Results 1 to 4 of 4
  1. #1

    Purposes of mainfold gauges

    Hi All,

    I am still in school for HVAC/R and we havent gone over mainfold gauges much. This is a very basic question that I would like some clarification on. It seems like there are only a few reasons to hook up the gauges:

    1. To add/remove refrigerant from the system
    2. Check superheat for evaporator performance
    3. Check subcooling for condenser performance

    What are some other reasons you would hook up gauges for? I know that each refrigerant has specific properties. boiling temp, condensing temp etc.. but, am not sure why I hear my boss at work say he hooked up the gauges to check the system when I know he didnt check the superheat or subcooling. What could he possibly be reading gauges and referencing the p/t chart for? Is there some simple calculation that I am missing? Thanks in advance for the help and forgivness of the simple question.

  2. #2
    Join Date
    Jun 2006
    Location
    New Jersey
    Posts
    4,336
    Quote Originally Posted by nicklawni View Post
    Hi All,

    I am still in school for HVAC/R and we havent gone over mainfold gauges much. This is a very basic question that I would like some clarification on. It seems like there are only a few reasons to hook up the gauges:

    1. To add/remove refrigerant from the system
    2. Check superheat for evaporator performance
    3. Check subcooling for condenser performance

    What are some other reasons you would hook up gauges for? I know that each refrigerant has specific properties. boiling temp, condensing temp etc.. but, am not sure why I hear my boss at work say he hooked up the gauges to check the system when I know he didnt check the superheat or subcooling. What could he possibly be reading gauges and referencing the p/t chart for? Is there some simple calculation that I am missing? Thanks in advance for the help and forgivness of the simple question.
    You are on the right track and your boss isn't.

    It pointless to hook up your gauges with out looking at temperatures also.

  3. #3
    Join Date
    Sep 2007
    Location
    New York State
    Posts
    20
    You are right. The gauges should be used to check the sub cooling and super heat. Old school techs think they can tell the system is operating from just reading pressures.

  4. #4
    Join Date
    Oct 2008
    Location
    NH
    Posts
    23

    know what you mean

    Im recently out of school and have been riding with alot of different techs, most of wich when doing preventative maintenance on air conditioning will install there gauges and say looks good. Im like you and ask how do you know. What ive realized is when these guys have 20 units to look at and change filters, belts, pulleys, etc. There not taking the time to properly analize a system. what there basically looking at is that the low side pressure isnt low enough they need to worry about the evap coil freezing and that the high side pressure is in the ball park of what they expect to see givin the feel of the ambient temp (meaning no measurment just feels about 80)

    do i think its right no but who looks better and keeps the boss happy? the Guy who can get 20 units done in a day but has a call back every now and then or the guy who does everything by the book but only gets a few units done. I dont know yet Im still figuring it out.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event