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  1. #1
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    On coil / off coil temperature



    hi all i am new to HVAC . i just want to how to find out on / off coil temperature.

    for example : Outdoor temp 45 deg and 90 RH
    Room temp 24 deg and 50 RH
    MY AIRFLOW IS 16250 CMH
    SENSIBLE LOAD 54.85 KW



  2. #2
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    Re: On coil / off coil temperature

    Quote Originally Posted by GIRI View Post
    hi all i am new to HVAC . i just want to how to find out on / off coil temperature.

    for example : Outdoor temp 45 deg and 90 RH
    Room temp 24 deg and 50 RH
    MY AIRFLOW IS 16250 CMH
    SENSIBLE LOAD 54.85 KW
    on coil of AHU/FCU= air entering temperature
    off coil of AHU/FCU= air leaving temperature

  3. #3
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    Re: On coil / off coil temperature

    Quote Originally Posted by moideen View Post
    on coil of AHU/FCU= air entering temperature
    off coil of AHU/FCU= air leaving temperature

    Thank you moideen,

    I just want to know how you will finalise the on coil and off coil temperature. is there any regulation or formula..?

  4. #4
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    Re: On coil / off coil temperature

    .

    Rough rule of thumb is 10 degs difference.

    Air off is lower than air on and if it is 10 degs lower then
    the thing is working.

    (this is a rough rule of thumb that is a guide only)

    Regards

    Rob

    .
    .. ... -. .----. - / -- --- .-. ... . / -.-. --- -.. . / --. --- --- -..

  5. #5
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    Re: On coil / off coil temperature

    First you would have to determine what type of kit you are looking at.

    In your example above, for the indoor coil, the on coil temp would be 24 degrees for a recirculating unit and 45 degrees for a 100% fresh air unit...
    The off coil temp should then ideally be around 10 degrees below your room temp i.e. 14 degrees (assuming we are talking cooling and not heating...).


  6. #6
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    Re: On coil / off coil temperature

    Quote Originally Posted by The Viking View Post
    First you would have to determine what type of kit you are looking at.

    In your example above, for the indoor coil, the on coil temp would be 24 degrees for a recirculating unit and 45 degrees for a 100% fresh air unit...
    The off coil temp should then ideally be around 10 degrees below your room temp i.e. 14 degrees (assuming we are talking cooling and not heating...).



    thank you all for your information

  7. #7
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    Re: On coil / off coil temperature

    Fresh AIr Ratio? Supply air flow?

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