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  1. #14
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,627

  2. #15
    Join Date
    Jul 2007
    Location
    Delaware
    Posts
    3,824
    Can you post a pic of the new inside unit? Let us see what the install looks like.
    Always here

  3. #16
    Join Date
    Apr 2012
    Posts
    10
    Quote Originally Posted by second opinion View Post
    Optimally would be using the correct design temperature. You have proven that it is over sized and your airflow is probably high giving you lower than normal DT and the charge is probably low.
    I do not know what you mean "correct design temperature"

    today was 102 and Saturday it will be 105

    The installing company said that 95 used to be the design temperature , but after last summer with 60 days straight over 100 degrees then they now design for 105

    as far as Delta T being low because fan speeds are too high...I have a variable speed blower that is low on 2 tons and high on 4

    the $ between a 3 T system and a 4 T system is not much and 1.5 tons low would not have been adequate and system would have run constantly on 3 T , costing me more in energy usage

  4. #17
    Join Date
    Apr 2012
    Posts
    10
    howdy

    I will get you some pictures of outside unit and inside unit install

    there was no central air in house before install on a 1950's house.

    there was a centrally located coat closet which I personally converted into an equipment closet

    It was a tight fit and a big effort to get 110 service , condensate drain and 3/4" gas service to unit

    every inch counted installing a 24 x 28 in wide furnace into a 29 x 30 inch closet

    used 1/4 cement board on walls to save space - plenty of return air from low returns on all sides and high returns on 3 sides

  5. #18
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,912
    If its maintaining 78 when its 12 outside in first stage, then a 3 ton would have been plenty big.

    A 3 ton would have cost less to use, then your 4 ton does.
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    How many times must one fix something before it is fixed?

  6. #19
    Join Date
    Apr 2010
    Location
    Minnesota
    Posts
    517
    10 deg delta is too low on 1st stage. I wonder if your fan is set up right? WHen you set the stat to fan on, then put on 1st stage cooling, is there a difference in the fan speed? It should remain at 50% fan in 1st stage.

  7. #20
    Join Date
    Dec 2002
    Location
    Arizona
    Posts
    4,366
    Quote Originally Posted by Night_Owl View Post
    the $ between a 3 T system and a 4 T system is not much and 1.5 tons low would not have been adequate and system would have run constantly on 3 T , costing me more in energy usage
    And yet your 4 ton unit runs 95% of the time on 2 tons, but the 3 ton would run constantly on 3 tons!

    Sorry your new unit is OVERSIZED!
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  8. #21
    Join Date
    Apr 2012
    Posts
    10

    Frown

    the dips that installed the system left all of the dip switches on default settings

    so, since they never came out, or even called me back all week, I just put on my big boy pants and removed the bottom cover of furnace and set the dip switches correctly

    was set to 5 ton default thus moving more air than what it should of for my tonnage

    lower delta T's and quieter fan as well

    was 106 on Saturday

    unit ran all day on 2 T , except would kick up to 4 T about 3 times an hour for about 3 min each time

    Id be a Happy Camper....

    .....except there is still some air leaking from where coil meets furnace and the unused condensate drain fitting on coil

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