An air-to-air heat exchanger uses the temperature differential between the ambient air surrounding an enclosure and the hot air inside an enclosure to create a cooling effect. A closed loop system exchanges the heat inside the enclosure with the outside air in an effort to maintain a set internal temperature. The heat exchange of most air-to-air unit relies on a heat pipe, a heat-transfer device which converts an internal refrigerant liquid into vapor by placing one end of the pipe in contact with the hot environment. The heated vapor travels to the other end of the pipe which is in contact with a cooler environment. The vapor condenses back into a liquid (releasing latent heat) and returning to the hot end of the pipe and the cycle repeats.
But, this type of solution does give some cause for concern, especially when considering their use in an industrial environment. Here are the key points to keep in mind when comparing an air-to-air cooler to an EXAIR Cabinet Cooler.
Required temperature differential based on ambient air temp
An air-to-air heat exchange relies on the ΔT between the ambient air temperature and the internal enclosure air temperature to produce cooling. If this ΔT is low, or the ambient temperature rises, cooling is diminished. This means that as the temperatures in your facility begin to rise, air-to-air heat exchangers become less and less effective. Larger air-to-air heat exchangers can be used, but these may be even larger than the enclosure itself.
EXAIR Cabinet Coolers rely on the ΔT between the cold air temperature from the Cabinet Cooler (normally ~20°F) and the desired internal enclosure temperature (normally 95°F). The cold air temperature from the Cabinet Cooler is unaffected by increases in ambient temperatures. The large ΔT and high volume cold air flow produced by a Cabinet Cooler results in more cooling capacity. And, we can increase cooling capacity from a Cabinet Cooler without increasing its physical footprint, which is already much, much smaller than an air-to-air type of unit.
Cooling in high temperature environments
Due to their nature of operation, an air-to-air heat exchanger must have an ambient temperature which is lower than the desired internal temperature of the enclosure. If the ambient air has a higher temperature, air-to-air units provide zero cooling.
Cabinet Coolers, on the other hand, can be used in hot, high temperature environments up to 200°F (93°C).
Cooling in dirty environments
Dirt in the ambient environment will impact cooling performance with an air-to-air heat exchanger. In order for the air-to-air unit to effectively remove heat, the heat pipe must have access to ambient air. With any exposure to the ambient environment comes the possibility for the ambient end of the heat pipe to become covered in ambient contaminants such as dust. This dust will create an insulation barrier between the heat pipe and the ambient air, decreasing the ability for the heat pipe to condense the vapors within. Because of this, most air-to-air devices use filters to separate the heat pipe from the ambient environment. But, when these filters become clogged, access to ambient temperatures are reduced, and cooling capacity of the air-to-air unit reduces as well.
Cabinet Coolers have no problem operating in dirty environments. In fact, it is one of their strengths. Without any moving parts to wear out or any need to contact ambient air for cooling purposes, a dirty environment poses no problems. In fact, check out this blog post (and this one) about EXAIR Cabinet Coolers operating maintenance free for years in dirty environments.
Size and time required to install
Air-to-air heat exchangers vary in size, but even the smallest units can have large dimensions. Many applications have limited space on the enclosure, and a large, bulky solution can be prohibitive. Couple this with the time and modification required to the enclosure to install a large air-to-air unit, and the “solution” may end up bringing additional problems.
Another key aspect of the Cabinet Cooler is its size. Small, compact, and easy to mount on the top or side of an enclosure, Cabinet Coolers install in minutes to remove overheating problems.
Heat within an electrical cabinet can be a major issue for manufacturing companies. The costs associated with downtime and repairs on sensitive electronics that fail due to heat or environmental contaminants, are an unnecessary burden. If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.
Jordan Shouse
Application Engineer
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