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JHK Member Posts: 16
As a rule of thumb how many cfm is required per 1,000 btu's output for a gas furnace?


  • Empire_2
    Empire_2 Member Posts: 2,343
    Funny Q:? in that:

    Are you talking Forced air, boiler, what do you want your delta T to be?, Application etc...  A/C sometimes ratted at 400cfm/ton, but not always due to conditions that have to be met.  I have seen cooling specs. for 325cfm/ton.  If your Q? for cfm also must have the size of duct, it's current profected static pressure etc..

      I guess I would like to know what you are trying to do???

    Mike T.
  • J Heritage
    J Heritage Member Posts: 27
    Depends upon efficiency

    80% is abour 130 cfm per 10,000 btu

    90% is about 150 cfm per 10,00 btu

    This is for heating airflow
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