# Calculating cooling required in electrical panel box

I have a single electrical distribution panel in an insulated metal panel building (a standalone shed) which has no active cooling or air vents. I need to determine whether the latter are required in a climate that has an average high and low temperatures in July of 22.6 and 7.0 degrees Celsius, respectively. A temperature of 28.5 has occurred in July in the recent past.

• The total calculated capacity of the steel distribution panel is 414 amps and the MCB rating is 100A (if this matters, I don't know). The Mains Breaker is listed as 160A/230/400V.

• The surface area (A) of the metal panel box is 0.855 m2.

I need to understand how to calculate the maximum heat that will be emitted from this panel.

By my calculations, with a 1 degree C temperature difference between the outside and the inside of the room (not the panel), the heat transfer is 41.9 Btu/hour (the total surface area = 129 m2).

My question is, in July will the room temperature exceed 40 degrees C with the heat emitted from this electrical panel?

• you need to know the heat load in the box. How many amps is not it. And the room temperature is a completely different question. Nov 7, 2023 at 1:49
• "My question is, in July will the room temperature exceed 40 degrees C WITHOUT the heat emitted from this electrical panel?" Do you record the temperatures? should be easy enough. Nov 7, 2023 at 8:16
• The issue really is how much heat can I expect this panel to emit? The total Watts calculated = 105,760. This is based on each circuit at its rated amperage and voltage. In reality it will never be maxed out. Is there a safe rule of thumb I can use to determine how many watts (which can then be considered heat energy) will be emitted? I can then add it to my building envelope heat transfer calculation to determine if the interior temperature will exceed 40C. Thanks for your help! Nov 7, 2023 at 14:33
• 105,000 watts is the current flowing through the wires, you needs the i-squared-R losses in the panel. 105 kW would be about 35 kitchen ovens running flat out, you need a sense of scale here. Nov 7, 2023 at 16:39
• There must be industry guidelines for this.
– Drew
Nov 8, 2023 at 14:38