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What is the speed of sublimation?

Harvey Ramer
Harvey Ramer Member Posts: 2,239
in A-C, Heat Pumps & Refrigeration
Say you did a single evac on a refrigeration system and pulled it under 100 microns in 5 minutes. System stays under 150 microns for an hour. Is there any moisture remaining as ice formations inside the piping? Would a micron guage detect sublimation?

Comments

  • hvacfreak2
    hvacfreak2 Member Posts: 500
    It should because the outgassing will increase the pressure . There are a lot of micron gauges on the market so it wouldn't surprise me if one didn't.

    https://accutools.com/blog
    hvacfreak

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

  • ch4man
    ch4man Member Posts: 296
    i'll second the Bluvac used in the blog posted above. itll drive you nuts until you realize its telling the truth. other manufatures are starting to copy (steal) its technology, they should be just as good.

    and inexpensive to boot!
  • hvacfreak2
    hvacfreak2 Member Posts: 500
    The article about pulling vacuum from a drier ( link above ) explains that there is always moisture present.

    I pulled down a small jar with some water for my son's science project years ago. We were able to make ice with the vacuum but we were not even close to 500 microns. The rise was not applicable due to the small size of the vessel however.
    hvacfreak

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
    I have 3 BluVac guages. A spare and a spare for my spare. Because I am a tool nut.

    I asked the above questions in regards to the triple-evac procedure that's being preached to us from every direction. I personally find the triple-evac procedure useful for system service work, but I rarely find it necessary on new installs.
  • ratio
    ratio Member Posts: 3,625
    I sing about it because I've seen how good it works. The biggest eyeopener, mini split evaporator w/ condenser on roof, lineset was left open pointing up. Rain overnight. The N2 flush blew water out of the lineset. An hour & a triple evec later & it was holding below 500 microns.

    I don't always triple evec, especially on the work I do (Note, I was the cleanup man on the above job), but if I have any problems getting it to pull down, I jump straight to a triple.

  • hvacfreak2
    hvacfreak2 Member Posts: 500
    I have one of the very first series Bluevac , I sent it in because it stopped working ( my fault abuse ). He put a new front on it , fixed the unit , and added an update at no cost. He has my business from here on out.

    The only time I triple evac is if the process stalls. Larger systems usually require it , and different manufacturers seem better than others. I like the Bluevac because the 1/10 resolution will let you know if the process has stalled.
    hvacfreak

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

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