Results 1 to 5 of 5
  1. #1

    Confused pressure questions

    i have recently started working as a helper in hvac. my supervisor cannot explain to me questions i have. whether or not he actually knows the answer.
    with that said i have a million and one questions.....
    what should the pressure differential be between low & high lines to ensure optimum efficiency? and does that change when a hp reverses?
    these guys (my employers) build custom equip. and act like every question i have is a threat to some secret they dont want to share.

    tired of being in the dark, thanks

  2. #2
    Join Date
    Jan 2004
    There is no one set differencial between the 2.
    Generally you want the head 100PSI above the vapor pressure in cooling. But some new higher SEER equipment runs less then that. Compression ratio varies with each manufacturers design.

    HP's run different yet.

    Get your post count up. At 15 you can apply for pro membership. Where things such as this are allowed to be discussed in detail.
    Contractor locator map


    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Apr 2008
    Rochelle Il / Chicago
    I understand your frustrations, How ever. 1st rule is to show only respect for your employer. Have you had any schooling? If so then you would understand how the questions might stump the guys that have been building this industry. The pressure dif as you asked will be as reflected from total load and ambient. Since the sun don't show every day psi's dif will fluctuate.

    Remember, Your boss gave you the job, show some respect.

  4. #4
    get you a P.T. chart and learn how temperature effects pressures thats a good start.each refrigerant will have a different pressure temp relationship

  5. #5
    Join Date
    May 2008
    Spfld, IL
    your question reminded me of some of the off the wall technical questions I would ask when I started. asking questions is good. but with experience you will learn to ask the right questions.

    welcome to the trade.

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