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  1. #1
    Join Date
    Jul 2008
    Location
    Houston,TX
    Posts
    32

    Goodman ? Grabbing for straws !

    Okay fellas this one has me banging my head against the wall and nothing seems right . Here is the scenario .New house (8 months old, Moved in in DEC.), new Condensing unit 3 ton Goodman model CLQ30-1B, new coil model CSCF3642N6AA, new airhandler also Goodman.
    I decided to give it a once over when I noticed it was having a hard time cooling the house down.
    I checked the pressures and they were as follows :
    90 psig suction
    225 (Liquid)
    suction line temp 61*
    liquid line temp 85*
    Evaporator temp of 53*
    Condensor temp 110*
    with these numbers my superheat would be 8* and my subcooling would be 25*.
    My first train of thought was flow rater was feeding too much refrigerant causing head to be low and suction to be high .What was alarming is that the .065 flow rater was still attached to the Cond unit. I thought something was up when I seen it out there.
    I called Goodman and spoke with a Technical assistance guy and he confirmed what I had thought . He told me that I most likely had a .078 flow rater installed and I needed a .065 in there. I mostly do commercial and Industrial and it has been along time since I had done any residential ,and I know alot of this have changed, so I wanted to call and make surebefore I changed anything.
    I decided to swap them out this morning and I pumped the unit down ,changed flow raters , pulled a 29" vaccum . Opened the valves and was running a 100 psig suction and a 300+ (Liquid) all with a 78* house. I start to wonder if I installed the flow rater in backwards ,so I reverse it and vac back dwn to 29", now 110 psig suction and 200(Liqiud) .
    House still having a hard time coming down to temp .
    Any thought or ideas would be welcomed ?
    I am tempted to put it back the way it was before and leave it , but a 53* coil seemed high to me when it should be 40!

  2. #2
    Join Date
    Jul 2008
    Location
    Houston,TX
    Posts
    32
    I am going to apply for pro membership when I get my 15 posts in !

  3. #3
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,627
    the side with the white seal goes in first high humidity will give a high suction also the 13 seer are running a higher suction you need to take a wet bulb temp and set your super heat or change to a txv

  4. #4
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,627
    what about your air flow probably to high

  5. #5
    Join Date
    Jul 2008
    Location
    Houston,TX
    Posts
    32
    I have a 20X25 R/A grille and a 12X12 in my bedroom. I did not measure the plenum,but it looked sufficent with about 18" flex attaching the 2.

    Are you saying the teflon seal goes facing the liquid line or against the distributor ?
    I can slow the velocity of airflow down by partially blocking off the R/A and see what that does.
    Thanks, I did not think of too much airflow !

  6. #6
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,627
    how did the existing come out was the teflon seal agaist the distributor if not it should have been

  7. #7
    Join Date
    Jul 2008
    Location
    Houston,TX
    Posts
    32
    When I pulled it apart it blew out and fell in the Aux pan.
    I guess some liquid must have bolied off and raise the pressure for m the vaccum that I had it in . R/A Plenum is 16X26 and attached to a 20X25 with a 16 " flex.

  8. #8
    Join Date
    Jan 2005
    Location
    USA
    Posts
    1,450
    Quote Originally Posted by mikebaker1129 View Post
    I am going to apply for pro membership when I get my 15 posts in !
    Good idea then you will get better help and access to a lot of really good information.
    "It's always controls"

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,907
    Well, first, you don't have a 3 ton A/C, thats a 2.5 ton unit.
    Second, 13 SEER units don't run 40°F coils.
    Did you check the actual air flow, or are you just guessing the CFM is correct.
    A 3 ton air handler moving 1200 CFM across that coil with a 2.5 ton condenser will run a higher vapor and head pressure.

    Verify air flow.

    Could be its under sized. Or was only sized to cool the house to 80 when its 100° outside.
    Contractor locator map

    How-to-apply-for-Professional

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

  10. #10
    Join Date
    May 2002
    Location
    Houston Texas
    Posts
    6,321
    Mike I see you are Houston so am I and several others. Don't block off the return change the fan speed to med-hi. Blocking the return will reduce air across the coil but will not slow down the velocity.

    Do you have a manometer or some way to check static pressure.

    That condenser is older than the coil so I would change to a TXV but it is to late to get one today. I think I have one but no sure what part of town are you in.

    When you say you pulled down to 29" I am assuming you are not using a micron gauge, if not you could have non-condensables in the line. Are you sure that the new piston is indeed the 65 and not the 78.

  11. #11
    Join Date
    Jul 2008
    Location
    Houston,TX
    Posts
    32
    I just checked pressures:
    84 psig
    250psig
    50*evap
    115* cond
    35*superheat
    28* subcooling
    Installing the .065 flow rater did not correct the issues.I am tempted to install the .078 for now and leave be for now .

  12. #12
    Join Date
    May 2002
    Location
    Houston Texas
    Posts
    6,321
    Hey BT missed that that was a2.5-ton the CLQ caught my eye went right by me. If this is a new house it is only sized for 95* maybe even 93* so 80 on a day like today is good.

    Since that is a 2.5-ton almost certain the installer did not change fan speed. Need to check static probably very high, you have flex and plastic grills?

  13. #13
    Join Date
    May 2002
    Location
    Houston Texas
    Posts
    6,321
    Just two more post and you can start hounding Bill, Robin and Twilli for pro status.

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