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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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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Choosing the Right Vortex Tube – Max Refrigeration vs. Max Cold Temperature

The Vortex Tube is a low cost, reliable, maintenance free way to provide cooling to a wide variety of industrial spot cooling problems.

VT_air2

There are two (2) popular uses for the Vortex Tubes.  One is to spot cool a warm item as fast as possible.  The other is to chill an item to as low a temperature as possible. Because these are very different requirements, different Vortex Tube configurations exist to handle each.

For those applications of spot cooling, we recommend the 3200 series of Vortex Tubes. They are designed to be most efficient at providing maximum refrigeration, which is a function of high cold air flow rate and moderate temperature differential of the cold air to the warm item.

And for those applications of chilling an item to a very low temperature at low flow rate , we recommend the 3400 series of Vortex Tubes.  They are designed to be most efficient at providing maximum cold air temperatures, but with a lower cold air flow rate.

An important parameter for the Vortex Tubes is the Cold Fraction.  By adjusting the hot valve on a vortex tube, the amount of air that is discharged through the cold end changes. When expressed as a percentage of the total compressed air that is supplied to the vortex tube, we get the Cold Fraction.  For example, if the hot valve is adjusted so that for every 10 parts of compressed air supplied, we get 7 parts of cold air, then we have a 70% Cold Fraction. When you know the Cold fraction setting and the compressed air supply pressure, you can use the Vortex Tube Performance tables and get the cold air discharge temperature.

Using the table below left, at 100 PSIG compressed air pressure and a 70% Cold Fraction, we can expect the cold air discharge temperature drop to be 71°F.  With 70 ° compressed air temperature, the cold air will be at -1°F.

Vortex Tube Charts
Vortex Tube Performance Tables

The 3200 series of Vortex Tubes are for use in the 50-80% Cold Fraction range, and the model 3400 series is designed for use in the 20-50% Cold Fraction ranges, to maximize the performance of each.

In summary, the selection of the Vortex Tube that best meets the application needs is based on the desired cold air flow rate, and the temperature of air desired. Once these are known, using the tables can provide the information needed to select the best option.

For those applications where we are unsure what will work best, we offer the EXAIR Cooling Kits, that include a Vortex Tube (small, medium, or large) and an array of Generators, to allow the configuration of the full range of Vortex Tubes within each size family.

  • Model 3908 – Small Vortex Tube Cooling Kit – build models 3202, 3204, 3208, and 3402, 3404, 3408
  • Model 3930 – Medium Vortex Tube Cooling Kit – build models 3210, 3215, 3225, 3230, 3240, and 3410, 3415, 3425, 3430, 3440
  • Model 3998 – Large Vortex Tube Cooling Kit – build models 3250, 3275, 3298, 3299, and models 3450, 3475, 3498, 3499

3930

If you have questions about Vortex Tubes or any of the 16 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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The Adjustable Spot Cooler – Cold Air to -30°F (-34°C) From Your Compressed Air Supply

The Adjustable Spot Cooler is a low cost, reliable , maintenance free way to provide spot cooling to a myriad of industrial applications. Simply turn the knob, and the temperature can be changed to suit the needs of the process. The Adjustable Spot Cooler delivers precise temperature settings from -30°F (-34°C) to room temperature.

Adjustable Spot Cooler
Adjustable Spot Cooler

The Adjustable Spot Cooler utilizes the Vortex Tube technology that converts compressed air into a cold air stream. To learn more about EXAIR vortex tubes, click here.

  • It can produce temperatures form -30°F to +70°F (-34°C tp +21°C)
  • Parts included for flow rates of 15, 25 and 30 SCFM (425, 708, 850 SLPM.) The unit comes from the factory set at 25 SCFM (708 SLPM)
  • It can produce refrigeration up to 2,000 BTU/hr (504 Kcal/hr.)

A swivel magnetic base allows for easy mounting and portability, you can move it from machine to machine as needed. The flexible cold air outlet tubing holds its position and is easy to aim. Most importantly, there are no moving parts or CFC’s, ensuring maintenance free operation.

asc_onlathecmyk
The Adjustable Spot Cooler maintains critical tolerances on machined plastic parts

How the Adjustable Spot Cooler WorksThe Adjustable Spot Cooler incorporates a vortex tube to convert a supply of compressed air (1) into two low pressure streams, one hot and one cold. With the turn of a knob, the temperature control valve (2) allows some hot air to flow through a muffling sleeve and out the hot air exhaust (3). The opposite end provides a cold air stream (4) that is muffled and discharged through the flexible hose, which directs it to the point of use. The swivel magnetic base (5) provides easy mounting and portability.


The Adjustable Spot Cooler can produce a wide range of air flows and temperatures as determined by the temperature control valve knob setting and the generator installed. The generator controls the total SCFM (SLPM) of compressed air consumption, and is easy to change. From the factory, the 25 SCFM (708 SLPM) generator is installed, producing up to 1,700 BTU/hr (429 Kcal/hr) of cooling. For less cooling, the 15 SCFM (425 SLPM) generator can be installed, providing up to 1,000 BTU/hr (252 Kcal/hr) of cooling. And for more cooling, the 30 SCFM (850 SLPM) generator can be installed, providing up to 2,000 BTU/hr (504 Kcal/hr) of cooling.

Adjustable Spot Cooler Specifications

Two (2) Systems are available as shown below, and include the 15 and 30 SCFM (425 and 850 SLPM) generators, a filter separator, and either a single or dual point hose kit.

Adjustable Spot Cooler Systems3825_3925 adj spot cooler

If you have questions about the Adjustable Spot Cooler or any of the 16 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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What’s In My Air, And Why Is It Important?

Everyone knows there’s oxygen in our air – if there wasn’t oxygen in the air you’re breathing right now, reading this blog would be the least of your concerns. Most people know that oxygen, in fact, makes up about 20% of the earth’s atmosphere at sea level, and that almost all the rest is nitrogen. There’s an impressive list of other gases in the air we breathe, but what’s more impressive (to me, anyway) is the technology behind the instrumentation needed to measure some of these values:

Reference: CRC Handbook of Chemistry and Physics, edited by David R. Lide, 1997.

We can consider, for practical purposes, that air is made up of five gases: nitrogen, oxygen, argon, carbon dioxide, and water vapor (more on that in a minute.)  The other gases are so low in concentration that there is over 10 times as much carbon dioxide as all the others below it, combined.

About the water vapor: because it’s a variable, this table omits it, water vapor generally makes up 1-3% of atmospheric air, by volume, and can be as high as 5%.  Which means that, even on a ‘dry’ day, it pushes argon out of the #3 slot.

There are numerous reasons why the volumetric concentrations of these gases are important.  If oxygen level drops in the air we’re breathing, human activity is impaired.  Exhaustion without physical exertion will occur at 12-15%.  Your lips turn blue at 10%.  Exposure to oxygen levels of 8% or below are fatal within minutes.

Likewise, too much of other gases can be bad.  Carbon monoxide, for example, is a lethal poison.  It’ll kill you at concentrations as low as 0.04%…about the normal amount of carbon dioxide in the atmosphere.

For the purposes of this blog, and how the makeup of our air is important to the function of EXAIR Intelligent Compressed Air Products, we’re going to stick with the top three: nitrogen, oxygen, and water vapor.

Any of our products are capable of discharging a fluid, but they’re specifically designed for use with compressed air – in basic grade school science terms, they convert the potential energy of air under compression into kinetic energy in such a way as to entrain a large amount of air from the surrounding environment.  This is important to consider for a couple of reasons:

  • Anything that’s in your compressed air supply is going to get on the part you’re blowing off with that Super Air Nozzle, the material you’re conveying with that Line Vac, or the electronics you’re cooling with that Cabinet Cooler System.  That includes water…which can condense from the water vapor at several points along the way from your compressor’s intake, through its filtration and drying systems, to the discharge from the product itself.
  • Sometimes, a user is interested in blowing a purge gas (commonly nitrogen or argon) –  but unless it’s in a isolated environment (like a closed chamber) purged with the same gas, most of the developed flow will simply be room air.

Another consideration of air make up involves EXAIR Gen4 Static Eliminators.  They work on the Corona discharge principle: a high voltage is applied to a sharp point, and any gas in the vicinity of that point is subject to ionization – loss or gain of electrons in their molecules’ outer valences, resulting in a charged particle.  The charge is positive if they lose an electron, and negative if they gain one.  Of the two gases that make up almost all of our air, oxygen has the lowest ionization energy in its outer valence, making it the easier of the two to ionize.  You can certainly supply a Gen4 Static Eliminator with pure nitrogen if you wish, but the static dissipation rate may be hampered to a finite (although probably very small) degree.

At EXAIR Corporation, we want to be the ones you think of when you think of compressed air.  If you’ve got questions about it, give us a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Air photo courtesy of Bruno Creative Commons License

The Case for the Cold Gun

Heat is an unavoidable by-product of any cutting or machining operation. Think about it: you’re creating friction on a piece of material with a fast-moving piece of harder material in order to forcibly separate pieces of the original material from its existing shape & size. No matter what, something’s going to get hot: the work piece, the tooling, or (almost always) both. If you don’t do something about it, your parts can become damaged, your tooling can become dull and brittle, and productivity will suffer.

There are ways to alleviate the problem…you can slow the speed of your tooling, but that’s hardly practical, and only marginally effective.  You can use liquid cooling…in fact, you may have to if the particulars of the operation require the lubrication you can only get from a cutting oil or liquid coolant.  But those can be messy, expensive, and the time you spend maintaining the coolant could certainly be spent better elsewhere…like, on machining your products!

The EXAIR Cold Gun Aircoolant System is a novel solution to these problems…heat related and otherwise:

  • The Cold Gun uses compressed air to produce a stream of clean, cold air at 50°F (28°C) below supply air temperature.
  • They use Vortex Tube technology…no moving parts to wear out.
Instant cold air flow with no moving parts!
  • Cold flow and temperature are preset to optimize cooling capability, and are non-adjustable to prevent freeze-up during use.
  • Eliminates the expense of both the purchase & disposal of cutting fluids.
  • Removes the potential for health problems associated with breathing mist & vapors, and the safety issue of slipping on a wet floor.

Cold Gun Aircoolant System selection is easy & straightforward…we offer a standard, and a High Power version to meet your specific needs.

Four systems to choose from, to meet most any need.

We also offer Single & Dual Point Hose Kits, to further meet the needs of your application.  Right now, you don’t have to decide up front…order a Cold Gun Aircoolant System with a Single Point Hose Kit before December 31, 2018, and we’ll throw in the Dual Point Hose Kit for free.

If you’d like to find out more about how Cold Gun Aircoolant Systems can improve your machining or cutting operations, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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The Theory of the Vortex Tube

There are many theories regarding the dynamics of a vortex tube and how it works. Many a graduate student has studied them as part of their research requirements.

VT_air2

The Vortex Tube was invented by accident in 1928, by George Ranque, a French physics student. He was performing experiments on on a vortex-type pump that he had developed and noticed that warm air exhausted from one end and cold air from the other! Ranque quickly stopped work on the pump, and started a company to take advantage of the commercial possibilities for this odd little device that produced both hot and cold air, using only compressed air, with no moving parts. The company was not successful, and the vortex tube was forgotten until 1945 when Rudolph Hilsch, a German physicist, published a widely read paper on the device.

A vortex tube uses compressed air as a power source, has no moving parts, and produces hot air from one end and cold air from the other. The volume and temperature of the two air streams is adjustable with a valve built into the hot air exhaust.  Temperatures as low as -50°F (-46°C) and as high as 260°F (127°C) are possible.

Here is one widely accepted explanation of the physics and the phenomenon of the vortex tube.VT

Compressed air is supplied to vortex tube and passes through nozzles that are tangent to to an internal counterbore (1). As the air passes through it is set into a spiraling vortex motion (2) at up to 1,000,000 rpm. The spinning stream of air flows down the hot tube in the form of a spinning shell, like a tornado (in red). The control valve (4) at the end allows some of the warmed air to escape (6) and what does not escape reverses direction and heads back down the tube as a second vortex (in blue) inside of the low pressure area of the larger warm air vortex. The inner vortex loses heat and exits the through the other end of as cold air (5).

It is thought that that both the hot and cold air streams rotate in the same direction at the same angular velocity, even though they are travelling in opposite directions. A particle of air in the inner stream completes one rotation in the same amount of time that an air particle in the outer stream. The principle of conservation of angular momentum would say that the rotational speed of the inner inner vortex should increase because the angular momentum of a rotating particle (L) is equal to the radius of rotation (r) times its mass (m) times its velocity (v).  L = r•m•v.  When an air particle moves from the outer stream to the inner stream, both its radius (r) and velocity (v) decrease, resulting in a lower angular momentum. To maintain an energy balance for the system, the energy that is lost from the inner stream is taken in by the outer stream as heat. Therefore, the outer vortex becomes warm and the inner vortex is cooled.

At EXAIR, we have harnessed the cooling power of the vortex tube, and it can be found and utilized in such products as Spot Coolers, Cabinet Coolers, and the Vortex Tube themselves.

Harnessing the cooling power of the vortex tube 

If you have questions about Vortex Tubes, or would like to talk about any of the EXAIR Intelligent Compressed Air® Products, 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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