Results 1 to 4 of 4
  1. #1
    Join Date
    Oct 2019
    Posts
    2
    Post Likes

    Confused New to low temp system need advice and explanations

    I just came from a test lab that tested commercial and residental package units and now i have moved to a new company that deals with small commercial food equipment.

    First off the refrigerant type i deal with is 404a and R290 (propane). I test alot of cold tables, cold rails and freezers these are all prototype units.

    My biggest question is i have noticed that if i go by temp and pressure in these systems i show that i am condnesing from a gas to a liquip and then back to a gas before it exits the condenser coil so i end up with superheat and i have yet to be able to get any subcooling out of these types of units. They have no sight glasses. I have asked a few folks but no one has been able to explain this and i think they think i am crazy. Its almost like the condensers used have to much pressure drop but im done trying to make sense of it need an experienced person to explain this.

  2. #2
    Join Date
    Jan 2010
    Posts
    17,359
    Post Likes
    How are you measuring sub cooling ?

  3. #3
    Join Date
    May 2014
    Location
    Bay Area California
    Posts
    24,545
    Post Likes
    Yeah, you need a lot more details for us to have a clue what you are talking about.
    If you were a real tech, you'd solder a relay on that board and call it good to go.

    I do a triple evac with nitro to remove non condensables.

    I use 56% silver on everything except steel.

    Did you really need the " If you were a real tech " ??

  4. #4
    Join Date
    Oct 2019
    Posts
    2
    Post Likes
    Thread Starter
    Liquid line temp minus the saturation temp indicated on the guage set same way i have been doing it for 15 years lol I belive the liquid line reciever is why i cant actually see any subcooling i have measured the incoming side and the outgoing side. The unit doesnt have a sight glass to tell if i actually have liquid to the txv.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •