How to Design Natural Convection Cooling Inside Electronic Enclosures

Electronic enclosures protect sensitive circuit board components.

Electronics are found in the most simple and complex devices, from a basic garage door opener to a business server computer system. All electronics use printed circuit boards (PCBs), holding small and large components, within an electronic enclosure or assembly. These components generate heat as they function for the device. Unfortunately, heat directly affects the electronic functioning and higher temperatures will reduce the components' lifespan. As a result, electronics engineers must create adequate airflow, called natural convection, through the device for regulating excessive heat levels.

Things You'll Need

• Printed circuit board
• Electronic enclosure
• Screen
• Louvers

Instructions

1. Increase the spacing between the enclosure's top and the components below. Heat rises naturally, even in a compact space. Designing an electronic enclosure with ample top space allows the majority of the heat to rise away from the working components, keeping them cooler during operation.

2. Expand the area between each individual component. Modern technology normally boasts complex electronic operations within a small package, but densely packed components generate a lot of heat. Natural convection depends upon an unimpeded airflow through the enclosure and between components. Enlarging the gaps between components will keep the entire device cooler.

3. Install venting at the top and bottom of an electronic enclosure. The venting encourages airflow, much like opening the flue in a chimney. Air moves from the bottom vent to the top vent, pulling heated air away from the components.

4. Install screens or louvers across any opening into the device. Dust and debris that enters the device tends to settle on components, especially since there normally is a small magnetic force surrounding the individual modules. Over time, debris accumulation creates a blanket around components, heating them up. Screens, matched with adequate natural convection, will ensure cooler component operation.

Tips & Warnings

• Natural convection does not work for all electronic designs. Devices that generate a lot of heat, such as computers, must have a fan or air-conditioning module to help alleviate heat. Components easily will fail under excessively heated conditions.

References

• Process Cooling: Heat + Humidity = Hazard
• Bud Industries, Inc.: Enclosure Design Tips Handbook