Results 1 to 12 of 12
  1. #1
    Join Date
    Jun 2016
    Location
    Sheffield
    Age
    33
    Posts
    5
    Rep Power
    0

    Hague temperatures



    Hi everyone

    Very new to hvac and I am after some advice.

    How do I know what the pressures/gauge temp should be on different refrigerants.

    I know I will likely get shot for this question as there are a lot of variables and has probably been asked loads of times before. It's just driving me insane on how I work this out.

    I am in the UK so would appreciate answers in Celsius

    Thanks

    Tev



  2. #2
    Brian_UK's Avatar
    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    69
    Posts
    10,444
    Rep Power
    50

    Re: Hague temperatures

    If you use a pressure/temperature chart it will help

    The temperature of the refrigerant depends on what it is cooling or heating.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015
    Please support http://the100project.net/Home

  3. #3
    Join Date
    Jun 2016
    Location
    Sheffield
    Age
    33
    Posts
    5
    Rep Power
    0

    Re: Hague temperatures

    Thanks for the reply for example then if I am cooling a cold display counter refrigerant is r404a.

    The ambient temp is 30oC in the kitchen area

    The cold display counter should be running at approx 3 to 4 degrees

    I know how to work out my sub cooling and super heat etc but it's just this what is really baffling me.

  4. #4
    Brian_UK's Avatar
    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    69
    Posts
    10,444
    Rep Power
    50

    Re: Hague temperatures

    If the sub cooling is within expected limits then don't try and change it.

    The superheat reading at the evaporator will only settle out when the unit/system is down at design temperature.

    You have told the kitchen temperature and what you want the cold counter to be but......

    Is the counter in the kitchen?
    Where is the condensing unit?
    What readings have you recorded from the system?
    Was it working before you were asked to look at it?

    We can't see what you have so need a little more info please.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015
    Please support http://the100project.net/Home

  5. #5
    Join Date
    Jun 2016
    Location
    Sheffield
    Age
    33
    Posts
    5
    Rep Power
    0

    Re: Hague temperatures

    The counter is in the kitchen the condenser is located under the unit in a cupboard with louvered doors.

    The gauge temp is -10 and the suction temp out of evap is -7

    40 degree gague temp and 46 line temp out of condenser

    The unit was working last week but had a leak. I found the leak and repaired.

  6. #6
    Brian_UK's Avatar
    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    69
    Posts
    10,444
    Rep Power
    50

    Re: Hague temperatures

    So, the leak was repaired, did you acheive a good vacuum before you recharged it?

    Did you recharge by weight?
    Brian - Newton Abbot, Devon, UK
    Retired March 2015
    Please support http://the100project.net/Home

  7. #7
    Join Date
    Jun 2016
    Location
    Sheffield
    Age
    33
    Posts
    5
    Rep Power
    0

    Re: Hague temperatures

    Quote Originally Posted by Brian_UK View Post
    So, the leak was repaired, did you acheive a good vacuum before you recharged it?

    Did you recharge by weight?
    Vac down to 2 torr, the cold display was changed using reference documents from when it was installed, I believe it was made for the canteen so no data plate is available.

    Apreciate you taking the time to reply, I am really keen to become clued up in all this as I have finally found something I enjoy doing. Much more than repairing lifts 😂

  8. #8
    Join Date
    Apr 2001
    Location
    New Port Richey, Florida - USA
    Age
    72
    Posts
    5,069
    Rep Power
    28

    Re: Hague temperatures

    Quote Originally Posted by tevs View Post
    Hi everyone

    Very new to hvac and I am after some advice.

    How do I know what the pressures/gauge temp should be on different refrigerants.

    Tev
    You might want to check out this thread: http://www.refrigeration-engineer.co...rigeration-101
    Last edited by Gary; 23-06-2016 at 12:46 AM.

  9. #9
    Brian_UK's Avatar
    Brian_UK is online now Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    69
    Posts
    10,444
    Rep Power
    50

    Re: Hague temperatures

    Thank you Gary, I had forgotten about your little thread.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015
    Please support http://the100project.net/Home

  10. #10
    Join Date
    Apr 2001
    Location
    New Port Richey, Florida - USA
    Age
    72
    Posts
    5,069
    Rep Power
    28

    Re: Hague temperatures

    Hopefully, a few people have found it helpful.

  11. #11
    Join Date
    May 2007
    Location
    Auckland
    Age
    67
    Posts
    3,362
    Rep Power
    31

    Re: Hague temperatures

    tevs,
    did you recharge 404a in liquid phase, there is a danfoss app available on line free from danfoss site. " refrigerant slide rule " very handy for every refrigerant .

  12. #12
    Join Date
    Jun 2016
    Location
    Sheffield
    Age
    33
    Posts
    5
    Rep Power
    0

    Re: Hague temperatures

    Thanks everyone much appreciated

Posting Permissions

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