product-new/deta...=1061&catid=11

[mario_m]

This thread may help you:
http://www.hvac-talk.com/vbb/showthread.php?t=159232

Go to the JB website (jbind.com). There is plenty of literature available on selecting a vacuum pump that is right for you. Try to find a distributor of JB, they may let you test out some vacuum pumps. I'm currently testing a 7 cfm and a 3 cfm.

The most simple way to sum things up is that cfm doesn't mean a whole lot. Once the system reaches a vacuum, which is usually less than a couple minutes on small systems, a 1.5 cfm to a 10 cfm work pretty much the same.

[beenthere]

They work the same. But the larger one will still be drawing quicker. The primary is still bigger.
If you draw too quick, you could form ice crystals.

[bdivell]

I personally use a 6 cfm Yellow Jacket and have a never had a problem with it very easy to use and quick

[beenthere]

I use a 6 also.
Have seen a lot of guys use 7's.

No need for a large vac, for small resi stuff though.

[BigJon3475]

All I work pon is small residential sized systems. I have to play with the ballast within a few minutes to keep it around the 3000-5000 microns.....I'd rather it take a little longer to make sure it's not forming crystals instead of boiling off.

[chrashley]

So a 5 or 6 cfm YJ, robinair, or JB pump would be the best way to go. And always dual stage...right?

[beenthere]

If your not going to work on anything bigger the 20 ton, a 3 CFM works good.

But a 5 or 6 will do also.