calculate heat rise in electronic cabinet

[glory452]

Hi everyone. I'm new to eng-tips.com. I came across this site during some google searching and I'm hoping someone can help me.

I'm an EE for a industrial controls company and I've been tasked with determining the maximum temperature in a steel electronic enclosure given an ambient of a:100 degF and b:0 degF. The electronic enclosure will sit atop a white colored roof.

I'm running some tests now to determine how much the cabinet temperature will rise due to the electronics in the enclosure.

I think there will be multiple components which contribute to the heat rise: ambient difference, radiated heat from the sun and heat self-generated by the electronics, but I really am unsure where to start. Thanks for any help!

 

[Compositepro]

It depends. For example, if the heat is generated at the top of the cabinet it will not move below the point it was generated by convection. So the temperature at the top of the cabinet will be higher than if the heat source were at the bottom. But if the heat source is at the bottom then the bottom temperature will be higher but the top temperature will be lower. A fan will help alot.