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Owner Jim Lavallee P+H

Lavsplumbing
Lavsplumbing Member Posts: 2
What is the origin and definition of the manual J calculation?

Comments

  • Steamhead
    Steamhead Member Posts: 15,262
    It's also known

    as a "heat-loss calculation".



    I believe it originated with the American Society of Heating and Ventilating Engineers (ASHVE) which later added refrigeration and air-conditioning and became ASHRAE.



    Originally the calculations were done with pencil and paper, which probably explains why so much equipment is oversized- no one wanted to take the time to do the calcs. But the personal computer revolution has brought us programs that you can install on a laptop and take to the job with you, so there's no more excuse for not calculating every job.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Lavsplumbing
    Lavsplumbing Member Posts: 2
    Manual J definition

    What is the definition of manual J?
  • Steamhead
    Steamhead Member Posts: 15,262
    J is

    the letter they used to name the heat-loss calculation procedure manual. It's just a name, nothing special about it.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
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