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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Hazardous Location Cabinet Coolers

Last year was a big year for EXAIR’s Cabinet Cooling product line, in November  we launched our first Hazardous Location Cabinet CoolersEXAIR has always been a leading supplier in compressed air-based Cabinet Coolers, now we have expanded on that to work in the most high-risk conditions.

When a Hazardous Location Cabinet Cooler is used in conjunction with a purge system, they will keep electrical equipment at the desired operating temperature to protect and lengthen the lifetime of pricey controls and power supplies.

hazloc_illLsr-800w
Hazardous Location Cabinet Cooler

 

Electrical equipment can cause explosions in certain atmospheres. Equipment used in areas where explosive concentrations of dusts or vapors may exist must be equipped with special wiring and other electrical components for safety purposes. Hazardous (classified) locations such as these might exist in aircraft hangars, gasoline stations, paint-finishing locations or grain bins. EXAIR’s Hazardous Location Cabinet Coolers have been approved and tested by UL for use in the following areas:

classified_cULus_360x283
UL Approved and Tested

Class I Div 1&2 – Groups A, B, C, and D

  • Class I Areas refer to the presence of flammable gases or vapors in quantities sufficient to produce explosive or ignitable mixtures. Class I Div 1 will have ignitable concentrations of flammable gases present during the course of normal operations. This is level of approval is one that differentiates the EXAIR Hazardous Location Cabinet Coolers from much of the competition. Class 1 Div 2 areas will have flammable gasses or vapors present only in the event of an accident or during unusual operating conditions.

Class II Div 1&2 – Groups E, F, and G

  • Class II areas are locations in which combustible dust may exist. The end user shall avoid installation of the device in a Class II environment where dust may be readily disturbed from the exhausts of the Hazardous Location Cabinet Cooler. Any dust formed in the vicinity of the cooler must be cleaned regularly.

Class III

  • Class III areas are locations that will have ignitable fibers or flyings present. This is common within the textile industry.

The Cabinet Cooler also carries a temperature rating of T3C, meaning it cannot be installed near any materials that could auto-ignite at temperatures in excess of 320°F.

The Hazardous Location Cabinet Cooler is available in (8) different cooling capacities ranging from 1,000 Btu/hr – 5,600 Btu/hr. The Cabinet Cooler is the best solution for protecting your sensitive electronics from heat, dirt, and moisture. With Nema 4/4X systems available, the Hazardous Location Cabinet Coolers will keep the cabinet cool without compromising the integrity of the enclosure.

If you’ve got an electrical cabinet installed within a hazardous location, fill out the Cabinet Cooler Sizing Guide and allow an EXAIR Application Engineer to determine the most suitable model for you.

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

316 Stainless Steel Products- Always in Stock

Metallurgically speaking, stainless steel is a steel alloy with the highest percentage contents of iron, chromium and nickel, with a minimum of 10.5% chromium content by mass, and a maximum of 1.2% of carbon by mass.

Stainless steels are widely regarded for the corrosion resistance that they exhibit. As the chromium content is raised, the corrosion resistance increases as well. The addition of molybdenum also increases the corrosion resistance to reducing acids and against pitting attacks in chloride solutions. By varying the chromium and molybdenum content, different grades of stainless steel are produced with each suited for varying environments. Due to the resistance to corrosion and staining, stainless steel is ideal material for many applications, especially in the food, pharmaceutical, and chemical industries.

The 300 series stainless steels are considered chromium-nickel alloys and is the largest group and most commonly used. Of the different compositions within the 300 series family, Type 304 stainless is the most widely used followed by Type 316, which has 2% molybdenum added to provide greater resistance to acids and to localized corrosion caused by chloride ions.

Table below shows the nominal composition by mass content for 316 stainless steel

316 SS Table

Because 316 stainless steel provides a high level of corrosion resistance, resists pitting, and has good strength properties, EXAIR manufactures many of its products from 316 stainless steel material so that they can be used in the harshest of environments.

Of the EXAIR products these are available off the shelf in 316 stainless steel- Super Air Knife, certain sizes of Adjustable Air Amplifiers, numerous Air Nozzles, Line Vacs including the Sanitary Flanged style, NEMA Type 4X and Hazardous Location Cabinet Coolers. If you need one of our other products such as the Super Air Wipes or Vortex Tubes made in 316 stainless steel, just let us know. Of course we also have them made from Type 303 stainless steel, in stock and ready for shipment (and aluminum, too!)

gh_stainless-steel-super-air-knife-750x696.jpg
316 Stainless Steel Super Air Knife

And, you don’t have to wait months or even weeks, as we keep all of these in stock, ready for shipment.

If you have questions about 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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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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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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