EXAIR Cabinet Cooler Systems: Thermostats and Accessories

For most industrial enclosure cooling applications, a temperature of 95°F (35°C) is sufficient to be below the rated maximum operating temperature of the electrical components inside the cabinet. So, it is important to turn the cabinet cooler system on to keep the components cool, but at the same time we all know compressed air can be expensive if you over use it. A thermostat allows you to turn the cooler off when the enclosure is at or below the desired temperature, saving compressed air over continuous operation.

Cabinet Cooler

Here at EXAIR we are all about Engineered Solutions that will not only save you money but help your company “Go Green” by drastically lowering your energy costs. And when it comes to Cabinet Coolers, we have several options to control and manage the compressed air supply.

The most popular option is our Thermostat Control. EXAIR thermostats feature a bimetallic contact strip to open and close the electrical circuit in response to air temperatures.  These thermostats quickly respond to changes in air temperature and are specifically suited for their intended use.  Preset for 95°F (35°C), a suitable temperature for most electronic devices, these thermostats are fully adjustable for specific application needs. When thermostat closes it then turns the solenoid valve off turning the compressed air supply off. These thermostats are available in 12VAC, 240VAC and 24VDC.

Thermostat and ETC

In the event a more sophisticated thermostat control is needed, Electronic Temperature Control units can be implemented.  These standalone units utilize a thermocouple to determine internal cabinet temperatures which display onto a digital readout.  Push-button controls on the digital readout board allow for easy modification of the internal cabinet temperature set-point.  When the desired internal temperature is reached, the Cabinet Cooler system will turn off automatically.

One accessory that will give the flexibility to install EXAIRS cabinet cooler system is our Side Mount Kit. Sometimes there isn’t room above an electrical panel to fit the Cabinet Cooler, even though it takes just 5″ to 7.25″ of space above. In these cases, the Side Mount Kit is available to handle any of the Cabinet Cooler sizes and NEMA ratings. The NEMA 4 and 4X Cabinet Coolers must be mounted vertically for the unit to properly resist the ingress of liquids and maintain the integrity of the cabinet NEMA rating.

EXAIR NEMA 12 Cabinet Cooler System w/ Side Mount Kit
NEMA 12 Cooler with Side Mount Kit

The Side Mount Kits install into a standard electrical knockout (1-1/2 NPS) for easy installation.

If you’re in need of a suitable cooling solution for an industrial enclosure, consider an EXAIR Cabinet Cooler systems.  They’re smaller than traditional AC units, faster to install, and require little-to-no-maintenance.  Feel free to contact an EXAIR Application Engineer with any questions, or fill out our online Cabinet Cooler Sizing Guide to have an Application Engineer contact you.

Jordan Shouse
Application Engineer
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EXAIR Cabinet Coolers vs. Air to Air Heat Exchangers

At EXAIR we’ve been providing enclosure cooling solutions for decades, and in many cases those cooling solutions have remained in place for decades as well.  In the time we’ve been in the market with industrial enclosure cooling solutions we’ve encountered a number of alternative means for enclosure cooling.  One of those methods is an air-to-air heat exchanger.

heat exchanger 1
Heat exchanger

An air-to-air heat exchanger uses the temperature differential between the ambient air surrounding an enclosure and the hot air inside an enclosure to create a cooling effect.  A closed loop system exchanges the heat inside the enclosure with the outside air in an effort to maintain a set internal temperature.  The heat exchange of most air-to-air unit relies on a heat pipe, a heat-transfer device which converts an internal refrigerant liquid into vapor by placing one end of the pipe in contact with the hot environment.  The heated vapor travels to the other end of the pipe which is in contact with a cooler environment.  The vapor condenses back into a liquid (releasing latent heat) and returning to the hot end of the pipe and the cycle repeats.

But, this type of a solution does give some cause for concern, especially when considering their use in an industrial environment.  Here are the key points to keep in mind when comparing an air-to-air cooler to an EXAIR Cabinet Cooler.

Cabinet Cooler Family
EXAIR Cabinet Coolers

Required temperature differential based on ambient air temp

An air-to-air heat exchange relies on the ΔT between the ambient air temperature and the internal enclosure air temperature to produce cooling.  If this ΔT is low, or the ambient temperature rises, cooling is diminished.  This means that as the temperatures in your facility begin to rise, air-to-air heat exchangers become less and less effective.  Larger air-to-air heat exchangers can be used, but these may be even larger than the enclosure itself.

EXAIR Cabinet Coolers rely on the ΔT between the cold air temperature from the Cabinet Cooler (normally ~20°F) and the desired internal enclosure temperature (normally 95°F).  The cold air temperature from the Cabinet Cooler is unaffected by increases in ambient temperatures.  The large ΔT and high volume cold air flow produced by a Cabinet Cooler results in more cooling capacity.  And, we can increase cooling capacity from a Cabinet Cooler without increasing its physical footprint, which is already much, much smaller than an air-to-air type of unit.

 

Cooling in high temperature environments

Due to their nature of operation, an air-to-air heat exchanger must have an ambient temperature which is lower than the desired internal temperature of the enclosure.  If the ambient air has a higher temperature, air-to-air units provide zero cooling.

Cabinet Coolers, on the other hand, can be used in hot, high temperature environments up to 200°F (93°C).

EXAIR's High Temp Cabinet Cooler Systems
High temperature Cabinet Coolers

 

Cooling in dirty environments

Dirt in the ambient environment will impact cooling performance with an air-to-air heat exchanger.  In order for the air-to-air unit to effectively remove heat, the heat pipe must have access to ambient air.  With any exposure to the ambient environment comes the possibility for the ambient end of the heat pipe to become covered in ambient contaminants such as dust.  This dust will create an insulation barrier between the heat pipe and the ambient air, decreasing the ability for the heat pipe to condense the vapors within.  Because of this, most air-to-air devices use filters to separate the heat pipe from the ambient environment.  But, when these filters become clogged, access to ambient temperatures are reduced, and cooling capacity of the air-to-air unit reduces as well.

Cabinet Coolers have no problem operating in dirty environments.  In fact, it is one of their strengths.  Without any moving parts to wear out or any need to contact ambient air for cooling purposes, a dirty environment poses no problems.  In fact, check out this blog post (and this one) about EXAIR Cabinet Coolers operating maintenance free for years in dirty environments.

exair-cabinet-cooler-03-2002-2008
NEMA 12 Cabinet Cooler in a Dirty Environment

Size and time required to install

Air-to-air heat exchangers vary in size, but even the smallest units can have large dimensions.  Many applications have limited space on the enclosure, and a large, bulky solution can be prohibitive.  Couple this with the time and modification required to the enclosure to install a large air-to-air unit, and the “solution” may end up bringing additional problems.

Another key aspect of the Cabinet Cooler is its size.  Small, compact, and easy to mount on the top or side of an enclosure, Cabinet Coolers install in minutes to remove overheating problems.

 

Heat within an electrical cabinet can be a major issue for manufacturing companies. The costs associated with down time and repairs on sensitive electronics that fail due to heat or environmental contaminants, are an unnecessary burden. If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.

Jordan Shouse
Application Engineer
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6 Primary Benefits of Cabinet Coolers (Vortex Tube Enclosure Coolers)

First off, I want to dispel any notion that there might be something that’s NOT great about EXAIR Cabinet Cooler Systems.  Are there other methods to provide effective cooling to an electrical panel?  Of course there are, and frankly, if one particular method was clearly superior in any & every situation, the makers of that one would have put all the others out of business by now.  But for now, let’s consider:

1. Simplicity: Cabinet Cooler Systems need compressed air to work.  That’s it.  Supply them with clean, moisture free air, and they’ll run darn near indefinitely, maintenance free. What could be easier?

2. Control:  Continuous Operation systems have their place (more on that in a minute,) but in most cases, Thermostat Control is preferred, for a couple of reasons:

  • Most electrical and electronic components have a rated maximum operating temperature of 104°F (40°C).  Maintaining the air temperature at a reasonable level less than that is all you need…any lower, and you’re just wasting energy, no matter what method of cooling you use.  Our Thermostats are preset at 95°F (35°C) to ensure heat protection, while limiting operating costs.
  • There is such as thing as “too cold.” Particularly sensitive instrumentation & controls may exhibit varied behavior at different temperatures.
  • Our bimetallic probe-type thermostats are ideal for controlling air temperature.  They have much faster response time than other mechanical styles, meaning the system won’t keep running once it’s cool enough, and it starts running as soon as it starts getting too hot.  They’re also easy to reset, if the preset of 95°F (35°C) is not suitable for particular specific needs.
  • If constant monitoring, or frequent changes in control temperature are desired, the ETC Electronic Temperature Control offers these benefits, via a quick response thermocouple and pushbutton operation.

3. Environmental concerns: No matter where a panel is located in your plant, and what it might be exposed to, EXAIR Cabinet Cooler Systems will keep the environment out of that panel:

  • NEMA 12 Cabinet Cooler Systems are oil tight, dust tight, and rated for indoor duty.
  • NEMA 4 systems provide the same protection as NEMA 12, and are additionally splash resistant, and are rated for indoor/outdoor duty.
  • NEMA 4x systems offer NEMA 4 protection, and are made of stainless steel for corrosion resistance.
  • HazLoc Cabinet Coolers are UL Classified & CE Compliant.

    HazLoc Cabinet Cooler Systems also maintain NEMA 4 or 4X integrity, and are for use with classified enclosure purge & pressurization systems in hazardous locations:

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

4. Dependable protection: In most cases, the less moving parts something has, the more reliable it is.  With NO moving parts, EXAIR Cabinet Cooler Systems absolutely prove this out:

  • Unlike refrigerant-based systems, there are no filters to clean, no coils to foul or corrode, and no electric motors to burn out.
  • No potential contaminants from outside air ever enter the enclosure…all the cold air comes from your compressed air supply, through an Automatic Drain Filter Separator fitted with a 5 micron particulate element and a centrifugal separator for moisture removal.

5. Selection:  Cooling capacities range from 275 Btu/hr to 5,600 Btu/hr, and they’re all in stock, ready for immediate shipment.

6. Special considerations:  “Customized” usually means high prices and long lead times. Not so for a number of EXAIR Cabinet Cooler System options:

  • This NEMA 4 Dual Cabinet Cooler System protects a critical equipment panel on a hot roll steel line.

    High Temperature systems are available from stock, for installation in areas where the ambient temperature can exceed 125°F (52°C,) all the way up to 200°F (93°C.)

  • Continuous Operation Systems aren’t the only way to constantly keep environmental contaminants out…Non-Hazardous Purge (NHP) systems combine the efficiency of Thermostat Control by always passing a small amount of air flow, to provide a slight positive pressure, even when the temperature is lower than the Thermostat set point.  This way, the Cabinet Cooler System only operates to maintain appropriate cooling, but the panel is still protected all the time.
  • When additional protection from harsh and corrosive environments is needed, or when specified by strict facility requirements (I’m looking at you, Food, Pharma, and Nuclear Plants,) our NEMA 4X Cabinet Cooler Systems can be provided in Type 316 Stainless Steel construction, from stock.

6.5 Simplicity, part 2:  Not only are they simple to operate…

  • They install, in minutes, through a standard knockout in the top of your enclosure.

    Side Mount Kits maintain NEMA 4/4X Splash Resistance.
  • If there’s no room on top, or if it’s just more practical, you can put them on the side of the panel using a Side Mount Kit.
  • Don’t know which one to pick, or need help determining your heat load?  Then use our Cabinet Cooler System Sizing Guide.  There’s one in the catalog that you can fill out and fax or email to us, or you can find it on our website under the “Features” tab on any Cabinet Cooler product page…just fill in the blanks and click “Submit.”  Or, you can always simply call in the data to an Application Engineer.  We can calculate your heat load in just a minute or so, and we do it over the phone all the time.

If you’d like to find out more about heat protection for your electrical or electronic panels, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Opening Day in Cincinnati Means Summer is Fast Approaching!

The first day of spring “officially” started on March 20th this year. I place the word officially in quotations as I don’t recognize spring until I can come home from work, flip on the TV and watch a Cincinnati Reds game. THAT is when spring starts in my mind, yesterday was that day. If you’re from Cincinnati, I don’t need to tell you how important Opening Day is here. As home to the first professional Major League Baseball team, we take great pride in our Cincinnati Reds here. Despite the recent spat of losing seasons…. So much so that Red’s Opening Day has become a de facto holiday of sorts. In fact, many schools will even recognize an excused absence for students that take the day off to go down for the game and festivities prior to the first pitch. There’s even a parade!!

reds great american
view of GABP from center field

With spring upon us, that means summer is right around the corner. While this is an exciting event for most of us, your maintenance manager may beg to differ. Increased temperatures lead to heat related problems in your electrical panels. With summer coming along before you know it, the time is now to get a solution in place before it becomes an issue.

CC_Actionshot

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.

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, contact an Application Engineer today and we’ll see to it that this summer your cabinets remain cool!

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

 

Great American Ballpark image courtesy of ChipMahaney via Creative Commons License

Cabinet Cooling with Thermostat Control and ETC

An EXAIR Cabinet Cooler® System with either the Thermostat Control or the Electronic Temperature Control (ETC) option includes a temperature measuring device that is used to control the operation of the Cabinet Cooler System to maintain the set-point temperature.Thermostat and ETC

For most industrial enclosure cooling applications, a temperature of 95°F (35°C) is sufficient to be below the rated maximum operating temperature of the electrical components inside the cabinet. EXAIR Thermostats are preset to 95°F (35°C) and are adjustable. Maintaining the cabinet at 95°F (35°C) will keep the electronics cool and provide long life and reduced failures due to excessive heat. But if 95°F (35°C) is good, why not cool the cabinet to 70°F (21.1°C)?

When cooling an enclosure to a lower temperature, two things come into play that need to be considered. First, the amount of external heat load (the heat load caused by the environment) is increased. Using the table below, we can see the effect of cooling a cabinet to the lower temperature. For a 48″ x 36″ x 18″ cabinet, the surface area is 45 ft² (4.18 m²). If the ambient temperature is 105°F (40.55°C), we can find from the table the factors of 3.3 BTU/hr/ft² and 13.8 BTU/hr/ft² for the Temperature Differentials of 10°F (5.55°C) and 35°F (19.45°C). The factor is multiplied by the cabinet surface area to get the external heat load. The heat load values calculate to be 148.5 BTU/hr and 621 BTU/hr, a difference of 472.5 BTU/hr (119.1 kcal/hr)

External Heat Load

The extra external heat load of 472.5 BTU/hr (119.1 kcal/hr) will require the Cabinet Cooler System to run more often and for a longer duration to effectively remove the additional heat. This will increase, unnecessarily, the operating costs of the cooling operation.

The other factor that must be considered when cooling an enclosure to a lower temperature is that the Cabinet Cooler cooling capacity rating is effected. I won’t go into the detail in this blog, but note that a 1,000 BTU/hr Cabinet Cooler (rated for 95°F (35°C cooling) working to cool a cabinet down to 70°F (21.1°C) instead of 95°, has a reduced cooling capacity of 695 BTU/hr (174 kcal/hr).  The reduction is due to the cold air being able to absorb less heat as the air rises in temperature to 70°F instead of 95°F.

In summary – operating a Cabinet Cooler System at 95°F (35°C) provides a level cooling that will keep sensitive electronics cool and trouble-free, while using the least amount of compressed air possible.  Cooling to below this level will result in higher operation costs.

If you have questions about Cabinet Cooler Systems or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Explanation of Hazardous Locations – Class II Div. 1, Groups E, F and G

Per the National Electrical Code (NEC) there are (3) classifications for areas that are defined as hazardous.  They are Class I (gases & vapors), Class II (flammable dusts) & Class III (fibers), the focus of today’s Blog is on Class II locations.

Class II locations are those that are hazardous because of the presence of combustible dust. Note that the dust must be present in sufficient quantities for a fire or explosion hazard to exist. The fact that there is some combustible dust present does not mean a Class II hazardous location exists. Dust is defined as a combustible material that must exist as a finely divided solid of 420 microns (0.420 mm) or less. This will allow the dust to pass through a No. 40 sieve.  Just as in Class I, Division 1 and 2, the subdivision of Class II into Divisions 1 and 2 identifies the likelihood that there is an explosion hazard.

Division 1 locations are defined as an area where the amount of combustible dust is either suspended in the air or accumulated on surfaces in a sufficient concentration to allow for ignition.  The ignition could be caused by a failure or malfunction of the equipment in the classified area.  Group E & F dust (see chart below) are considered conductive and could penetrate into electrical equipment such as electric motors, control panels, electrical panels, etc.. and cause an electrical failure.

Chart1

Group E dusts are metal dusts, such as aluminum and magnesium. In addition to being highly abrasive, and likely to cause overheating of motor bearings if it gets into them. Group E dusts are also electrically conductive and if they are allowed to enter an enclosure can cause an electrical failure.

Chart2

Group F dusts are carbonaceous, the primary dust in this group is coal dust. Coal dust has a lower ignition temperatures than those in Group E.  While Group F dust has a higher thermal insulating value than the layer of Group E.  Therefore Group F requires more control of the temperature on the surfaces that the dust settles on. Group E dusts are semi-conductive, however if the voltages are 600 volts or less it is not generally considered a factor.

Chart3

Group G dusts include plastic dusts, most chemical dusts and food-grain dusts. They are not electrically conductive. Generally these dusts have the highest thermal insulating characteristics and the lowest ignition temperatures. Therefore the equipment used in Group G areas must have the lowest surface temperatures to prevent ignition of a layer.

Chart4

Lastly, equipment rated for use in Classified Environments have a rating called the Temperature Code or “T-Code”.  This is the temperature or temperature range that the rated device will operate normally and/or in a failed or failing state.  Consider something as common as a light fixture, electric motors, etc.. as they could become hot enough to cause ignition depending on the type of dust in the area.  So be sure to check the “T-Codes” for every piece of equipment that will be used within a Classified Environments.

Chart5

When you are looking for expert advice on Hazardous Location Cabinet Coolers or safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Steve Harrison
Application Engineer
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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
Email: johnball@exair.com
Twitter: @EXAIR_jb