Vacuum Pumps

StonePorkchop

Hi all,

Just starting to go out in the field without an escort, and had some questions about which vacuum pump to buy. I work on residential and light commercial. So here are my three questions.

1.) What size pump should I be looking at (CFM's) ?

2.) Rotary vane style pumps Yay or Nay?

3.) Recommended pumps? I obviously want to get the lowest price possible, but I don't want to waste money on a "great deal" and hate the pump.

I thank you all in advance for your input.

ChrisJ

I use a Robinair 15600. Its a 2 stage 6 CFM pump that can pull a 15 micron vacuum (allegedly).

I would recommend similar or better. If I had the money I probably would've bought a decent Yellowjacket one, something like model 93560. You'll find the Robinair 15600 is much cheaper though and it is a pretty good pump.

Don't forget a good quality micron gauge! You're blind if you try using your low side manifold gauge, it's useless. I use a Yellowjacket 69086 micron gauge but there are plenty of options. The most important thing is to connect it as close to the unit you're vacuuming as possible, and try to keep it oriented in a way that will keep oil out of the sensor. Also, cleaning the sensor may be necessary from time to time depending on how you use it. Once oil gets in the sensor it needs to be cleaned.

StonePorkchop

I was actually looking at the Robinair 15500

ChrisJ

StonePorkchop said:

I was actually looking at the Robinair 15500

It'll work for now, but may not last if you use it a lot.
Also remember, many guys leave these pumps running nonstop for hours and hours.

If you need something to get the job done for now, it'll work. Just remember to keep the oil clean.

StonePorkchop

I won't be using it a whole lot. I'm on the maintenance end, not install. So I would only be using it for coil replacements. Generally I've seen guys able to pull a 500 micron vac in an hour or less (not specifically with the 15500).

ChrisJ

StonePorkchop said:

I won't be using it a whole lot. I'm on the maintenance end, not install. So I would only be using it for coil replacements. Generally I've seen guys able to pull a 500 micron vac in an hour or less (not specifically with the 15500).

Do you have a way to recover refrigerant if need be?

StonePorkchop

Yes, I have a recovery machine.

EBEBRATT-Ed

You don't need more than 3 cfm. The restriction to fast evacuation is the hoses, not the pump. Putting a big pump on with small hoses doesn't do anything as far as evac. performance

ChrisJ

EBEBRATT-Ed said:

You don't need more than 3 cfm. The restriction to fast evacuation is the hoses, not the pump. Putting a big pump on with small hoses doesn't do anything as far as evac. performance

I have a YJ Brute II manifold with a 3/8" vacuum line.

I didn't think of that when I responded, good point @EBEBRATT-Ed

ratio

I'll second (third?) the hose sizes comment. With a four valve manifold & a 3/8" vacuume hose I pulled a refrigerated warehouse system (~145 lbs of 407a IIRC) down to under 500 microns in just a few hours. I was astonished.

That was with a J B vac, brand new Imperial manifold, and a Yellow Jacket vacuume gauge

Techman

You are just starting to go out on your own? And you supply reclaim drums,reclaim pump,vac pump,micron gauge,evac manifold? I like you! Come work for me!!! What else do you supply?LOL!

StonePorkchop

Sorry. Let me clarify. The company I work for, is finally sending me out on my own. I have to buy my own gauges and vacuum pump. They provide the rest. Now, back to the topic.

ktully1973

I am considering buying a vacuum pump and appreciate the post. What pump did you end up buying?

StonePorkchop

The Robinair 15800 8cfm 2 stage.

rwhtg

look up HVAC school on podcast app or there is an "Evacuation 101" podcast...its gold

newagedawn

ya, i have a harbor frieght 3 cfm pump and i do residentail, light commercial and refrigeration and that little pump has been running strong for 4 yrs now, altho i change the oil regular, after 4 to 6 vacuum pulls, that pump is the best and price wise try and beat it

ChrisJ

newagedawn said:

ya, i have a harbor frieght 3 cfm pump and i do residentail, light commercial and refrigeration and that little pump has been running strong for 4 yrs now, altho i change the oil regular, after 4 to 6 vacuum pulls, that pump is the best and price wise try and beat it

Most if not all manufacturers say to change the oil after every pull.
I personally do, but I don't do a lot of them.

A lot of guys seem to only change it when and if the pump falls over in the van and it all leaks out.


That Harbor Freight pump can pull down to 250 microns in a reasonable amount of time on the typical residential system?

jumper

Do you guys reclaim your oil?