Results 1 to 12 of 12
  1. #1
    Join Date
    Oct 2009
    Location
    UK
    Posts
    8
    Rep Power
    0

    Ideal gas pressures



    HI,

    Can somebody please let me know the ideal refrigerant pressures High and Low for R407c, R410a, R22, R134a......

    Thanks



  2. #2
    Brian_UK's Avatar
    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    76
    Posts
    11,025
    Rep Power
    60

    Re: Ideal gas pressures

    Depends what they are being used for.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  3. #3
    Join Date
    Oct 2009
    Location
    UK
    Posts
    8
    Rep Power
    0

    Re: Ideal gas pressures

    non inverter AC systems and fridges

  4. #4
    Join Date
    Aug 2006
    Location
    england
    Age
    50
    Posts
    3,856
    Rep Power
    46

    Re: Ideal gas pressures

    If you look at your gauges or better still get one of those slide rule thingies there will be a chart of pressures and temperatures. Change the temperature and the pressure will change also. Have a look at this and get a feel for how different evaporating or condensing temperatures will alter the presssures.
    So a room ac system cooling a room at 30C will have a different suction pressure to one running in a room at 18C.

    Your question is impossible to answer accurately without specific system operating conditions.

    I may well be wrong in guessing your motives for asking but there is no chart of correct pressure to see if a system is working ok. Its not that simple.

  5. #5
    Join Date
    Jul 2008
    Location
    London
    Posts
    848
    Rep Power
    17

    Re: Ideal gas pressures

    ONE......HUNDRED......AND.........EIGHTY!!!!!!!!!!!!!!!

    opps sorry wrong forum..my bad

  6. #6
    Join Date
    May 2006
    Location
    India
    Age
    74
    Posts
    399
    Rep Power
    18

    Re: Ideal gas pressures

    Varies with design conditions . However a compression ratio below 10 should be safe or ideal pressure.

  7. #7
    Join Date
    Oct 2009
    Location
    UK
    Posts
    8
    Rep Power
    0

    Re: Ideal gas pressures

    Ok Thanks, I wasnt meaning an exact pressure and also I was meaning a fridge operating at 2 or 3 degrees, and an AC system controlling at 21 degrees for example.

  8. #8
    Brian_UK's Avatar
    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    76
    Posts
    11,025
    Rep Power
    60

    Re: Ideal gas pressures

    As Monkey said above, use your PT tables to find the expected working pressures/temperatures.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  9. #9
    Join Date
    Jan 2008
    Location
    India
    Age
    70
    Posts
    171
    Rep Power
    17

    Re: Ideal gas pressures

    For reading the pressure temperature chart you need the suction pressure and discharge pressure.
    And the pressure depends on ambient prevailing also.

  10. #10
    Join Date
    Feb 2008
    Location
    adelaide sth.oz
    Posts
    1,015
    Rep Power
    19

    Re: Ideal gas pressures

    good onya multi your right,one woulds think that everything is related at different pressures to achieve evaporating temperature,
    triple top for me
    cheers
    mmm to beer or not to beer...........lets drink breakfast

  11. #11
    Join Date
    Oct 2004
    Location
    uk
    Age
    56
    Posts
    193
    Rep Power
    20

    Re: Gas pressures

    hi colsy welcome to fridges. for the reqired temp, use an evaporating temp/pressure about 10c lower than the temperature required. its a useful rule of thumb. regardless of the refrigerant used, the evaporating temperature will mostly follow that rule, so find the refrigerant you're interested in on a comparator, find the temperature you want the product to be stored at, reduce this by 10c and convert to pressure.
    et voila as they say in france; there you have it.

  12. #12
    Join Date
    Oct 2009
    Location
    UK
    Posts
    8
    Rep Power
    0

    Re: Gas pressures

    Thanks for that bill, thats exactly whay I was asking to know.

Similar Threads

  1. High suction and liquid pressures
    By bth0mas20 in forum Trouble Shooting
    Replies: 4
    Last Post: 28-08-2009, 08:32 PM
  2. Oil pressures
    By HeathT in forum Trouble Shooting
    Replies: 2
    Last Post: 24-02-2009, 08:32 PM
  3. Throttling and Ideal compression:
    By Bharath Rajes in forum Technical Discussions
    Replies: 1
    Last Post: 14-02-2009, 11:04 PM
  4. Pressures at Evaporating & Condensing Sides
    By stephen.t in forum Technical Discussions
    Replies: 4
    Last Post: 31-01-2008, 12:34 AM
  5. condensation pressures
    By abcdefg1675 in forum Refrigerants
    Replies: 2
    Last Post: 25-07-2002, 02:18 AM

Posting Permissions

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