Non Hazardous Purge Cabinet Cooler Systems

Last fall, when our youngest “flew the coop” and moved into a dormitory to begin his college experience, my lovely bride and I also embarked upon an exciting adventure: finding, purchasing, and moving in to our “empty nest” dream house.  While packing up the contents of the house where we had raised a United States Marine AND a hippie college student, I moved my trusty laptop from its perch on a desk in a dark basement corner, where it had resided, in that one spot, for more than a couple years.

As I was looking for its carrying case, I noticed the fan grill was almost completely obscured with more than a couple years’ worth of environmental contamination (or dust).  I vacuumed out the grill, but wondered how much more environmental contamination (dust) had made its way into the deep recesses of the laptop…and more importantly, what might it be doing to the sensitive electronics inside my trusty internet browsing device?

If a computer’s fan in a residential environment can get this dusty, imagine how much worse a control panel on a factory floor can get.

I know I’m not telling you anything you don’t already know, but electronics and dust don’t mix.  We have this conversation a LOT with callers inquiring about our Cabinet Cooler Systems.  The protection they offer against environmental contamination is integral with the protection they offer against heat.  In the panel cooling market, our Cabinet Cooler Systems are unique in that respect: a total protection solution.

When properly installed on a sealed enclosure, the only thing the inside of that enclosure is ever exposed to is cold, clean, moisture free air.  But what if the enclosure can’t be completely sealed?  One option is to use a Continuous Operation Cabinet Cooler System.  It works just as the name implies:  cold air is continuously flowing into the enclosure, creating a constant purge flow…if that cold air is blowing out of any openings in the enclosure, there’s no way for environmental contamination to get in.  Problem solved.

Well…almost.  Something else I’m sure you already know is, compressed air is costly.  Organizations like the Compressed Air & Gas Institute (CAGI) and the Compressed Air Challenge (CAC), who are devoted to optimizing industrial use of compressed air, have lists of “inappropriate uses of compressed air”, and panel cooling is on that list…EXCEPT when they’re thermostatically controlled.  At EXAIR, we couldn’t agree more, and if a caller asks any of us Application Engineers about a Continuous Operation Cabinet Cooler System, they’re inviting us in to a conversation about that.

Sometimes, the initial question is cost…well, we have to pay for the components that make up the Thermostat Controls, so we ask our customers who want those products to as well.   A quick conversation about the operating cost of continuous operation vs thermostat control is usually all that’s required in those cases.

Other times, a panel that can’t be sealed is installed in a particularly dusty or dirty environment, and they want the continuous flow of cold air, as described above, to keep those contaminants out.  A Continuous Operation Cabinet Cooler System will, of course, do that.  But EXAIR wants you to get the most out of your compressed air use, so we developed a “best of both worlds” solution: Non-Hazardous Purge Cabinet Cooler Systems.  Here’s how they work:

  • Based on a few key pieces of data that you can submit in our Cabinet Cooler Systems Sizing Guide, we’ll specify the appropriate Cabinet Cooler System to manage that heat load.
  • The system will be thermostatically controlled: a bimetallic Thermostat, mounted inside the panel, will open and close the Solenoid Valve plumbed in the compressed air supply to operate the Cabinet Cooler as needed to maintain temperature inside the panel.
  • The Solenoid Valve is modified to pass a small amount of air flow (1 SCFM) even when it’s closed.  This saves you from using the full rated air consumption of the Cabinet Cooler when cold air isn’t required, and still maintains enough purge air flow to prevent environmental contaminants from entering a less-than-ideally-sealed enclosure.
Whatever you do, DON’T do THIS to your panel.

The Non-Hazardous Purge option is just one way that EXAIR Corporation can help you address specific environmental challenges that may be presented in electrical and electronic panel cooling applications.  If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Hazardous Location AND Overheating Electronics? We Have You Covered!

Here in Ohio, we like to think we know a lot about the weather. Did you know there are more than 4 seasons? Heck, we have at least two Winters, and then a Pre-Summer, Spring, Summer, Heat is still coming – make it stop season, and Fall. Don’t forget the construction season where the lovely orange cones and barrels bloom on every major roadway, and then we also like to throw in brood weeks for the cicadas every now and then. Yeah, we get a full gambit of weather and the past week has brought out some heat. I know this isn’t just Ohio, we get calls from around the globe of atmospheric conditions that have caused issues within control panels. Some of these panels are in areas where the No Smoking sign is more than just a suggestion to better your health.

1 – Dust Explosion

That’s right, there are areas in manufacturing facilities that are governed by the standard due to a variety of conditions resulting in what is known as Hazardous Locations. NFPA and UL have a list of standards breaking these down into separate Classes, Divisions, and Temperature Classes. If you want all the details, the NFPA code is around 908 pages, cover to cover. The Classified UL mark shown below is one way of knowing that a product has been tested to these stringent standards and is okay to use in clearly marked environments.

UL Classified Markings

EXAIR offers Cabinet Cooler Systems that will meet these stringent standards and keep your enclosures cool in order to keep your production up and running. The top three tiers that we meet are:

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

The HazLoc Cabinet Cooler Systems are available in 8 different cooling capacities from 1,000 Btu/hr to 5,600 Btu/hr. and are manufactured to work in conjunction with a purged and pressurized control system. As well as with or without thermostatic control.

EXAIR’s Hazarous Location Cabinet Cooler Systems maintain Type NEMA 4/4X Integrity and are CE Compliant.

If you would like help sizing the correct system for your electrical panels, feel free to use the link, or contact an Application Engineer to discuss the applications and get one sized while on the phone with us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Dust explosion 05.jpg, Hans-Peter Scholz, October 7, 2009, retrieved from https://commons.wikimedia.org/wiki/File:Dust_explosion_05.jpg

Summer is Coming: EXAIR Cabinet Coolers Save Your Electrical Cabinets from Overheating

The pool is open, the garden is tilled, it must mean summer is coming. This year, I’m gearing up for a hot one. My love for spicy food is already well documented here on the EXAIR Blog, and this year it’s going to be the hottest one yet! In the garden for this year we have Purple Ghost Peppers, “regular” Bhut Jolokia (Ghost peppers), White Moruga Scorpion, Purple Ghost Scorpion, Bhutlah Scorpion, and a selection of “milder” peppers and other veggies for when I’d rather not melt my face off while eating. Needless to say, you should proceed with caution when eating salsa at my house. It’s going to be heating up in my kitchen at the same time your electrical cabinets also begin to overheat. Not to worry, EXAIR has the tools you need to keep things cool.

Some of what is in store for this year’s garden, acclimating to the “real’ sunshine in late April

EXAIR’s Cabinet Cooler Systems were designed specifically to rectify these issues within your facility. Utilizing Vortex Tube technology, the Cabinet Cooler produces cold air from an ordinary supply of compressed air. This cold air keeps the enclosure free of debris and moisture and is easily installed in minutes through a standard electrical knockout. Here is a short video that shows just how simple it really is. The Cabinet Cooler Systems are available with Nema 12 (IP54) ratings and are also available in Aluminum, 303 Stainless Steel, and 316 Stainless Steel construction for Nema 4/4X (IP66) rated enclosures. For systems that are not able to be mounted on top of the cabinet, we also have Side Mount Kits available in Aluminum, 303 Stainless, and 316 Stainless. This year, EXAIR also introduced a new line of Hazardous Location Cabinet Coolers for use in classified areas.

Many of our customers experience seasonal overheating problems with their cabinets. Cabinet Cooler systems are a perfect solution for electrical panels which start to fault out in may or June and continue to cause chaos through September or October. They are quick to install, maintenance free and can be purchased with a thermostat control so they turn off in October and back on in May. You’ll hardly even remember its there and you won’t miss the electrical problems normally associated with a hot summer.

These systems are available with cooling capacities of anywhere from 275-5,600 Btu/hr. To make things much easier for you, we offer a Cabinet Cooler Sizing Guide that will allow us to recommend the most suitable model for your cabinet. With a few quick measurements, we’ll be able to determine the exact heat load that we’ll need to dissipate and offer you a quick and easy solution.

If you experienced heat related issues on electrical panels last year, or just want to talk about spicy food and gardening, contact an Application Engineer today and we’ll be happy to help. Don’t wait until it’s too late, EXAIR’s Cabinet Cooler is the simple solution for maintaining the temperature inside of your electronic enclosures.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

The Basics of Calculating Heat Load for Cooling Electrical Cabinets

Is your electrical cabinet overheating and causing expensive shut downs? As spring and summer approach, did your enclosures have seasonal overheating problems last year? Is your electrical cabinets AC Unit failing and breaking down? Then it may be time to consider EXAIR Cabinet Coolers Systems. These systems are compressed air powered cooling units designed to keep your cabinet cool in hot environments. Major benefits include no moving parts to wear out, UL listed to maintain the NEMA integrity of your enclosure (also CE compliant), they are simple and quick to install and they reliably turn on and off as needed (perfect for solving seasonal overheating).

Just one question then; how do you pick which Cabinet Cooler is best for your application? It’s time to bust out ye ole trusty calculator and crunch some numbers. Keep in mind that the following calculations use baselines of an Inlet air pressure of 100 psig (6.9 bar), compressed air temperature of 70F (22C), and a desired internal temp of 95F (35C). Changes in these values will change the outcome, but rest assured a Cabinet Cooler system will generally operate just fine with changes to these baselines.

How the EXAIR Cabinet Cooler System Works


Before we dig right into the math, keep in mind you can submit the following parameters to EXAIR and we will do the math for you. You can use our online Cabinet Cooler Sizing Guide and receive a recommendation within 24 hours.

There are two areas where we want to find the amount of heat that is being generated in the environment; this would be the internal heat and the external heat. First, calculate the square feet exposed to the air while ignoring the top. This is just a simple surface are calculation that ignores one side.

(Height x Width x 2) + (Height x Depth x 2) + (Depth x Width) = Surface Area Exposed

Next, determine the maximum temperature differential between the maximum surrounding temperature (max external temp) and the desired Internal temperature. Majority of cases the industrial standard for optimal operation of electronics will work, this value is 95F (35C).


Max External Temp – Max Internal Temp Desired = Delta T of External Temp

Now that we have the difference between how hot the outside can get and the max, we want the inside to be, we can look at the Temperature Conversion Table which is below and also provided in EXAIR’s Cabinet Cooler System catalog section for you. If your Temperature Differential falls between two values on the table simply plug the values into the interpolation formula.

Once you have the conversion factor for either Btu/hr/ft2, multiply the Surface Area Exposed by the conversion factor to get the amount of heat being generated for the max external temperature. Keep this value as it will be used later.

Surface Area Exposed x Conversion Factor = External Heat Load

Now we will be looking at the heat generated by the internal components. If you already know the entire Watts lost for the internal components simply take the total sum and multiply by the conversion factor to get the heat generated. This conversion factor will be 3.41 which converts Watts to Btu/hr. If you do not know your watts lost simply use the current external temperature and the current internal temperature to find out. Calculating the Internal Heat Load is the same process as calculating your External Heat Load just using different numbers. Don’t forget if the value for your Delta T does not fall on the Temperature conversion chart use simple Interpolation.

Current Internal Temp – Current External Temp = Delta T of Internal Temperature
Surface Area Exposed x Conversion Factor = Internal Heat Load

Having determined both the Internal Heat Load and the External Heat Load simply add them together to get your Total Heat Load. At This point if fans are present or solar loading is present add in those cooling and heating values as well. Now, with the Total Heat Load match the value to the closet cooling capacity in the NEMA rating and kit that you want. If the external temperature is between 125F to 200F you will be looking at our High Temperature models denoted by an “HT” at the start of the part number.

From right to left: Small NEMA 12, Large NEMA 12, Large NEMA 4X

If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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