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Boiler Sizing

SteamGuyDetroit
SteamGuyDetroit Member Posts: 1
in Strictly Steam
When removing a customer from district steam, does anyone have an old formula for sizing the boiler when the steam usage is known?
Example, if the worst case usage was January 2014 of 296Mlbs.

Comments

  • Fred
    Fred Member Posts: 8,542
    edited July 2016
    If you calculate the total EDR of all the radiators in the customers house/structure, then you can size the boiler based on that number.
  • Steamhead
    Steamhead Member Posts: 17,314
    Tell us more about the job- residential? Commercial? What type of heat transmitters in the rooms- or are they all fan-coils?

    Is Detroit shutting down its district steam system?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,208
    Don't forget to add a piping and pickup factor to the total EDR. Multiply the total EDR by 1.33 for insulated pipes or 1.5 for uninsulated pipes and then select the boiler from the D.O.E Heating Capacity rating column in the boiler literature. See pages 73-75 in The Lost Art of Steam Heating by Dan Holohan.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Fred
    Fred Member Posts: 8,542
    Alan (California Radiant) Forbes said:

    Don't forget to add a piping and pickup factor to the total EDR. Multiply the total EDR by 1.33 for insulated pipes or 1.5 for uninsulated pipes and then select the boiler from the D.O.E Heating Capacity rating column in the boiler literature. See pages 73-75 in The Lost Art of Steam Heating by Dan Holohan.

    I would suggest his quote include insulating the mains and any accessible run-outs/returns before I increased the boiler pick-up/piping factor.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    What sort of system is this-two-pipe, or one-pipe?
    If two-pipe, the pickup factor could be much lower than one-pipe. This assumes generous boiler piping, following the manufacturers requirements at a minimum, assuring dry steam at low ounces of pressure.
    Go with gravity, and forget using a condensate pump for best effect.--NBC
  • BobC
    BobC Member Posts: 5,495
    If you know the EDR of the installed radiation just select a boiler that has a SqFt of steam rating that is about the same or higher. That SqFt of steam already includes a 33% pickup factor for piping. If the piping is well insulated you can go below the EDR number, if it's all bare steel it should be insulated for good performance.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Peteys
    Peteys Member Posts: 79
    Would this be true if it also had an indirect water heater attached also?
  • SWEI
    SWEI Member Posts: 7,356
    Generally, yes -- at least in a residential setting.

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