heat calculation

I need to do heat calculation for a customers control panel.Does anyone have guidelines on how i should do the or even an example.

Thanks
jim cav

You will find a wealth of information on this subject at Hoffman.

Here is one article, there are many more plus sizing software if you need it.

http://www.hoffmanonline.com/stream_document.aspx?rRID=153965&pRID=153932

From bitter experience
1. Use fan and discharge to the cabinet. This way cabinet interiorer will be at a pressure greater than ******t. Dust will not leak into cabinet thru useless seals.
2. FILTER the fan inlet. The fan will stay clean and run longer. In addition you will not be pumping dust into cabinet. Make sure filter media has a pore size smaller than dust particles.

Yes I am thoroughly tired of cleaning improperly set up cabinets.
On other hand cleaning was job security (DOWNTIME)and there was added job security from changing out relays (MORE DOWNTIME) jam packed solid with dust.
Dan Bentler

Positive pressure to cabinets really does improve reliabiliy in dusty environments - but try to use clean air.

I did put a fairly large vfd drive in a cabinet and the sales engieer did advise me that the unit would loose a certain percentage as heat loss. In this case I recall it was about 1kw, so he spec'd the fan to.