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Max btus for 1\" copper?

Eric Johnson
Eric Johnson Member Posts: 174
What is the maximum number of btus that you can get through 1" copper? And as a practical matter, would it make any sense to connect a boiler that exceeded that number to a one-inch copper supply and return line?


  • David Sutton_6
    David Sutton_6 Member Posts: 1,079

    Based on a 20° temp drop 1 gallon per min of flow will transport 10,000 BTU's and a 1 copper pipe will handle 8 GPM
    8 x 10,000= 80,000

  • ALH_4
    ALH_4 Member Posts: 1,790
    Velocity and Delta-T

    The limitation is based on velocity in the pipe. Conservatively you could run 10gpm through a 1" diameter pipe. With water, you can move approximately 5000 btu per degree delta-T between the supply to the return in a 1" pipe. 20°F dT gives you 100MBH. 30°F dT gives you 150MBH. The btu carrying capacity of the pipe depends on the dT your system is designed for.
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