Results 1 to 4 of 4
  1. #1
    Join Date
    Jun 2011
    Location
    MN
    Posts
    26

    Heat gain sizing

    We do some work at a sugar plant and they have "MCC" rooms that have motor controllers, circuit breakers, disconnects, and so on that all generate heat. A lot of heat. We are trying to do away with conventional AC with ducts and air handlers and stuff and go with refrigeration style evaps in the rooms...essentially treat each room as a walk in. How in the world do you figure heat gain for electrical controllers? We took an amp draw from one of the lines coming in and had 170 amps at 460 volts but the motors aren't actually in the room...just the controllers. They generate a lot of heat, but how do we figure how much?

  2. #2
    Join Date
    Jun 2011
    Location
    MN
    Posts
    26
    VFD controllers...I can take my camera on Monday and take pics...I can't even describe what exactly this equipment it. I just don't know.

  3. #3
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,076
    Here's an article which discusses heat rejection from VFDs:
    http://www.plantservices.com/article...lHeatLoad.html

    Another way, if there's existing powered ventilation, is to measure the air volume being exhausted and the temperature rise from ambient. Then use the sensible heat formula Q = 1.08 x CFM x DT

  4. #4
    I am also struggling to find the answer. Use below mentioned link and search 'HVAC' in PDF document. It will take you to a topic which lists down the components and heat dissipated by each one of them. Again, it requires a detailed study of a complete MCC unit and you electrical engineer would help you list down all the items. Good luck

    stevenengineering.com/tech_support/PDFs/45PNBMTR.pdf

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event