I have designed a simple control panel that has an internal heat load of 199 Watts.
Its a 72x36x24 Hoffman Enclosure. This control panel is in a temperature controlled
building. None the less the specification is requiring me to do a heat load calculation
with an environment temp of 50°C. All parts in my panel I have verified at rated for
50°C.

The client states that the Outside and Inside Temp shall be 50°C for my calculation.
I tried to explain that a temp of 50­°C outside an enclosure will never give the same temp at worst case
condition by using just a Fan. Just like a car. If a car outside temp is 50°C then inside temp will be at least 10° hotter, in
my case 55°C (132°F). By doing this I have now went over the parts rating. Any Suggestions how to describe/pass
my heat load calculations?


The only way to keep the panel at the same temperature at this worst case temp is to have a AC, which I don't need.
I'm I missing something? Any support will be greatly appreciated.

I'm using the Hoffman Cooling Analysis program for my Heat Load Calculation. Small Bio