Debunking 4 Air to Air Heat Exchanger Myths
Although air to air heat exchangers have been around for many years, there are misconceptions about how they work and why they are so useful. Many are skeptical about this form of cooling and feel that it’s no better than fan-assisted cooling or natural ventilation. The truth is air to air heat exchangers are a viable alternative to other cooling solutions. Here are a few myths that are commonly mentioned.
Myth #1: They Are Inefficient
Some feel that the air to air heat exchanger is inefficient and not worth considering. Nothing could be further from the truth: they are just about the most efficient cooling solution available. The secret of this system is the partially evacuated heat pipe injected with a refrigerant. The bottom of the heat pipe is exposed to the hot air from the enclosure, causing the refrigerant to vaporize. At the top of the heat pipe, the refrigerant vapor, cooled by outside air, condenses and releases heat. The liquid refrigerant then flows back to the bottom. This cycle is continuous. The only power requirement is for two small fans that circulate air from the enclosure to the pipe and to disperse hot air released by the pipe.
Myth #2: They Have Extremely Limited Capacity
An air to air heat exchanger works on the temperature differential between the warmer enclosure and cooler outside air. The greater the temperature difference, the better the cooling. Assuming a temperature difference of 10 °F, larger heat exchangers will remove as much as 400 watts of heat.
Because they operate on a closed air loop, they are designed for use with sealed enclosures that protect electrical equipment from damage due to the ingress of dirt and dust
Myth #3: A Heat Exchanger Is No Better Than Fans
This is one of the more common myths, and it has its basis in the fact that both air to air heat exchangers and filtered fan packages remove heat from an enclosure but are unable to cool the enclosure to below ambient temperature. However, an enclosure cooled by filtered fans is open to the environment and this allows a certain amount of dust and dirt to enter the enclosure, depending upon the efficiency of any air filters employed. Additionally, filters become choked in dirty locations unless regularly maintained. On the other hand, an enclosure cooled by an air to air heat exchanger is sealed so dust and dirt cannot enter and contaminate equipment.
Myth #4: They’re Not Suitable for Harsh Environments
Air to air heat exchangers are available for various NEMA enclosure ratings including NEMA Type 12, 4 and 4X. A NEMA Type 12 enclosure is suitable for indoor use with protection against circulating dust. NEMA Type 4 enclosures are designed for indoor and outdoor use and provide protection against severe dust, rain, sleet, and snow, and these enclosures can be hosed down. NEMA Type 4X enclosures, designed for extremely harsh environments, provide additional protection against corrosive atmospheres, including corrosive chemicals and salt spray. Housings of air to air heat exchangers designed to withstand corrosion are made of stainless steel for added protection and long life.
Selecting an Air to Air Heat Exchanger
Look for a cooling solution that is UL listed (U.S. and Canada) to provide prospective users added peace of mind. Units should be designed for arduous industrial use with robustly constructed enclosures. Energy efficiency and maintenance requirements should also be top of mind. Look for various fan supply voltages, including DC options, to meet a range of needs.
The Thermal Edge air to air heat exchanger is the most economical solution available for sealed enclosures in terms of initial cost, cooling efficiency and operating cost. Contact our National Sales Team and discover how to solve your enclosure cooling issues.