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BTU coil rating for OLD heater

Sam G.
Sam G. Member Posts: 12


  • Sam G.
    Sam G. Member Posts: 12

    We are working in a 50+ year old school. Steam heat. The complaint was not enough heat from old units. The blowers did not work in any rooms. They wanted steam baseboard installed under windows. When we opened the old units (many layers of paint)to get to the piping, found coils/blowers with pnumatic valves(disconnected long ago - valves in open position)When we plugged the blowers into an extension cord, they worked beautiful and quiet.

    Now I want to compare the potential output of the blowers to a heatloss on the room to see if there is enough heat without adding baseboard. The coils are 50 1/2" long, 4" high, 8" deep. 8 rows of tubing 4 top/4 bottom The units are left and right in the attached photos. (sorry I din't get a picture of the entire unit) Thanks Sam G
  • Sam G.
    Sam G. Member Posts: 12
    forgot photos

  • Unknown

    Not enough info to go by, the convection-type BB is relatively simple,,but is there any manufacturer name on these blower units?

  • Brad White
    Brad White Member Posts: 2,398
    Chances are

    a steam UV will have plenty of capacity on the assumption that it was designed by competent engineers that long ago (they tended to be conservative) and that the school envelope has been improved over the years as an added margin.

    Our experience (which should be verified independently always) is that a typical nominal 1,000 CFM unit ventilator would have about 80,000 BTUH capacity. Roughly 40,000 for the room heat loss (you check that out of course) and the remainder for the ventilation load, usually 500 CFM of outside air per classroom. This last variable can be anywhere from 375 to 500 in our experience, depending on local code or standard preference and of course the expected maximum class size.

    Not the be-all/end-all definitive answer but a point of comparison you may find useful.
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
  • Larry C_12
    Larry C_12 Member Posts: 9
    Steam or hot water?

    The 009 picture shows cast iron piping typical for steam, but 011 shows a mix of cast iron and copper. Was this system converted to forced hot water? If so, that might explain the loss of output.

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