Heat load calculation for the control cabinets

[makbhure]

I have to give inputs to HVAC engineer regarding heat loads in the control room.The control room contains the PLc cabinets and Lighting.How shall i calculate the heat loads for a PLc cabinet.The cabinet is having AB make PLC,isolation transformer,power supply and terminals.CAn anybody help me in calculating this.Thanks in advance.

 

[jbartos]

Suggestion: Usually, one considers the input watt power of the cabinet or its components and subtracts watt power supplied to loads from the cabinet. This watt power difference usually dissipates into heat.

 

[wired1]

the A/C mfrs have good calcs in their catalogs. i've used kooltronics and mcclean-midwest successfully. one or both has a free program you can download. these are meant to size an a/c unit for the cabinet, but i'm guessing the principles would be the same for multiple cabinets in a room. use the efficiencies given by the plc mfrs, lighting fixtures, etc. to calculate how much power goes into heating the cabinet(room) as jbartos says.