Electrical Panel Heat Protection: Limitations of Fan Cooling

In preparation for some labor-intensive outdoor projects, I did some research into heat-related health risks, and their prevention. My first thought on prevention was getting someone else to do it, but my wife made a good case for “pride in ownership”, and I DO have a good many tools suitable for these projects. Also, I am notoriously frugal, so after getting a couple of estimates, I realized the value in a little DIY (do it yourself) and commenced planning.

High on that list of risks was the possibility of heat stroke. It’s recommended that the victim be taken to a cool space (someplace air conditioned, for example). Air flow (like from a fan) can help too, but only if they’re taken someplace where the ambient temperature is less that 95F (35C). If it’s that hot, the air flow can actually make things worse, since heat transfer requires a difference in temperature. If the cooling medium (air, in this case) is the same temperature as the object to be cooled (the human body, in this case), no heat will be transferred – and the heat stroke wins. That’s a bad day in the back yard.

This is, in fact, the exact same limitation with a popular method of electrical panel cooling: fans. We’ve been using mechanical methods of imparting motion to air for cooling purposes for a long, long time: Blowing on a spoonful of soup or a cup of coffee before a warm (but not scalding) sip, waving hand fans at oneself during indoor gatherings, installing electric fans in those same buildings, and the list goes on. Fans are inexpensive to purchase & operate, come in a variety of sizes & configurations, and are oftentimes used to circulate cooling air through occupied rooms, confined spaces, and, of course, electrical & electronic panel enclosures.

These are quite effective for panels with moderate-to-high internal heat loads, as long as the ambient area temperature is less than the temperature you wish to cool the panel’s internal air to. In those situations, the only real concern is the quality of the air in the environment. As you can see in the photo to the right, filters are an absolute “must”, and they’re going to require regular maintenance. This means cleaning or replacing the filters, as well as cleaning the fan grills and blades themselves. It’s still very likely that some of that dust is going to get inside the enclosure, and while we’re on the subject of environmental contamination, so will humidity. I probably don’t need to tell you that dirt and/or water, and electricity, don’t mix.

There are other methods of cooling (panel a/c, thermoelectric coolers, water cooled heat exchangers, heat pipes, etc.) that limit environmental contamination, but they’re still going to need periodic (oftentimes frequent) attention: filters will clog, refrigerant coils will get fouled and corrode, moving parts will wear, motors & switches will burn out, etc. Even with the advances made in refrigerant technology, the leaks that panel a/c and heat pipes are prone to are still bad for the environment.

If this sounds like your environment, and you’re looking for safe, dependable, durable heat protection, look no further than EXAIR Cabinet Cooler Systems. Using the Vortex Tube phenomenon, they generate cold air from your compressed air supply, with no moving parts to wear or electric devices to burn out. Systems are on the shelf & ready to ship in cooling capacities to 5,600 Btu/hr. We also “tailor-make” systems for higher heat loads, from stock products, that can usually ship right away as well. Once installed on a sealed enclosure, the only thing the internals of that enclosure are ever exposed to again is clean, moisture free, cold air. All of our Cabinet Cooler Systems come with an Automatic Drain Filter Separator – the only preventive maintenance that’s ever required for the systems is the periodic replacement of the filter’s particulate element.

Inside, outdoors, high temperature, dirt/dust/humidity, corrosive and classified environments are no problem for EXAIR Cabinet Cooler Systems

We can quickly and accurately specify a Cabinet Cooler System to meet your needs with just a few key pieces of information – you can fill out a Sizing Guide (or complete one online) and send it in to us, or you can call an Application Engineer with the data. It only takes a minute to do the calculations, and we do them over the phone all the time. Installation is straightforward and usually only takes a matter of minutes. We have a number of short “how to” videos on our website that cover all aspects of installation, and if you ever have specific questions or concerns, an Application Engineer is a phone call away. We look forward to hearing from you!

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Factors When Sizing a Cabinet Cooler System

Heat can cause real problems for electrical and electronic components, in a hurry…we all know that.  Fortunately, we can also specify the right Cabinet Cooler System for you in a hurry too.  And since we keep them all in stock, we can get it to you in a hurry as well.

You can access our Cabinet Cooler Sizing Guide online, here.  You can fill in the blanks and submit it, or you can call in your data.  We do it over the phone all the time, and it only takes a minute.  Here’s what we’re going to ask for, and why:

NEMA 4 Cabinet Cooler
  • Enclosure dimensions.  We need the length, width, and height of your enclosure to calculate the heat transfer surface, and the volume of the enclosure.
  • Current Internal Air Temperature.  How hot is it inside your enclosure?  This is the starting point for figuring out the internal heat load…how much heat the components inside the box is generating.  This needs to be the air temperature – don’t use a heat gun, or you’re going to give me the surface temperature of something that may or may not be close to what I need.  Just put a thermometer in there for a few minutes.
  • Current External Air Temperature.  How hot is it in the area where the enclosure is located?  We’re going to compare this to the internal air temperature…the difference between the two is actually proportional to the heat load.  Also, if there’s anything cooling the enclosure right now (like circulating fans; more on those in a minute,) this reading is key to figuring out how much heat they’re removing.
  • Maximum External Air Temperature.  How hot does it get in the area on, say, the hottest day of summer?  We’ll need this to calculate the external heat load…how much heat the enclosure picks up from its surroundings.
  • Maximum Internal Temperature Desired.  Most electrical and electronic component manufacturers publish a maximum operating temperature of 104F (40C) – it’s kind of an “industry standard.”  Based on this, a lot of us in the enclosure cooling business set our products’ thermostats to 95F (35C) – if we’re maintaining the air temperature a decent amount cooler than the components are allowed to get, history and practice has shown that we’re going to provide more than adequate protection.  If your enclosure houses something with more sensitive temperature limitations, though, we can work with that too…that’s the only time you’re going to want to put something other than 95F (35C) in this field.
  • Cabinet Rating.  This is all about the environment…we offer three levels of protection, per NEMA standards:
    •  NEMA 12 – oil tight, dust tight, indoor duty.
    • NEMA 4 – oil tight, dust tight, splash resistant, indoor/outdoor duty.
    • NEMA 4X – oil tight, dust tight, splash resistant, corrosion resistant, indoor outdoor duty.

                     The NEMA rating does not affect the cooling capacity at all.

  • Other:  If the enclosure is mounted to the side of a machine, or a wall in the plant, you really don’t need to put anything here.  If it’s outside and exposed to direct sunlight, tell us what the surface finish (i.e., polished metal, painted grey, etc.) is so that we can account for solar loading too.  If anything else is unusual or peculiar about the application, let us know that too.
  • My Cabinet Is…Not Vented, Vented, Wall Mounted, Free Standing, Fan(s).  We’ll use what you tell us here to verify heat transfer surface (a wall mounted cabinet’s back surface isn’t a radiating surface, for example.)  Also, I mentioned fan cooling before, so without further ado…
  • Fan diameter or SCFM.  If there are fans circulating air into (and/or out of) the enclosure, they’re providing a finite amount of cooling right now.  Proper installation of a Cabinet Cooler System is going to require their removal.  Running a Cabinet Cooler System on a vented enclosure is just like running your air conditioner with the windows open.  So, if we know the size (or the SCFM…sometimes there’s a label on those fans, and we LOVE those folks who do that) then we can use that, and the temperatures you gave us above, to take the fan cooling into account.

Once we have all this information, it’s down to the math. Like I said, we do this all the time (especially during “Cabinet Cooler Season”) – give me a call.  Your heat problem isn’t waiting; why should you?

Jordan Shouse
Application Engineer
Send me an email
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Like us on FacebookTwitter: @EXAIR_JS





Let’s Size A Cabinet Cooler System!

I can’t remember the last time I put an exclamation point in the title of my blog, but it was probably the last time I got to talk about doing math. Or write about heat transfer.  Insert your favorite engineer joke here…I’m sure I have it coming.

We’re in the dog days of summer (in the Northern Hemisphere) for sure…or, as we call it, “Cabinet Cooler Season.”  If you’re having heat related problems with a control panel, give us a call; we can help.  If you’d like to know what we’re going to talk about, read on.

Heat can cause real problems for electrical and electronic components, in a hurry…we all know that.  Fortunately, we can also specify the right Cabinet Cooler System for you in a hurry too.  And since we keep them all in stock, we can get it to you in a hurry as well.

You can access our Cabinet Cooler Sizing Guide online, here.  You can fill in the blanks and submit it, or you can call in your data.  We do it over the phone all the time, and it only takes a minute.  Here’s what we’re going to ask for, and why:

Enclosure dimensions.  We need the length, width, and height of your enclosure to calculate the heat transfer surface, and the volume of the enclosure.

Current Internal Air Temperature.  How hot is it inside your enclosure?  This is the starting point for figuring out the internal heat load…how much heat the components inside the box is generating.  This needs to be the air temperature – don’t use a heat gun, or you’re going to give me the surface temperature of something that may or may not be close to what I need.  Just put a thermometer in there for a few minutes.

Current External Air Temperature.  How hot is it in the area where the enclosure is located?  We’re going to compare this to the internal air temperature…the difference between the two is actually proportional to the heat load.  Also, if there’s anything cooling the enclosure right now (like circulating fans; more on those in a minute,) this reading is key to figuring out how much heat they’re removing.

Maximum External Air Temperature.  How hot does it get in the area on, say, the hottest day of summer?  We’ll need this to calculate the external heat load…how much heat the enclosure picks up from its surroundings.

Maximum Internal Temperature Desired.  Most electrical and electronic component manufacturers publish a maximum operating temperature of 104F (40C) – it’s kind of an “industry standard.”  Based on this, a lot of us in the enclosure cooling business set our products’ thermostats to 95F (35C) – if we’re maintaining the air temperature a decent amount cooler than the components are allowed to get, history and practice has shown that we’re going to provide more than adequate protection.  If your enclosure houses something with more sensitive temperature limitations, though, we can work with that too…that’s the only time you’re going to want to put something other than 95F (35C) in this field.

Cabinet Rating.  This is all about the environment…we offer three levels of protection, per NEMA standards:

NEMA 12 – oil tight, dust tight, indoor duty.

NEMA 4 – oil tight, dust tight, splash resistant, indoor/outdoor duty.

NEMA 4X – oil tight, dust tight, splash resistant, corrosion resistant, indoor outdoor duty.

The NEMA rating does not affect the cooling capacity at all.

Other:  If the enclosure is mounted to the side of a machine, or a wall in the plant, you really don’t need to put anything here.  If it’s outside and exposed to direct sunlight, tell us what the surface finish (i.e., polished metal, painted grey, etc.) is so that we can account for solar loading too.  If anything else is unusual or peculiar about the application, let us know that too.

My Cabinet Is…Not Vented, Vented, Wall Mounted, Free Standing, Fan(s).  We’ll use what you tell us here to verify heat transfer surface (a wall mounted cabinet’s back surface isn’t a radiative surface, for example.)  Also, I mentioned fan cooling before, so without further ado…

Fan diameter or SCFM.  If there are fans circulating air into (and/or out of) the enclosure, they’re providing a finite amount of cooling right now.  Proper installation of a Cabinet Cooler System is going to require their removal.  Running a Cabinet Cooler System on a vented enclosure is just like running your air conditioner with the windows open.  So, if we know the size (or the SCFM…sometimes there’s a label on those fans, and we LOVE those folks who do that) then we can use that, and the temperatures you gave us above, to take the fan cooling into account.

Once we have all this information, it’s down to the math. Like I said, we do this all the time (especially during “Cabinet Cooler Season”) – give me a call.  Your heat problem isn’t waiting; why should you?

Before I go…here’s a nice little video, walking you through the Cabinet Cooler Sizing Guide.  Yes, I just made you read the book before watching the movie…feel free to tell me which one you liked better.

Russ Bowman
Application Engineer
EXAIR Corporation
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EXAIR Cabinet Coolers are Ideal for Keeping Electronics Cool

Here in Southwest Ohio, high temperatures have consistently been in the low-to-mid 90s for the last couple weeks. Temperatures that high mean it’s time to stay inside and crank up the A/C or head to the nearest swimming pool.

For the electronic control panels in your facility you’ll want to take a different approach. Traditional refrigerant-based air conditioners for electronic panels can be installed, but they’ll require long installation periods, maintenance and higher purchase prices. Refrigerant-based systems must be constantly monitored to replace filters, clean condensers, and checking the compressors to prevent any failure. As for tossing your control panel into a swimming pool to cool off, well I’ll let you be the judge of why that’s a bad idea 😉.

DualCCETC
EXAIR’s Dual Cabinet Cooler With Electronic Temperature Controller

The best solution for keeping your electronics cool is an EXAIR Cabinet Cooler. With nothing more than a supply of compressed air to operate, the Cabinet Cooler installs in minutes through a standard electrical knockout. It has no moving parts to wear out, and when supplied with filtered compressed air the Cabinet Cooler requires absolutely NO maintenance. For higher temperature applications in extreme ambient conditions, we also have High Temperature Cabinet Coolers available.

Just last month we hosted a Webinar discussing Cabinet Coolers as the Intelligent Solution for Compressed Air Cooling. If you happened to miss it, you’re not too late!! Click here for a replay of the Webinar on the EXAIR website.

webinar-on-demand

To  which size Cabinet Cooler is right for you, complete the Cabinet Cooler Sizing Guide online. One of the EXAIR Application Engineers will then be able to determine the cooling capacity required based on the conditions of your cabinet. In less than 24 hours, you’ll have a response from us with the recommended model. With all Cabinet Cooler Systems available from stock, you can get one shipped out to you right away!

CCSizingGuide2016
You can submit your data via email or fax, or you can call an EXAIR Application Engineer for immediate assistance.

IF you need a faster turn-around than that – call us or chat online and we will get the process started immediately. These products are in stock and ready to ship same day to solve your problem. Don’t wait until it’s too late, EXAIR’s Cabinet Cooler is THE solution for maintaining the temperature inside of your electronic enclosures.

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