Kooltronic Blog

An air-to-air heat exchanger uses a specialized heat transfer element and two separate airflows to remove heat from an electrical enclosure. In this closed-loop enclosure cooling system, the air surrounding components is passed through either a coil with refrigerant or a convoluted metal foil element to remove excess heat. The cooled air is then routed back into the sealed enclosure while the heated air is forced out of the system.

Advanced air-to-air heat exchanger systems are designed to cool enclosures using one of the following heat transfer methods:

1. A finned-tube coil containing liquid refrigerant.
   
   In this design, the warm air exhausted from the enclosure to the heat exchanger is directed past the coil, causing the refrigerant to boil and absorb heat. The resultant refrigerant vapor rises to the upper portion of the tubes, where the heat is removed by the cooler ambient air and the refrigerant condenses back to liquid, completing the cooling cycle. This continuous process is illustrated in the diagram below.
   
   
   
   
2. High-efficiency heat transfer elements.
   
   Some air-to-air heat exchanger designs employ high-efficiency heat transfer elements fabricated of embossed convoluted metal foil or thin-film polymer material, constructed into two separate air paths. The hot air leaving the electrical enclosure is directed through one side of the heat exchanger, where it passes through the element walls into the ambient-side air stream and dissipated.

Air-to-air heat exchangers may be an ideal choice for certain applications that can tolerate operating temperatures slightly above that of ambient. Also, the closed-loop design of air-to-air heat exchangers protects the enclosure interior and isolates sensitive components from the external environment – making them an excellent consideration for applications where dust and other airborne contaminants are prevalent.

Most Kooltronic Heat Exchangers are designed for installation in indoor environments. For outdoor operation or applications requiring washdown, Kooltronic offers NEMA 4 and NEMA 4X rated air-to-air heat exchangers which feature weather protection and other special protective features.

If you have any questions about heat exchangers, air conditioners, fans, or other enclosure cooling products, we invite you to contact the experts at Kooltronic. For over 65 years, we have been helping customers find the right enclosure cooling solution for unique and challenging applications.