## Calculating CFM of Air Needed for Cooling

It’s easy to know that EXAIR’s vortex tubes can be used to cool down parts and other items, but did you know that our air knifes can be used to cool down these same things? It’s the same process that we do every day to cool down hot food by blowing on it. Every molecule and atom can carry a set amount of energy which is denoted by physical property called Specific Heat (Cp); this value is the ration of energy usually in Joules divided by the mass multiplied by the temperature (J/g°C). Knowing this value for one can calculate the amount of air required to cool down the object.

Starting out you should note a few standard values for this rough calculation; these values are the specific heat of Air and the specific heat of the material. Using these values and the basic heat equation we can figure out what the amount of energy is required to cool. The specific heat for dry air at sea level is going to be 1.05 J/g*C which is a good starting point for a rough calculation; as for the specific heat of the material will vary depending on the material used and the composition of the material.

If you have any questions about compressed air systems or want more information on any EXAIR’s of our products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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## EXAIR Cabinet Cooler Systems – How Do they Work?

Cabinet Cooler systems eliminate heat related problems by providing a temperature controlled environment inside of electrical enclosures. Typically set to maintain 95F (but also adjustable) a Cabinet Cooler system can withstand harsh, remote environments with little maintenance. They cool heat loads up to 5600 Btu/Hr and are UL listed to maintain your cabinet’s NEMA integrity.

Compressed air enters the vortex tube powered Cabinet Cooler and is converted into two streams, one hot and one cold. Hot air from the vortex tube is muffled and exhausted through the vortex tube exhaust. The cold air is discharged into the cabinet through the included cold air distribution kit. The displaced hot air in the cabinet rises and exhausts to atmosphere through the cabinet cooler body. The control cabinet is both cooled and purged with cool, clean air. Outside air is never able to enter the control panel.

EXAIR’s compressed air operated, Cabinet Cooler Systems are a low cost, reliable way to cool and purge electronic control panels. There are no moving parts to wear out and no filters to replace, eliminating the need for constant monitoring.

NEMA Type 12 (IP54) and NEMA 4 and 4X (IP66) models are available that are very compact and mount in just minutes through an ordinary electrical knockout.

Available in a wide range of cooling capacities, ranging from 275 Btu/hr. for our smallest system, up to 5,600 Btu/hr. for our largest Dual System.

Thermostat control systems are the most efficient way to operate a Cabinet Cooler as they limit compressed air use by operating only when the temperature inside the enclosure approaches critical levels. Continuous Operating Systems are recommend when constant cooling and constant positive pressure inside the panel is required.

Thermostat controlled Cabinet Cooler Systems are the best option when experiencing fluctuating heat loads caused by environment or seasonal changes. Thermostatically Controlled Systems include a Cabinet Cooler, adjustable thermostat, solenoid valve, cold air distribution kit consisting of tubing and self adhesive clips to duct the cold air inside the panel and a filter separator to remove any water or contaminants from the supply.

If you would like to discuss our cabinet cooler systems or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Jordan Shouse
Application Engineer
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## Cold Guns for Spot Cooling or Replacing Mist Systems

By using only a source of compressed air, the and High Power Cold Gun produces a stream of clean, cold air 50°F (28°C) below your compressed air supply temperature. The Cold Gun is very quiet at only 70 dBA and has no moving parts to wear out. Just supply it with clean compressed air and it’s maintenance free.

How does it work, and what are the benefits?

• The Cold Gun uses compressed air to produce a stream of clean, cold air at 50°F (28°C) below supply air temperature. Generally this will be 20°F-30°F outlet 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 when replacing expensive mist systems.
• 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 version to meet your specific needs.

We also offer Single & Dual Point Hose Kits, to further meet the needs of your application.

One of the best applications I have seen with our cold gun came from a customer in Peru. They are a gold mining operation and they were having trouble with the liquid they were using to cool a saw. Read all about it here!

If you have an application that you believe would be better served by the use of an EXAIR Cold Gun,

Jordan Shouse
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.

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)

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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## 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.

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.

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

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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## Vortex Tube Overview

A Vortex Tube uses an ordinary supply of compressed air as a power source, creating two streams of air, one hot and one cold – resulting in a low cost, reliable, maintenance free source of cold air for spot cooling solutions.

The EXAIR Vortex tubes are made of stainless steel, which provides resistance to wear, corrosion and oxidation – ensuring years of reliable, maintenance free operation

The cold air flow and temperature are easily controlled by adjusting the slotted valve in the hot air outlet.  Opening the valve reduces the cold air flow and the cold air temperature.  Closing the valve increases the cold air flow and and the cold air temperature.

EXAIR Vortex Tubes come in three sizes. Within each size, a number of flow rates, which are dictated by a small internal generator, are available. Selection of the appropriate Vortex Tube can be achieved either by knowing the BTU/hr (Kcal/hr) requirements or the desired flow and temperature requirements. Selection is then based on the specification table (BTU/hr or Kcal/hr is known) or the performance tables (flow and temperature is known.)

The performance of a Vortex Tube is reduced with back pressure on the cold air exhaust. Low back pressures up to 2 PSIG ( 0.1 Bar) will not change performance and a 5 PSIG (0.3 Bar) will change the temperature drop by approximately 5°F (2.8°C)

The use of clean air is essential, and filtration of 25 microns or less is recommended.  EXAIR offers filters with 5 micron elements and properly sized for flow.

A Vortex Tube provides a temperature drop to the incoming supply air.  High inlet temperatures will result in a corresponding rise in the cold air temperature.

EXAIR offers mufflers for both the hot and cold air discharge.  If the cold air is ducted, muffling may not be required.

For best performance, operation at 80 to 110 PSIG (5.5 to 7.6 Bar) of supply pressure is recommended. The Vortex Tubes have a maximum pressure rating of 250 PSIG (17.2 Bar) and a minimum requirement of 20 PSIG (1.4 Bar)

To discuss your application and how a Vortex Tube or any EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR, myself, or one of our other Application Engineers. We can help you determine the best solution!

Brian Bergmann
Application Engineer

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## Cool Small Parts and Tools, with Clean, Cold Air

Do you need a proven way to reduce downtime and increase productivity on a variety of operations involving small parts where heat is a problem?  EXAIR‘s Mini Cooler produces a stream of 20°F (-7°C) cold air to prevent heat build up and blow away chips and debris.

Especially effective on high speed operations, the Mini Cooler helps to prevent burning, melting, and heat related breakage, and while doing so, at a quiet 76 dBA sound level. Better yet, all done with no moving parts to wear out.

Some popular applications for the Mini Cooler are – small tool cooling, needle cooling, blade cooling, and lens grinding.

There are several advantages to take note of – low cost, increased production rates, better tolerances, and quiet and compact.

The Mini Cooler Systems are available with One or Two Cold Outlets, and also include a 1″ wide Flare Nozzle Tip, and a Manual Drain Air Filter to clean the air, ensuring long, trouble free operation.

Using just 8 SCFM of 100 PSIG compressed air, the Mini Cooler will not tax your compressed air system.  Its small size allows it to fit in areas where larger systems could not fit.  The powerful magnetic base sticks to any ferrous surface and and provides up to 100 pounds of pull force.

If you have any questions about the Mini Cooler, the Adjustable Spot Cooler, Cold Gun or any EXAIR 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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