There are several ways to regulate the temperature within an electrical enclosure or control panel. Two of the most common methods include open-loop cooling (forced ventilation) and closed-loop cooling. Before deciding on a cabinet cooling product type, one should consider all application requirements, installation options, and environmental conditions. Understanding factors such as heat load, operating voltage, and NEMA rating will help narrow one’s enclosure cooling choices. Additionally, an enclosure cooling calculator can be a great tool to help determine the best product for the application.
Forced Ventilation Air Cooling
A simple forced-air cabinet cooling system utilizing ambient air is usually adequate in clean, non-hazardous environments with acceptable ambient temperatures. There are two airflow options when open-loop cooling is used on an enclosure: one is to pressurize the enclosure, and the other is to create a vacuum. Of the two options, pressurizing is preferred because it will utilize all louvers, racks, and openings as part of the exhaust flow, rather than pulling in air and possibly dirt. When combined with a low-cost air filter, ventilation devices generally meet the heat removal needs of standard electrical components. However, it is important to keep in mind that the maximum recommended air temperatures for operation may vary by electronic device type (for more information on this, see page 3 of the Kooltronic whitepaper, Increasing the Lifespan and Reliability of Electronic Components).
Closed-Loop Cooling
Many environments necessitate that ambient air is kept out of the enclosure to prevent damage to sensitive components. These environments include, but are not limited to, outdoor locations in warmer climates, manufacturing plants with dust or heavy particulates, corrosive atmospheres found in wastewater treatment facilities, and hazardous locations involving oil or explosive chemicals. In these scenarios, it is better to use sealed enclosures with integrated closed-loop cooling. Closed-loop cooling devices consist of two separate circulation systems in a single unit. One system – sealed against the ambient air – cools and recirculates clean air throughout the enclosure. The second system uses ambient air or water to remove and discharge the heat. Closed-loop cooling systems maintain the optimal temperature while keeping out warmer ambient air, moisture, and airborne contaminants.
For a more comprehensive explanation of open- and closed-loop cooling, we invite you to read our free whitepaper, Increasing the Lifespan and Reliability of Electronic Components (page 5). If you have questions, contact an Enclosure Cooling Specialist for expert guidance or help with finding the right solution for your thermal management requirements today!
