Heat gain sizing

[cswenson218]

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?

[cswenson218]

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.

[icemeister]

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

[Amjadd]

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