Vacuum pump for HVAC

[Stretch]

NO. You got the wrong kind of vacuum pump for airconditioning work. It is not even in the ball park for that purpose.

Stretch

[Carolina Breeze HVAC]

No, its not. For R410a, its not even close, and for 22, its not even marginal. What brand of micron gauge did you buy?

[TURTLE]

This is Turtle.

User , 25'' would be just maybe fair on a 100ºF+ day and very dry day but 25" is just kind of on the short side to saying you pulled a good vacuum. you really need to get you a 29" vacuum unit to do a good job.

TURTLE

[User Example]

I have an oiless vacuum pump. It will pull 25" Hg. Is that enough for air conditioner line evacuation or do I need more sucking power?

[Red Cloud®]

You suck enough all by your lonesome!

rusty redcloud

[The Reverend Natural Light]

I use a compressor from an old refrigerator for automotive AC work. It'll pull 30" vacuum with no problem.

[User Example]

is

Thanks. I might be able to get another vacuum pump and put them in series. I can get >29" easily that way.

[TURTLE]

This is Turtle.

If a Vacuum punp can pull a 25" vacuum it will only pull a 25" vacuum and series them is right next to nothing but yoiu may try it. You really need a Vacuum pump made to try to gert to the 29'' magic number.

TURTLE

[Carolina Breeze HVAC]

LOL No, it wont.. What brand of Micron gauge are you reading this with, cause if its with your manifold, its wrong.

>

[The Reverend Natural Light]

I only worked on automotive AC and use the same Snap-On R134A manifold set that any other mechanic uses. The HVAC techs I've had work on my home AC unit use identical manifold sets, but with different pressure ranges. Is there a more appropriate gauge for that purpose?

[Stretch]

Why not get a good vacuum pump fesigned for the job instead of doing slack work with the wrong machine. $30,000 fine and 5 years in prison if one of your customers turns you in for venting. Triple purge and evacuate USED to be legal, but even then you were supposed to use a DEEP vacuum pump. Your manifold gauge cannot measure a deep vacuum, they are not accurate and the resolution is too low. Get good tools and instruments. Of course if you are doing the work for yourself, maybe you deserve the results.

Stretch

[Richard J Kinch]

If you vacuum-flush-repeat with refrigerant a few times it will be. Just don't tell the EPA.

[Stormin Mormon]

No, that's not deep enough vacuum.

Needs to go a lot lower than that, to be effective for HVAC work.

[Richard J Kinch]

Pull the best vacuum you can, repressurize with refrigerant gas. Repeat.

Sort of like rinsing a bottle you can't quite empty.

[User Example]

Considering 30" is perfect vacuum on earth, I doubt you can go a lot lower than that.

[User Example]

How do you do that? I'm interested.

[TURTLE]

This is Turtle.

If You get close to the 29 inches and under 400 Microns. It will mean a clean system for a long running life.

TURTLE

[User Example]

Gotcha. Actually, looking at my A/C manual, that's the way it says to install it. It just says run the freon out from the high to low side.

[User Example]

I think I am just going to call A/C guy. This is too much trouble.

[Stormin Mormon]

Uhm, where to begin.

While your gage may point to 30, a perfect vacuum is the same number as the barometric pressure for the day. Ever had a barometric pressure of 30? I didn't think so.