Choosing The Right Cabinet Cooler System

EXAIR Cabinet Cooler Systems provide heat protection for electrical enclosures, especially those in more “aggressive” environments. They’re durable & reliable, and unlike other devices (panel A/C, I’m looking at you), they’re impervious to environmental conditions and contamination…which they’ll also protect your electrical enclosures from. My colleague Jordan Shouse did a fabulous job of explaining how they work in a blog entitled (appropriately enough) “EXAIR Cabinet Cooler Systems – How Do they Work?” so I’ll get right to point of today’s blog, which is the selection process.

First, we need to calculate the heat load. If it’s for cooling a panel currently in operation, you need three things:

You’ll use the thermometer to “take the panel’s temperature”. See, we calculate the internal heat load (that’s the amount of heat generated by the components inside the panel) by using the difference between the internal air temperature, and the external air temperature. Since we’re essentially air conditioning the panel, it’s important to get air temperatures (from a thermometer) rather than surface temperatures (from a heat gun or similar instrument).

You won’t need the thermometer for this, but we’ll also need to know the maximum ambient temperature in the area where the panel is installed. This is to calculate the external heat load, and also determine if a High Temperature model is needed (more on that in a minute).

The tape measure is to get the length, width, and height of the panel. We also need to calculate the heat transfer surface area. A ruler or yardstick would work as well.

If there’s something cooling the panel already – whether it’s panel A/C, fan circulation of environmental air through the panel, etc. – we’ll need to know about that too, because you’ll be removing that for optimal performance of the Cabinet Cooler System.

Once you have all that, you can enter the data (and a few other things, which I’ll get to momentarily) at the above link to the Sizing Guide. If you’re a DIY type person (or control freak…no judgment from ME on that), there’s also a link there to our new Cabinet Cooler System Calculator. You can also print a copy of the Sizing Guide and email it or fax it in. Or…you can call me with the data. It only takes a minute to do the calculation, and we do it over the phone all the time.

Next, we need to know about the environment in which it’ll be installed, so we can specify certain parameters like:

  • NEMA rating. We make Cabinet Coolers for three distinct ratings, depending on the environment in which they’ll be installed.
    • NEMA 12 means it’s dust tight & oil tight, indoor duty. If no liquids or corrosives are present, this is probably what you’re looking for.
    • NEMA 4 means it’s dust tight, oil tight, splash resistant, indoor/outdoor duty. These have a low pressure relief valve for the Vortex Tube’s hot flow, and the exhaust from the panel, to maintain the splash resistant integrity of the panel.
    • NEMA 4X systems meet all requirements for a NEMA 4 rating, and are made of Type 303 Stainless Steel for corrosion resistance. We also make them in Type 316 Stainless Steel for higher levels of corrosion resistance, which is oftentimes specified in food and pharmaceutical environments.
  • Ambient temperature. If they’re going to be installed in areas where the temperature can exceed 125°F, there are some internal components made of plastic & buna that aren’t rated for that. In those cases, we specify a High Temperature Cabinet Cooler, where we replace those with components made of brass and Viton, respectively. Those are good for up to 200°F environments.
  • Atmospheric contaminants. All of our systems are, at a minimum, oil & dust tight per the above NEMA ratings. If a panel isn’t completely sealed – maybe there’s a cable bundle going through a loose grommet, or the door/front panel isn’t gasketed – then airborne stuff that you ideally want to keep away from sensitive electrical/electronic gear can still make it in. For those, we have two options:
    • Continuous operating systems will provide cold air flow for cooling and positive purge as long as compressed air is flowing to the Cabinet Cooler. That’ll keep the bad stuff out, but it’ll also get your panel colder than it needs to be, and you’ll pay for that with the increased cost of the full rated compressed air flow.
    • Non-Hazardous Purge systems allow Thermostat Control to turn off the compressed air flow when it’s not needed, and still pass 1 SCFM through the Cabinet Cooler (instead of full flow) when the internal temperature is at or below the Thermostat setpoint. These cost considerably less to run than Continuous Operation systems.
  • Thermostat Control. Agencies like Compressed Air Best Practices and the Compressed Air Challenge include panel cooling on their list of inappropriate uses of compressed air – EXCEPT when they’re thermostat controlled. EXAIR uses Solenoid Valves operated by bimetallic thermoswitches with superior response times, so the Cabinet Cooler doesn’t continue running once it’s cooled the panel to the setpoint temperature, and (more importantly) comes on as soon as the temperature rises above that setpoint to further guard against heat damage. They’re available in 120VAC, 240VAC, and 24VDC options.
The Thermostat’s (left) leads are spliced into the Solenoid Valve’s (bottom right) ‘hot’ lead, which essentially makes it an automatic temperature controlled ‘on/off’ switch for the Cabinet Cooler System. NEMA 4/4X versions include mounting hardware (top right).
  • Thermostat Control part 2. There are situations where the ability to change the regulated temperature is desirable. While the Thermostat’s setpoint can be changed, EXAIR’s ETC Electronic Temperature Control allows you to change it, at the push of a button. It also gives a continuous display of the actual temperature inside the panel that can alert operators to a potential overheating situation before the alarms start going off, or, if there are no alrms, before all those expensive electronic devices start to fry.
ETC Electronic Temperature Control can be used in a wide variety of applications.

EXAIR’s Cabinet Cooler Promotion also started June 1st if you’re interested in purchasing one for your process. For a limited time, you can order any of EXAIR’s Cabinet Cooler® Systems and get a FREE AC Sensor with purchase! Check it out here.

If you’d like to discuss the ease at which you can provide safe, effective, and reliable heat protection for electrical panels in almost any environment, give me a call.

Russ Bowman, CCASS

Application Engineer
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UL Classified Certification for HazLoc Cabinet Coolers

Although history only records back so far, I am certain (based on my experiences with sharp and heavy objects) that humans have been injuring themselves with tools, and the stuff they make with them, since the beginning of time.  In fact, recorded history DOES bear this out…the famous Code of Hammurabi (circa 1750 B.C.) set specific amounts of compensation for specific injuries, as did laws from all over the ancient world, from the empires of Rome to China.  Since then, we’ve come a long way in regulating safety not only for the worker in the workplace, but in public places, homes, and workplaces where manufactured products are used.

UL LLC (or Underwriters Laboratories, as they were known throughout the 20th Century) is a safety consulting & certification company founded in 1894 by an electrical engineer named William Henry Merrill.  A year earlier, an insurance company hired Merrill to perform a risk assessment and investigation of new potential clients…George Westinghouse and Nikola Tesla, the proprietors of the Palace of Electricity at the 1893 Chicago World’s Fair.  It was this experience that made him realize the potential for such an agency to test and set standards for product safety at the dawn of a new age of technology development.  And 120 years on, the benefits in safety & protection have been proven many times over.

If a product or device carries one of these markings, it’s been evaluated for safety by top professionals in the field.

One of the more critical accreditations that a manufacturer can receive for a product is the UL Classified Mark.  This differs from other markings (like the ones shown above for Certified, Listed, or Recognized) in that Classification means that samples of the product were tested & evaluated with respect to certain properties of the product.

EXAIR’s new Hazardous Location Cabinet Cooler Systems bear the UL Classified Mark.  This means they meet the stringent UL requirements for installation on purged electrical enclosures in specific classified areas:

  • Class I Div 1, Groups A, B, C and D
  • Class II Div 1, Groups E, F and G
  • Class III

EXAIR Hazardous Location Cabinet Cooler Systems maintain NEMA 4/4X Integrity and are CE Compliant.

When choosing products for use in classified areas, it’s critical to ensure safety through compliance, and the HazLoc Cabinet Cooler Systems allow you to do that, with simplicity and reliability.  If you’d like to discuss an enclosure cooling application, in or out of a classified area, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Class III Hazardous Areas

The National Electrical Code, or NEC, classifies hazardous areas into three different categories; Class I, Class II, and Class III.  To use equipment in or around these types of areas, caution has to be taken in order to not cause an explosion or fire.  In the U.S., the Underwriter’s Laboratory, UL, can certify products that can be used safely in these hazardous areas.  EXAIR received our UL Classification for our new product line; the HazLoc Cabinet Cooler Systems.  Under certain guidelines, the HazLoc Cabinet Coolers can be used in Class I for gases and vapors, Class II for flammable dust, and Class III for ignitable fibers and flyings.  In this blog, I will be discussing the Class III classified area.

For a fire or an explosion to occur, we need three things as described in the fire triangle; oxygen, fuel, and an ignition source.  For Class III areas, that fuel is a build-up of material like fabric lint and fine wood shavings.  These small fibers can float and collect on equipment in the surrounding areas.  This collection of material can easily ignite and cause a fire from a spark or a heat source, like kindling.  These fibrous materials and flyings are not explosive, but as a collection, they are a fire hazard; the reason for the Class III designation.  This newest hazardous classification is generally located within the textile and woodworking industries.

The ignition source (the second leg of the fire triangle) is generally from electrical equipment, heat, and static.  Arcs and sparks from motors, contactors, and switches can easily ignite Class III materials; as well as high temperatures from equipment.  NEC and UL segregate this hazardous location into two divisions.  Class III Division 1 is in an area where fibers/flyings are handled, manufactured, or used.  Class III Division 2 is where the fibers/flyings are stored or handled other than in the process of manufacturing.  In both divisions, it is important to protect your electrical systems from these small fibers floating in the surrounding air.

EXAIR's Hazardous Location Cabinet Cooler

The EXAIR HazLoc Cabinet Cooler Systems are designed to keep your electrical panels cool within hazardous areas like Class III because system shutdowns from electrical overheating are costly and potentially dangerous.  If you would like to discuss the details about the EXAIR HazLoc Cabinet Coolers, an Application Engineer at EXAIR will be happy to help you.


John Ball
Application Engineer
Twitter: @EXAIR_jb