Heat, dirt, and moisture are natural enemies of electrical and electronic gear. Dirt and moisture are relatively easy to eliminate as dangers: just seal up the enclosure so they can’t get in. Heat, though, is a real “apex predator.” Whether the enclosure is sealed or not, the components inside will generate heat if they’re energized. And no matter what, the enclosure will get as hot as its surroundings in time, as long as the Second Law of Thermodynamics is in effect (spoiler alert: it’s immutable.)
So how do you keep the components in those panels cool? If the environment is clean enough and the temperature and humidity aren’t too high, fans can circulate cooling air from the environment through the panel. These are readily commercially available starting under $100.00, and generally won’t cost any more than about $50.00 a year in operating costs (electricity.) If the environment is climate controlled and relatively free of contaminants, you can’t beat them. If you’re on a desktop computer, and it hasn’t burned out, there’s your proof.
Many, if not most, industrial panels, though, are in areas where fan cooling just won’t cut it. Not only will those aforementioned natural enemies like dirt & moisture be allowed in, they’ll be DRAGGED in. Luckily, modern technology presents us with a number of options, depending on the particulars of the environment. The following are some details on “the usual suspects”, and a table with total cost of ownership:
Panel air conditioners work on the refrigerant cycle and are capable of the highest cooling capacities of the methods detailed here. They’re also the most expensive, with a typical annual cost of over $1,100.00.
Air-to-air heat exchangers transfer heat continuously through a sealed, hollow tube by vaporizing and condensing a refrigerant-type fluid. Instead of using compressors with electric motors and other mechanical components with lots of moving parts, they rely on capillary action to effect the phase changes. They can’t cool below ambient temperature, but they are the least expensive of these, coming in at around $370.00 in annual cost.
*Cold air (from the environment) causes the refrigerant to condense to a liquid.
Liquid-to-air heat exchangers work an awful lot like a car radiator: they circulate liquid (usually a water/glycol mix, like anti-freeze) through a heat exchanger/heat sink inside the panel and then through a heat exchanger outside the panel. Like the fan and refrigerant-based coolers, their cooling performance drops as the ambient temperature rises, except for the ones that use chilled water. In facilities that already have chilled water, that might not be a big deal, but if you need one that comes with the chiller, they can get pretty expensive. And, you still have the maintenance & durability issues that come with any refrigerant-operated cooler. Liquid-to-air systems can run as low as ~$425.00 a year in total cost, for the ones that don’t need chilled water.
Thermoelectric coolers use the Peltier effect: when voltage is applied to two electrodes connected to a semiconductor, heat is transferred from one side to the other. Their compact design with no moving parts makes them popular for high-performance gaming computers (like the one my son spends WAY too much time on), small coolers (wine experts like them because they don’t cause any vibration which can affect the wine’s quality), and certain lab, medical, and laser cooling equipment. They have a limited cooling capacity, and because electric current generates heat, that gets added to the overall heat dissipation. The annual cost for these is around $950.00.
EXAIR Cabinet Cooler Systems can be installed in minutes, have no moving parts to wear, no electric motors to burn out, aren’t affected by environmental contaminants or humidity. In fact, of all the methods available for panel cooling, they have the widest range of where they can be used:
They do require an adequate supply of compressed air, which makes up the bulk of their total cost of ownership, which is around $410.00 a year.
I’ve mentioned cost of ownership several times, so I had better get to what that means: it’s the cost of the equipment itself and installation (spread across the effective life of the equipment), plus the annual maintenance & operating costs. Here’s a table with a comparison of the panel cooling options above:
If you have electrical or electronic panels that need heat protection RIGHT NOW, we can help. ALL of our systems are in stock and available for same-day shipment. We can even help out with determining which one is right for your needs with the information from our Sizing Guide, or you can do it yourself with our online calculator. If you want some help with it, give me a call.
Russ Bowman, CCASS
Application Engineer
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