As U.S. manufacturing continues to provide a catalyst to the economy, automation within manufacturing facilities continues to expand. The electronic components necessary to automate machines and processes also require a cool, clean environment to operate.

The surroundings these components typically are set in, however, subject them to high ambient temperatures, dirty ambient air, high humidity or wet and corrosive environments. Obviously, electronics in these environments are vulnerable to overheating and failure. Yet, companies expect that these electronic components will function no matter the surroundings and have little patience - or downtime available - to handle the costs associated with repairs and lost production. Proper protection and cooling of these electronic components is paramount for maintaining a smooth operation.

Components themselves also are part of the problem because they release heat into the control cabinet as they operate, which creates an internal heat load. Some heat-producing components include variable-frequency drives, transformers, soft starts, power supplies, batteries, central processing units (CPUs) and similar components.

External heat load is the second part of the overheating problem. Many of these controls are placed in compressor rooms, near furnaces and ovens, or outside in the sun, in hot, non-air conditioned factories and other unfriendly locations that demand cooling.

Vortex Tube Cabinet Cooling

Using vortex tube-based cabinet cooler systems provides a relatively low cost, reliable way to cool and purge electronic cabinets. Vortex-tube coolers provide cold air from a source of compressed air and do not have any moving parts, which makes them reliable and low maintenance.

Vortex tubes use the pressure from compressed air to spin the air up to 1,000,000 rpm. The outer vortex revolves around the tube toward a control valve, where some of the air escapes as hot air. The remaining air is forced back through the center of the outer vortex and gives off kinetic energy - in the form of heat - to the outer stream, creating a cold air stream that exits the opposite end of the control valve. These coolers can provide capacities up to 5,600 BTUs per hour.

Vortex tube coolers allow fast installation that makes them suited to deal with seasonal overheating emergencies or unexpected heat-related downtime. They are installed through a hole through the enclosure, typically no larger than 2" in diameter. With a hole in place, the cooler is locked in position with a nut from the inside of the cabinet, creating the NEMA-rated seal. Little internal space is required for vortex tube coolers because the bulk of the product remains outside of the enclosure. For applications with limited external space, some manufacturers supply a side-mounting kit or coolers that can be mounted on any cabinet wall in any orientation.

A source of clean dry air is required and most manufacturers integrate the necessary compressed air filter into a cooler system. Filters prevent any dirt or condensate from the compressed air source from entering the cabinet. Typically, filter replacement is relatively inexpensive and simple. The filter element should be checked annually and replaced as needed based upon cooler usage. Cabinet cooler systems provide a slight positive pressure within an enclosure that aids in keeping dust, dirt and debris outside. A built-in air exhaust designed into the cooler’s construction prevents any additional need for a vent. Because vortex coolers do not have any moving parts that can break down, the lifetime of these products can be more than 20 years.

Vortex tube technology is not the same as heat exchanger technology and will not be affected by fluctuating ambient temperatures. Heat exchangers rely on ambient air and lose their cooling capacity due to elevated external temperatures. Because vortex tube coolers operate independently from an ambient air source - relying on the compressed air source - they are suited for areas or seasons with high ambient air temperature.

Vortex tube cabinet coolers typically produce consistent temperatures. For instance, a cooler system using a bimetal contact thermostat has a typical tolerance of ±2°F. Some manufacturers offer digital thermostats with ±1°F.  The thermostat will turn the cooler on and off only as needed to maintain a specific internal cabinet temperature. The internal temperature can be adjusted to decrease the amount of time a cooler will be running while still producing an appropriate temperature for the electric components. For users with seasonal heat problems, thermostatically controlled vortex coolers can shut themselves off in the cool winter months and on at the first sign of summer, preventing emergency heat-related problems.

Many facilities require something to cool down the electronics within control cabinets. Vortex tube cabinet cooler systems provide ease of installation, tight temperature tolerances, durability and reliability. PC

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