Thermodynamics of Panel Cooling

With more and more electronics being utilized in manufacturing areas, problems with heat and debris have become more of an issue compared to old school hard switching. When sizing up panel coolers, most customers think that it is the hot environment that is the heat load. Rightly so, it does present a heat load but its greatest effect is preventing heat generated by the internal electronics from getting out. Thus the inside panel temperature will be whatever ambient is plus whatever heat cannot permeate through the walls of the panel.

Energy, in this case heat energy, moves from a high energy source towards a lower energy source. The rate at which it will travel depends on the thermal conductivity of the material that it has to travel through and the temperature differential between one side and the other. Fiberglass batting has a low level of conductivity which is why it is used to insulate our homes. Electrical panels are made of steel which has a higher rate of thermal conductivity but still has some resistance.

To better understand the dynamics of the thermal process, lets assume the panel is not operating so there is no heat being generated inside. The internal temperature of the panel will be the same as the temperature outside the panel. Now when the panel is turned on, internal components begin to generate heat. Some of this heat is able to permeate through the panel walls at some given rate. As the heat energy being generated exceeds the rate it is radiated, the temperature inside the panel will rise.

Panel Cooling

When we do panel cooling calculations, we ask for the temperature inside the panel, the temperature just outside the panel, and the approximate panel dimensions. From that data we can calculate the amount of heat that is trapped inside.

We are coming up to the summer season and with it, overheating control panels. All of us at one time or another have opened the doors and positioned a fan to cool the electronics. This is not only a safety violation but coats the electronics with contaminants.


EXAIR has a cost effective alternative using compressed  air to introduce cool dry refrigerated air into the panel and exhaust the hot air out through the cooler itself. This provides a closed loop system preventing any condensation and debris from getting in.

Now is the time to start preparing for the summer heat wave they are predicting.  Give our application engineers a call with your data and they will calculate your cooling requirements. Or you can go online and fill out a form  and submit it electronically.

Joe Panfalone

Application Engineer
Phone (513) 671-3322
Fax (513) 671-3363

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