Page 1 of 2 12 LastLast
Results 1 to 13 of 20
  1. #1
    Join Date
    Jul 2005
    Posts
    3
    Just replaced a 10 year old 10 Seer Trane system with new 12 Seer Trane system in my upstairs system. Both the compressor(1.5 ton) and the Air handler(2 ton) were replaced.

    The upstairs part of the house still will not cool down.

    While there are many things to consider, what bothers me the most is the lack of condensation on the freon lines at the new compressor. It appears to me that the new compressor just isn't getting the freon cold enough. This is true even at night when the heat gain is substantially less.

    The compressor for the downstairs system(4 tons) sits next to the new compressor and its freon line is cold and wet. The freon line connected to the new compressor is warmer(to the touch) and dry.

    Day or nite, the large downstairs AC system is draining a good amount of water while the smaller upstairs system is dry.

    I am thinking that since the upstairs system cannot cool the freon sufficiently to produce condensation, it isn't working properly.


    Thanks for any insights
    Mike


  2. #2
    Join Date
    Feb 2003
    Location
    S.W. PA
    Posts
    3,298
    quit running it get a tech to check it out
    sounds like low charge

  3. #3
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,513
    shut it down and call for help
    campressor may be on over load and it need the cool off before he gets there. if it is low charge you can damage the compressor by running it
    turn it off

  4. #4
    Join Date
    Jun 2003
    Location
    Jacksonville, FL.
    Posts
    4,313
    Call the co. that installed your system & tell them that it's still not working.

  5. #5
    You mentioned that its not getting cold enough and the condensation isn't really there, but are you sure that the system isn't undersized?

    I don't do exact heat calcs, I mean I don't calculate the windows and the Insulation in the attic, but I have faired pretty well at 400 sq ft. to a ton on my installs, Maybe its undersized.

  6. #6
    Join Date
    Dec 2004
    Location
    Derby City
    Posts
    3,958
    first of all, call a professional. second, rules of thumb do not, I repeat, do not apply. If only it were that simple.
    Everyone has a purpose in life..........even if it's to be a bad example.

    Seek first to understand, before seeking to be understood.

  7. #7
    did you pre-cool the freezone stuff before you put it in the system ? can't put it in hot

  8. #8
    Join Date
    Jun 2003
    Location
    Jacksonville, FL.
    Posts
    4,313
    Originally posted by diegocentral
    I have faired pretty well at 400 sq ft. to a ton on my installs
    Wow. That's almost as good as checking a charge by listening to a TXV with a screwdriver & a suction line temp. of 58.

  9. #9
    if your previous trane systems failed in 10 yrs, why would u make the same mistake twice.

  10. #10
    Join Date
    Jun 2005
    Posts
    83
    400 ft a ton, don't work. One house could have all glass another over insulated. Trust the J Manual to do the load calculation, guessing doesn't work.
    So I guess your installer guessed the size.Now it don't work.
    Call the contractor up see if he can guess what is wrong.

  11. #11
    Join Date
    Jun 2005
    Location
    SW Wisconsin
    Posts
    4,907
    It could be drawing extremely hot air into the return air from the attic. Check the return air temp and supply air temps. Have them check and seal the duct system. We need to know the temps, and the temp difference off the outdoor condenser, too!
    Post yuor temp results here.

    If that is not the problem then it could be too many things to list here. Copy the linked page and give it to the tech.

    http://www.udarrell.com/ac-trouble-shooting-chart.html


  12. #12
    I agree with udarrell. There is a very good chance that your return air is overheated. A leak in the attic is a poss. or Iv even seen where the attic insulation has become to old and setteled, loosing its insulative factor. Under charge is another poss. cause or undersized refrigerant pipeing. In any case call a tech out. The one who installed it should provide you the call back for free.

    P.S. Take a temp split (Delta T) Reutrn air temp vs. supply air temp. Whats the diffrence?

  13. #13
    Join Date
    Jul 2005
    Posts
    3
    Thanks everyone.

    Here is what I know now.
    Attic Temp 109
    Return Air at grill - 79
    Return Air at handler - 81
    Supply Air at handler - 66
    Supply Air at register - 67

    This morning, I had these results
    Attic Temp 90
    Return Air at grill - 79
    Return Air at handler - 80
    Supply Air at handler - 60
    Supply Air at register - 60

    I am confident the supply and return ducts are sealed and not leaking.

    I think my problem is the 15 degrees of cooling I recieve in the afternoon. I measured the airtemp in the handler return by attaching the thermometer to the filter inside the handler. The handler itself is not leaking air.

    So, in the afternoon, when the air handler box is 109 degrees, the air handler cannot produce 20 degrees of cooling.

    udarrell, I will be looking over your materials. Thanks.

Page 1 of 2 12 LastLast

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