EXAIR Cabinet Cooler Systems Vs. Refrigerant-Based Panel Cooling Options

If you’ve got an electrical enclosure that needs heat protection, you’ve got a good number of options at your disposal. Frankly, if any one of them were the “be-all and end-all” solution, the rest of us would be looking for something else to do. Fact is, there are certain situations where one particular method makes more sense than the others, and other situations where one method just won’t work but several others will.

In industrial and commercial settings, these situations will often present conditions where there is indeed an ideal solution. Today, we’ll explore the ones where the choice comes down to a compressed air-operated EXAIR Cabinet Cooler System or refrigerant-based panel cooling.  Let’s consider:

Environment – Now, we’re all going to make sure we protect our gear from the elements, as much as is humanly possible. Your company’s computer server is likely a lot closer to the climate controlled office spaces than the welding or grinding stations. But what happens when sensitive electronics need to be in close proximity to the machinery they’re controlling? And that machinery isn’t in climate controlled office spaces?

EXAIR NEMA 4 Cabinet Cooler System on an enclosure in a hot steel mill.

Even if an A/C type panel cooler would fit on this box, it would be problematic:

  • See all that dust on the ducts? And the belt? And the rails? And the…well, everywhere? Yeah; would be in the filters, condenser coils, the compressor motor bearings and eventually, inside the panel.
  • They make condensate. The big thing about air conditioners is that they lower the humidity…and that water has to go somewhere. Even if a small drain line is easy enough to run, what happens when it gets clogged (that dust is going to find its way here too, by the way)?
  • They’re sensitive to vibration. Every fastener, every brazed joint, every electrical connection, risks cyclical failure if they’re shaken about.

EXAIR Cabinet Cooler Systems are impervious to all of these conditions:

  • The only air they use comes straight from your compressed air supply. We even provide Automatic Drain Filter Separators to make sure this is clean & dry.
  • There are no moving parts. Vibration is not a problem.
  • We offer different levels environmental considerations to meet most any challenge:
    *NEMA 12 (dust tight, oil tight) are ideal for general industrial environments.
    *NEMA 4 (splash resistant) keep liquids out too, and are indoor/outdoor rated.
    *NEMA 4X (corrosion resistant) also keep liquids out, and are stainless steel construction. They’re also available in 316SS construction for the most exacting, harshest, and critical environments such as food service, pharmaceutical, or highly corrosive atmospheres.
    *High Temperature Cabinet Cooler Systems are specified for installation in areas where ambient temperatures exceed 120°F (52°C.)

Location – Sometimes, there’s just not room to mount an air conditioner. The compressor, and, especially, the condenser coils have to take up a finite amount of space, by design.

When there’s no room to use a bulky air conditioner, a compact EXAIR Cabinet Cooler System is ideal.

EXAIR Cabinet Cooler Systems have a small footprint…a NEMA 12 550 Btu/hr system, for example, installs through a ½ NPS knockout, is under 6” tall, and just over 1” in diameter.

Reliability – We talk to callers all the time about the frustration of:

  • Having to replace a burned out Variable Frequency Drive because their panel cooler failed.
  • Constantly resetting controls that have tripped due to an overheat condition because they missed, or don’t have time for, their panel cooler’s maintenance.
  • Down time and lost production while waiting for replacement parts…or a whole new panel cooler.

Even in less aggressive environments, filters and coils can slowly accumulate dirty buildup, which reduces the unit’s cooling power.  Then, a heat wave hits early in the season, and your machine trips out (if you’re lucky) or burns out (if you’re not) -either way, that part or process you were in the middle of is scrap, and you’re back to step one.

EXAIR Cabinet Cooler Systems are not affected by this – in fact, a system with thermostat control may just sit there dormant through the winter, and “spring” (pun intended) into action when that first heat wave rolls through.  And it’ll be just as powerful as that last hot day, the previous autumn.

Availability – Let’s say you installed some new equipment recently, and its first exposure to the heat of summer created one of the frustrating situations above.  An air conditioner-type panel cooler will require:

  • “Invasive surgery” on your enclosure. Most of these require a sizeable rectangular hole for installation.
  • These systems can pull 5 amps or more, which might mean a dedicated circuit breaker & wiring.
  • Many are built-to-order, so you might have to wait, depending on their assembly schedule.  And they might be busy, because if the heat just started causing you problems, you’re probably not the only one.
  • Once it’s received, installed, and wired up, you may still have to wait for the compressor’s oil (special oil for use with refrigerant) to settle before you start it up the first time.

EXAIR Cabinet Cooler Systems are stock products.  We ship same day, across the country, with orders received by 3pm EST.  They install in minutes, and most of the preparation can be done today, so you’re ready to install when it comes in tomorrow – which isn’t a big deal…most Cabinet Cooler Systems weigh only 5lbs or less, so expedited shipping isn’t near as painful to your wallet as a big box full of electric motor, copper coil, and refrigerant.

Environment (friendly, that is) – No matter how well they’re built, a refrigerant system is going to leak sooner or later.  And every whiff through an aging seal, or sudden loss through a failed tube, will contribute to the ozone depletion that today’s strict controls and high attention to CFC’s are trying to prevent.

Our Cabinet Cooler Systems are solely compressed air operated…the only thing they exhaust is the air from inside the enclosure.

Durability – Refrigerant leaks. Electric motors wear out.  Coils corrode.  Filters clog.  A GOOD warranty on an air conditioning type panel cooler is two years.  And it won’t cover environmental effects.

All EXAIR Compressed Air Products have a Five Year Built To Last Warranty.  But if you supply your Cabinet Cooler System with clean, dry air, it’s going to run darn near indefinitely, maintenance free.

Don’t trust your critical electronics to anything less than the assurance provided by an EXAIR Cabinet Cooler System. If you’d like to find out which one(s) are right for your needs, give me a call.

Russ Bowman
Application Engineer
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BTU/hr. vs. Cold Air Temperature

 

Way back in 1983 the founder of EXAIR began producing Vortex Tubes.  Using only compressed air, these small devices produce extremely cold air through the Ranque-Hilsch effect.  As the compressed air enters the Vortex Tube, it begins to spin, reaching over 1,000,000 rpm.  When the spinning airflow reaches the end of the tube, an adjustable percentage is forced to change directions and decrease in diameter.  This decrease in diameter requires a decrease in energy, which the airflow does in the form of heat.  What is left is a hot airstream from one end of the tube and a cold airstream from the other.

An EXAIR Vortex Tube

A key component in the creation of the Vortex Tube effect is the apparatus which starts the spinning of the air inside the tube.  At EXAIR we refer to this piece as the generator, and we can significantly impact the performance of the Vortex Tube based on the dimensional characteristics of this component.

By changing one dimension of the generator we can increase or decrease the total volume of air which flows through the Vortex Tube; and by changing another dimension we can “force” a certain percentage of air to exit the hot end of the Vortex Tube.  These small dimensional changes will result in either a high volume of very cold air, or a low volume of INSANELY cold air.  So, how is this possible?

EXAIR Vortex Tube Performance Chart

To thoroughly answer this, we have to look at something called cold fraction.  A cold fraction is the percentage of air which enters the Vortex Tube and exhausts through the cold end.  An 80% cold fraction will direct 80% of the air which enters the Vortex Tube to exhaust through the cold end.  For example, using a 10 SCFM Vortex Tube with an 80% cold fraction will produce 8 SCFM of flow through the cold end of the tube and 2 SCFM of flow through the hot end of the tube.

Adjusting the cold fraction of a Vortex Tube is as simple as turning the brass valve on the hot end of the tube.  The more the valve is opened, the lower the cold fraction.  As the valve is opened it allows more air to “escape” the Vortex Tube through the hot end, resulting in a lower flow (and also lower temperature air) from the cold end of the tube.  These cold fractions determine the temperature drop of the incoming compressed air, and therefore the outlet temperature of the cold air from the Vortex Tube.  But, this adjustment limited, based on the geometry of the generator mentioned above.

An EXAIR Cooling Kit, complete with Vortex Tube, cold air muffler, generator kit, and automatic drain filter separator.

At EXAIR we produce multiple styles of Vortex Tube generators which produce different cold fraction bandwidths.  Our “C” style generators are better suited to produce a cold fraction between 0-60%, and our “R” style generators are better suited to produce a cold fraction between 40-100%.  These cold fractions are independent of airflow volume, allowing for different outlet temperature ranges with the same inlet compressed air volume.  (You will notice some overlap of cold fraction in the 40-60% range.  Generally, our practice is to use “R” style generators down to 50% cold fraction.)

So, which one is better?

The answer depends on the target temperature needed in the application.  If the absolute coldest temperature is necessary, such as when trying to reach more of a cryogenic type of temperature on a small component or for a test, a “C” style generator may be the best choice.  But, if maximum cooling power is needed, the “R” style generator will prove to have an advantage.  It may seem counter-intuitive at first, but extremely low temperature air from a “C” style generator at less volume will produce less cooling effect than the moderately low temperature air at higher volume from an “R” style generator.

To illustrate this effect, let’s take a look at calculating BTU/hr. of a Vortex Tube.  This is done in the following steps:

  1. Determine inlet airflow to the Vortex Tube.
  2. Determine cold flow value at specified cold fraction.
  3. Use the cold fraction chart to determine temperature drop of incoming compressed air.
  4. Subtract temperature drop from the temperature of the incoming air.
  5. Determine the ΔT between the temperature of the air you are producing and the required temperature in the application.
  6. Place these values into the refrigeration formula shown below.

 

1.0746 x Cold Flow in SCFM (step 2 value) x ΔT in °F (step 5 value) = BTU/hr.

 

Now, using the process above, let’s compare a “C” style Vortex Tube and an “R” style Vortex Tube in terms of BTU/hr.  For this exercise we will compare a model 3425 “C” style Vortex Tube with a model 3225 “R” style Vortex Tube, using a supply pressure of 100 PSIG and a compressed air temperature of 70°F.

Calculations for model 3425 “C” style Vortex Tube

  1. Determine inlet airflow to the Vortex Tube.
    1. 25 SCFM
  2. Determine cold flow value at specified cold fraction.
    1. With a range of 0-60%, we will utilize a value of 40% for this comparison. This will yield a cold flow volume of 10 SCFM.
  3. Use the cold fraction chart to determine temperature drop of incoming compressed air.
  4. Subtract temperature drop from the temperature of the incoming air.
    1. At a supply pressure of 100 PSIG and 40% cold fraction, the temperature drop will be 110°F. With a compressed air temperature of 70°F we will have an outlet temperature of -40°F.
  5. Determine the ΔT between the temperature of the air you are producing and the required temperature in the application.
    1. An application using a “C” style generator will normally have a low target temperature, such as 0°F. This will yield a ΔT of 40°F.
  6. Place these values into the refrigeration formula shown below.

 

1.0746 x Cold Flow in SCFM (10 SCFM) x ΔT in °F (40°F) = 430 BTU/hr.

 

Calculations for model 3225 “R” style Vortex Tube

  1. Determine inlet airflow to the Vortex Tube.
    1. 25 SCFM
  2. Determine cold flow value at specified cold fraction.
    1. With a range of 50-100%, we will utilize a value of 70% for this comparison. This will yield a cold flow volume of 17.5 SCFM.
  3. Use the cold fraction chart to determine temperature drop of incoming compressed air.
  4. Subtract temperature drop from the temperature of the incoming air.
    1. At a supply pressure of 100 PSIG and 70% cold fraction, the temperature drop will be 71°F. With a compressed air temperature of 70°F we will have an outlet temperature of -1°F.
  5. Determine the ΔT between the temperature of the air you are producing and the required temperature in the application.
    1. For most applications using an “R” style generator we aim for a target temperature of 95°F. This will yield a ΔT of 96°F.
  6. Place these values into the refrigeration formula shown below.

 

1.0746 x Cold Flow in SCFM (17.5 SCFM) x ΔT in °F (96°F) = 1,805 BTU/hr.

 

In this comparison we have proven that although the “C” style Vortex Tube will produce a lower temperature airflow, it will not produce a greater cooling effect in an application.  Maximum cooling is achieved with the “R” style generator.  For this reason, 9 out of 10 applications utilize the “R” style 3200 series EXAIR Vortex Tube.  These units produce an extremely cold output air with high volume to effectively remove heat.  The “C” style units are also effective at removing heat, but are normally suited for applications aiming to achieve the lowest temperature airflow possible.

But, no matter the style of generator installed into the Vortex Tube, the cold air output is useful for industrial applications.  Whether the need is for spot cooling electronic components, grinding wheels, milling and drilling equipment, or laser cutting heads, we have a Vortex Tube solution.  If you have an application and would like to discuss an EXAIR Vortex Tube solution, contact our Application Engineers.  We’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

EXAIR Vortex Tubes: As Much Cold Air As You Need, As Cold As You Need It

If you’re looking for a reliable, consistent flow of cold air, there’s really no better way to produce it than with a Vortex Tube. There are no moving parts…the air flow and temperature from a particular model, set to a specific cold fraction, is only influenced by the compressed air supply pressure & temperature.

Pressure is easy to control…all you need is a suitable regulator.  Temperature CAN be a variable, depending on your type of compressor, if you have a dryer system (and what type it is,) and sometimes, ambient conditions…if, for example, a long pipe is run through a very hot environment like a foundry or a blast furnace operation.  In cases where supply pressure and/or temperature can be limitations, a higher capacity Vortex Tube, set to a lower Cold Fraction, may be specified.  Which brings me to the user inquiry that inspired today’s blog…

This particular customer uses our Model 3215 Vortex Tubes (15 SCFM, 1,000 Btu/hr) to provide cooling to analyzer systems that monitor certain quality parameters in their manufacturing processes.  The ability to precisely control the temperature in these systems makes for repeatable and accurate measurement of these parameters.   Their compressed air supply in this area is regulated to 80psig, they have a refrigerant-type dryer and climate-controlled facility, so their supply temperature is a consistent 70°F.  You couldn’t ask for better conditions for a successful Vortex Tube application, and they’ve worked great, for years.

Now, due to a plant expansion, they’re installing some of these analyzer systems in a location where the compressed air supply is limited to 60psig.  The required cooling capacity is going to be the same, so the Project Manager reached out to us to see if they could get the same amount of cooling with this new pressure limitation.  Here’s how they’re doing it:

We publish the rated performance of Vortex Tube products for a supply pressure of 100psig.  The Model 3215 Vortex Tube consumes 15 SCFM @100psig and, when set to an 80% Cold Fraction (meaning 80%…or 12 SCFM…of the 15 SCFM supply is directed to the cold end,) the cold air will be 54F colder than the compressed air supply temperature.  Here’s the performance table, so you can follow along:

EXAIR Vortex Tube Performance Table

Now, their supply is at 80psig.  Since air consumption is directly proportional to absolute supply pressure (gauge pressure PLUS atmospheric, which is 14.7psi at sea level,) we can calculate their units’ consumption as follows:

(80psig + 14.7psia) ÷ (100psig + 14.7psia) = 0.83 X 15 SCFM (@100psig) = 12.4 SCFM (@80psig)

So, with a 50°F temperature drop (from a supply @70°F,) they were getting 12.4 SCFM of cold air at 20°F.

As you can see from the table above, they’ll only get a 46°F drop at 60psig…and the flow won’t be as high, either.  So…we’ll need to get more air through the Vortex Tube, right?  Let’s use a little math to solve for what we need.

We still need 20°F cold air from 70°F compressed air, so, at 60psig, we’re looking at a Cold Fraction of ~70%.  And we still need 12.4 SCFM, so:

12.4 SCFM ÷ 0.7 = 17.7 SCFM @60psig (required supply)

Our Model 3230 Vortex Tube uses 30 SCFM @10opsig…at 60psig it’ll consume:

(60psig + 14.7psia) ÷ (100psig + 14.7psia) = 0.65 X 30 SCFM (@100psig) = 19.5 SCFM (@60psig)

That’s about 10% more flow than they needed, theoretically, which was close enough to start.  From there, they “dialed in” performance by regulating the supply pressure and Cold Fraction (see video, below):

If you’d like to find out more, or work through a cooling application, give me a call.

Russ Bowman
Application Engineer
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Controlling Temperature And Flow Of An EXAIR Vortex Tube

If you need a reliable, consistent flow of cold air, look no further than the EXAIR Vortex Tube:

A 1/4 ton of refrigeration in the palm of your hand!

Getting the performance you want comes down to answering two simple questions:

What temperature do I need? 

Vortex Tubes produce a DROP in temperature, so your compressed air supply temperature is our starting point to determine what the actual cold air temperature will be.  The magnitude of the temperature drop is dependent on two factors:

  • Compressed air supply pressure – the higher the pressure, the higher the temperature drop.
  • Cold Fraction setting of the Vortex Tube – this is the percentage of the air supply that’s directed to the cold end.  The same temperature drop is produced, regardless of model, for a given Cold Fraction.  The lower the Cold Fraction, the greater the temperature drop (and hence, the lower the air temperature.)

EXAIR has two distinct series, or types, of Vortex Tubes:

3200 Series are used when Cold Fractions above 50% are desirable.  This provides maximum refrigeration…high flows and temperature drops that are optimal for many spot cooling applications such as tool cooling, setting hot melt adhesives, quick cooling of soldering/brazing, etc.

3400 Series are used for lower Cold Fractions (below 50%) and generate VERY cold air flow…as low as -50°F.  Some common applications for these are cryogenic lab sample cooling, circuit testing, or freeze seals in certain piping systems.

Temperature drops are dependent only on supply pressure and Cold Fraction setting. These values apply to any Vortex Tube, regardless of size/model.

Cold Fraction is adjusted by turning the Hot Air Exhaust Valve to let more, or less, hot air out, as shown in this short video:

What flow do I need?

Both the 3200 and 3400 Series Vortex Tubes are offered, from stock, in twelve distinct models of each series.  These are defined by the compressed air consumption, and the cold air flow is determined by the Cold Fraction setting.

Small Vortex Tubes come in three Models for each series, and consume 2, 4, or 8 SCFM when supplied with compressed air @100 psig.

Medium Vortex Tubes come in five Models for each series, and consume 10, 15, 25, 30, or 40 SCFM @100 psig.

Large Vortex Tubes come in four Models for each series, and consume 50, 75, 100, or 150 SCFM @100 psig.

Converting a Vortex Tube to a different Model (in the same size class) is as easy as changing the Generator (and the Taper Sleeve, for the Small Vortex Tubes):

The Generator and Taper Sleeve (*Small VT’s only) are changed by removing the Cold Cap.

So, for example, if you have a Model 3210 (10 SCFM consumption, 1,000 Btu/hr rated cooling) set to an 80% Cold Fraction, supplied with compressed air @100 psig & 70°F, it’s making a 16°F cold air flow of 8 SCFM.  If your situation calls for more flow, you can change the Generator…for example, if you convert it to a Model 3240 (40 SCFM, 2,800 Btu/hr rated cooling) – leaving the Cold Fraction at 80%, you’ll now get 32 SCFM of 16°F air.

What if you need colder air?  You can convert this same Medium Vortex Tube to a Model 3440 (40 SCFM consumption, max cold temperature) by changing the Generator again…and if you lower the Cold Fraction to 20%, it’ll make a -53°F cold flow of 8 SCFM.

Powerful and versatile, EXAIR Vortex Tubes are suitable for a wide range of applications requiring a consistent and reliable flow of cold air.  For help in selecting the right one for your needs, give me a call.

Russ Bowman
Application Engineer
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Vortex Tube Kits Make Heat Removal A (Cool) Breeze

I recently had the pleasure of discussing a cooling application with a customer.  The caller was familiar with our Cabinet Cooler Systems, and wanted to incorporate the same technology into a spot cooling application.  Problem was, he wasn’t sure about exactly how much cold air flow, and at what temperature, would suit his needs best…this was on a brand new mold (for plastic parts) that had just arrived.  His idea was to order a few different Vortex Tubes, and experiment with them.

I agreed that trying a few different Vortex Tube models would be a quick and easy way to find a solution, but I had a quicker and easier way: the Model 3930 Medium Vortex Tube Cooling Kit.  This gave him all the Generators that fit the Medium Vortex Tube, allowing him to make any medium Vortex Tube model he desired.  He would also be able to adjust the Cold Fraction to get the most effective temperature drop as well.

EXAIR Vortex Tube Cooling Kits come with all parts necessary to effect a wide range of cold air flow & temperatures.

With the Vortex Tube in place, it was very easy to configure the optimal cooling…as he decreased the Cold Fraction (to get colder air) he replaced the Generator (to get higher air flow.)  His application (cooling molded plastic parts) was satisfied with a Model 3225, set to a 70% Cold Fraction…this gave him 17.5 SCFM of cold air flow, at temperature of around 0F (a 71F drop from their compressed air supply temperature, which is around 70F.)

Is an EXAIR Cooling Kit right for your heat removal application?  If you’d like to find out,  give me a call.

Russ Bowman
Application Engineer
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Video Blog: Medium Vortex Tube Cooling Kit

EXAIR offers (3) Vortex Tube Cooling Kits, and the video below will provide an overview of the medium size offering, for refrigeration up to 2800 BTU/hr (706 Kcal/hr.)

If you have questions regarding Vortex Tube Cooling Kits or any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Cabinet Cooler Systems Save The Day, Every Day

Summertime temperatures get hot. Protect your electronics with an EXAIR Cabinet Cooler System.

As you may have seen in our most recent E-NEWS Special Bulletin, or experienced in real life (depending on where you’re located,) most of the eastern United States is seeing a pretty significant heat wave for early summer…or, as we call it at EXAIR, “Cabinet Cooler Season.”  And this year is kicking it off with a bang, for sure.

On Tuesday, when the E-NEWS email went out, I was on the phone, processing an order for a Model 4340 NEMA 12, 2,800 Btu/hr, Thermostat Controlled Cabinet Cooler System, to ship overnight to a user who wanted to protect the new drive they were replacing because theirs overheated.  They were up and running before noon on Wednesday.

On Wednesday, four local customers placed “will call” orders for Cabinet Cooler Systems.  I had the pleasure of talking with one of them, who was installing one for the very first time.  As he was looking over the Installation & Operation Guide before he left our building, he just wanted to make sure that hooking it up was as simple as it sounded…and it is.  We pulled the parts from the box and went over exactly how each step is performed, and he left feeling confident that he’d have it installed pretty quickly.  Just in case, I also got his email address and sent him a link to our NEMA 4 Cabinet Cooler System Installation Video Blog:

I don’t know what the rest of the summer holds in store, but I know this: if you have concerns about protecting sensitive, critical, and/or expensive electrical & electronic enclosures, EXAIR Cabinet Cooler Systems are the solution you’re looking for.  Easy to install.  Maintenance free operation.  Durable, UL Listed, and CE Compliant.  If you’d like to discuss your application and get one for yourself, call me; let’s talk.

***Order an EXAIR Cabinet Cooler System before July 31, 2017, and get a FREE AC Sensor!***

Russ Bowman
Application Engineer
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