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  1. #66
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    Sep 2005
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    Quote Originally Posted by beachtech View Post
    yeah, because 8cfm isn't overkill <G>
    What I was trying to say is: All that fancy stuff does not help much unless one has to stop and watch the pump. If one can find other things to do during the 20-30 min... I do not see it makes much difference.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  2. #67
    Join Date
    Feb 2010
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    In a boiler room
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    7,050
    Vacuum pump CFMs are over rated I use 2 3/8 hoses between pump and core tools.

    I have a JB 3cfm and it pulled down a 30 ton Mitsubishi City Multi system to 1,000 microns in 20 minutes. After a nitro sweep I went and worked on some other stuff and came back an hour later and it was at 80 microns. So yes, 3 cfm is more than enough for anything but the really large stuff.

  3. #68
    Join Date
    Feb 2013
    Location
    Summerville SC
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    I tested the new setup twice today on 2 indoor coil changeouts.1 was 3 ton goodjunk with about 50 foot lineset. pulled down to 250 microns in about 3 minute I guess. I took video of the second system which was a 5 ton (keep in mind 7/8 lineset) with about 20 foot of lineset. it took about a minute and a half to pull to under 500. at first I really didn't trust it but I blanked off my core tools and neither time did it ever go up more than 50 microns.so I can agree with ga-hvac-tech about most of the time u have other stuff to do but I can guarantee every tech has had plenty of times they were wishing evacuation was no such thing because of time. I changed a compressor a few weeks ago and I had to change the combo cap and contactor also so I figured id do that while it was evacuating however I still ended up waiting for 30 minutes after that and cleaning up...that was with a 6cfm pump, 1/4 hoses and cores removed. so no one can really changed my mind after today when I pulled 2 vacuums at maybe 45 minutes including setting up the rig

  4. #69
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    Sep 2005
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    Atlanta GA area
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    Seems anytime the compressor is in the vacuum stream... it takes a L O N G time. Lineset/coil streams take a lot less. The worst is when we change the service valves and the existing pump is still in the stream... one has to evaporate all the refrigerant out of the oil... takes a L L O O O O O N N G G G G G time.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  5. #70
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    Feb 2010
    Location
    In a boiler room
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    Quote Originally Posted by ga-hvac-tech View Post
    Seems anytime the compressor is in the vacuum stream... it takes a L O N G time. Lineset/coil streams take a lot less. The worst is when we change the service valves and the existing pump is still in the stream... one has to evaporate all the refrigerant out of the oil... takes a L L O O O O O N N G G G G G time.
    Yes, and what is nice about the Bluvac, it is easy to see that happening. It looks completely different that a leak.

  6. #71
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    Feb 2013
    Location
    Summerville SC
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    117
    Quote Originally Posted by chuckcrj View Post
    Yes, and what is nice about the Bluvac, it is easy to see that happening. It looks completely different that a leak.
    now when you say that what exactly do you mean?i have never had the grace of using a bluvac from plan on getting one from the recommendations on this thread

  7. #72
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    Feb 2010
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    Quote Originally Posted by SCtech33 View Post
    now when you say that what exactly do you mean?i have never had the grace of using a bluvac from plan on getting one from the recommendations on this thread
    If you get the Bluvac with the leak rate indicator, it will tell you how fast the micron level is rising or falling in tenths of a micron per second. When it is falling you get a negative number, when rising you will get a positive number.

    When pulling a vacuum with a leak, you get a steady fall until the point where the vac pump is not pulling any faster than the leak is entering. Valve off pump and micron level will steadily rise.

    When pulling a vac on a system with a lot of refer still trapped in the oil, the micron level will start falling but usually when it gets below 2,000 it starts jumping. The overall trend will be downward, but every few seconds (or faster depending on the amount of refer left) the leak rate indicator will go momentarily positive indicating another bubble of refer popped out of the oil.

    I wish they named it something like "change rate" or similar instead of leak rate.

  8. #73
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    Feb 2013
    Location
    Summerville SC
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    117
    ok I get what your saying.ive seen that happen on my old supco vg64...gets around 1500-2000 starts going bananas and after a few minutes (if not after a nitrogen sweep) it pulls down like normal. but yea ive seen where they have that feature just didn't know if there was a trick to reading it. but hopefully Ill have mine soon!

  9. #74
    Join Date
    Feb 2008
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    Waffleville
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    10,339
    Quote Originally Posted by ga-hvac-tech View Post
    What I was trying to say is: All that fancy stuff does not help much unless one has to stop and watch the pump. If one can find other things to do during the 20-30 min... I do not see it makes much difference.
    all that fancy stuff lol

    if i where pulling down virgin air handlers and fresh linesets, and doing a trim out while waiting on a pump. yeah. but since all i work with is old beat up junk that has to be brought back from 40 hells, i love my fancy vacuum setup that i put together
    If Guns Kill People, Do Pencils Misspell Words?

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  10. #75
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    Sep 2005
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    Atlanta GA area
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    Quote Originally Posted by beachtech View Post
    all that fancy stuff lol

    if i where pulling down virgin air handlers and fresh linesets, and doing a trim out while waiting on a pump. yeah. but since all i work with is old beat up junk that has to be brought back from 40 hells, i love my fancy vacuum setup that i put together
    I see where you are coming from... you are in a different market than I am. If I had to watch a vacuum pump (paint dry) regularly, I would have a vacuum tree also (I actually do own one, just do not bother to get it out and use it). As it is... I probably do less than 20 repairs a year where I have to resort to cleaning up the jobsite while the 20-30 min passes to pull a good vacuum.

    I do LOTS of resi replacements... the goal is to get the coil and condenser in and the lineset buttoned up ASAP... then do other things while the vacuum is pulling down (usually go for 250, through a manifold without core tools). I can get that in 25-30 minutes on an average system, 20 min if the lineset is clean. (You still think that Appion vacuum pump is not a good investment... ). OH, BTW: The rise is usually less than 100 from 250... not a bad vacuum on a resi system.
    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  11. #76
    Quote Originally Posted by ga-hvac-tech View Post
    I see where you are coming from... you are in a different market than I am. If I had to watch a vacuum pump (paint dry) regularly, I would have a vacuum tree also (I actually do own one, just do not bother to get it out and use it). As it is... I probably do less than 20 repairs a year where I have to resort to cleaning up the jobsite while the 20-30 min passes to pull a good vacuum.

    I do LOTS of resi replacements... the goal is to get the coil and condenser in and the lineset buttoned up ASAP... then do other things while the vacuum is pulling down (usually go for 250, through a manifold without core tools). I can get that in 25-30 minutes on an average system, 20 min if the lineset is clean. (You still think that Appion vacuum pump is not a good investment... ). OH, BTW: The rise is usually less than 100 from 250... not a bad vacuum on a resi system.
    As much as I fancy my Appion hoses and CRTs, I can't buy the Tez vacuum pump.

    It is too noisy. FWIW, some of my local HVAC acquaintances Uesd the Tez vacuum pump on an early Sunday morning install. The noise was so bad they got a warning from the cops for "Disturbing The Peace".


    Another thing I don't like is the dual piston system for producing vacuum: Plastic pistons? I don't know what kind of break down ratio they have, but it has got to be more than a rotary vane pump.

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