10 Enclosure Cooling Considerations

Components used in electronic and industrial equipment enclosures produce unwanted heat. This presents the problem of dissipating excess heat before it damages sensitive equipment. In some cases, the problem can be solved by ventilation – using simple air-moving devices such as enclosure fans or centrifugal blowers. However, in many applications, the ambient air surrounding the enclosure is contaminated or too warm to be used for the safe dissipation of any unwanted heat. Under these conditions, the life expectancy and performance of electronic components may be adversely impacted, often causing equipment slowdowns or malfunctions. For applications where ambient air cannot be used, a heat exchanger or enclosure air conditioner is the best choice.

In order to create the best environment for the application, an evaluation of the anticipated operating conditions and thermal requirements of the equipment (or system) must be completed. Here are 10 important questions to ask when considering an enclosure cooling solution.

Does the equipment/system require active cooling, or is spot cooling adequate?
Are there any components that are particularly sensitive to heat or other adverse conditions?
How much heat is produced within the enclosure?
What is the maximum temperature acceptable in the enclosure?
What are the average and maximum temperature ranges of the ambient air?
Is a specifically maintained temperature range required?
What is the particulate and moisture content of the ambient air?
Does the ambient air contain dirt, oil, corrosives, or other contaminants harmful to enclosure contents?
Where can cooling devices be mounted on the enclosure?
Do the contents inside the enclosure need to be isolated (by the use of a sealed enclosure) from the heat or contaminants in the ambient air?

After all of the application-specific factors are determined, a decision can be made about the type of ventilation or cabinet cooling required, and which equipment provides the most appropriate performance and cost-effective solution. A little time and effort spent early in the design process to choose the optimum cooling equipment can save a lot of trouble and expense later, as this would prevent the need to retrofit with proper thermal management devices in the field.

Fans

Enclosure cooling fans occupy minimal electrical cabinet space and will move a substantial volume of air where flow is virtually unimpeded. Packaged fans can be used for filtered panel or rack-mounted cooling in such applications.

Blowers

Centrifugal and radial blowers are designed to operate against higher static pressures. Packaged blowers provide compact, filtered, rack-mounted cooling in a variety of airflow configurations.

Air Conditioners & Heat Exchangers

In applications where equipment operating temperatures must remain near or below that of the surrounding ambient air, or where airborne contaminants pose a threat to electronic components, the enclosure interior must be isolated from the external environment. For such applications, a heat exchanger or closed-loop air conditioning unit is required.