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  1. #1
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    Normal Delta_T For Heat Pump System?

    What is the normally accepted range Delta T between supply & return on the heating side of a heat pump system? My new system was giving about 22F degrees when it was low 50's outside ambient, but barley gives a max delta of 10F when its low 40's outside. Thanks!

  2. #2
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    .

  3. #3
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    switch the fan to auto and system to heat
    Some Talk, Some Do
    Energy efficient and economical to operate are not synonyms
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  4. #4
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    Sounds very low. Typical 20+ at 30 out, close to 30 degree rise at 50 out with proper airflow.

  5. #5
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    with a bryant h/p and an electric air handler with no heat strips running i was getting a 32 degree F split with a 20 degree F temp. outside

  6. #6
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    My Nordyne will give me 20.3° at 17°.

  7. #7
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    Quote Originally Posted by BaldLoonie View Post
    Sounds very low. Typical 20+ at 30 out, close to 30 degree rise at 50 out with proper airflow.
    See the key words; Proper Airflow.

  8. #8
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    I had a new Lennox G71MPP furnace and XP14-042 heat pump installed a month or so ago. The Delta T at 55 degrees exterior temperature with the heat pump running was 40.

  9. #9
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    Quote Originally Posted by BBDartCA View Post
    What is the normally accepted range Delta T between supply & return on the heating side of a heat pump system? My new system was giving about 22F degrees when it was low 50's outside ambient, but barley gives a max delta of 10F when its low 40's outside. Thanks!
    Call 'em back!

    What's you model numbers?

  10. #10
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    Quote Originally Posted by BBDartCA View Post
    What is the normally accepted range Delta T between supply & return on the heating side of a heat pump system? My new system was giving about 22F degrees when it was low 50's outside ambient, but barley gives a max delta of 10F when its low 40's outside. Thanks!
    Tech Operating Data for my 3-ton, 14 SEER, 9 HSPF pump:

    Ambient-------Temp after indoor coil
    Temp-------(based on 70F return air temp)

    60F---------------105.8F
    50F---------------101.5
    40F---------------97.1
    30F---------------93.4
    20F---------------89.9
    10F---------------86.2
    0F----------------82.6


    Take care.

  11. #11
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    Quote Originally Posted by gary_g View Post
    Tech Operating Data for my 3-ton, 14 SEER, 9 HSPF pump:

    Ambient-------Temp after indoor coilambient usually refers to outdoor temp unless otherwise specified
    Temp-------(based on 70F return air temp)

    60F---------------105.8F
    50F---------------101.5
    40F---------------97.1
    30F---------------93.4
    20F---------------89.9
    10F---------------86.2
    0F----------------82.6
    if I were to read CAREFULLY you are saying that, for example, an ambient(outdoor) temp of 0*F with a return air temp of 70* gives you a supply temp of 82.6*F or 12.6* temp rise/delta T

    Take care.
    .

  12. #12
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    Quote Originally Posted by pacnw View Post
    .
    You are reading the columns incorrectly.

    Ambient temps are in the column going from 60F to 0F, with the corresponding coil temp in the column next to each ambient temp.

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