Electronics Protection - Summer 2016 - (Page 12)

Feature Cool it Your Way: Versatile Cooling for Electronics Enclosures Justin Moll, Vice President, US Market Development Pixus Technologies Electronics enclosures are used in countless test/analytics/measurement devices for multiple end markets. This includes various instrument systems in Oil & Gas, industrial and power control, medical, lab/test and military designs. The end applications are too numerous to name. But, serving all of these types of devices requires a wealth of cooling options for instrument cases. There are a wide range of cooling options to consider for sheet metal and aluminum enclosures: incorporating fans, partial top perforation for heat exhaust, full top perforation for higher exhaust requirements, bottom and top perforation (often for external fan trays or other cooling, and front and/or rear panel perforation in various types. We'll leave out the more exotic other options for cooling that include liquid, conduction-hybrids, etc. Now consider a line of modular enclosures. To provide standard aluminum enclosures in 1U to 14U heights, widths at 19 or 9.5 inches, or compact sizes, and depths from 250 mm to more than 500 mm, there are a lot of configurations. Providing every one of the above cooling options is not always available standard in every size, but customization can typically be kept to an absolute minimum. That means a standard or "modified standard" tailored enclosure solution that gets to market quickly and keeps development and production Figure 1. There are various costs low. Figure 1a shows a top perforated cover on an enclosure for natural convection, Fig 1b for top and bottom airflow, and Fig 1c for perforations in the top, bottom, and rear of the instrument case. Clearly, more openings allow more heat evacuation. Many of today's instruments and devices that use metal enclosures have an internal fan on a device and/or another cooling option such as using heat sinks/conduction. Of course, completely enclosed options are available too. However, placing a fan tray at the bottom of the enclosure is another common option. Alternatively, fans can be incorporated into the rear (typically) panel. Often, these are standard 120 mm muffin fans, but other sizes are certainly possible. See Figure 2 for an example. For access into the enclosure, it is common for these panels to be hinged on the side or the bottom. This allows for maintenance or replacement of parts and general access to the device. Feet and Stands for More Airflow Many desktop enclosures come with standard "feet" options. These are not just aesthetics. The feet can help angle the enclosure for easier viewing, prevent scratches on the desktop, and provide spacing between the bottom of the enclosure and the desk/surface to allow airflow. (See Figure 3) The carry handle could also act as a stand to prop up the enclosure and achieve these same goals. The dual function is very convenient for devices that need to be transported often. It also provides a nice aesthetic appearance. Instead of standard feet, there are stands that help attain the same goal. These end caps also provide a stand-off and protect a desktop or lab bench from direct contact from the metal case. The enclosure in Figure 4 shows how a clever design allows multiple enclosures to be stacked. The top of the enclosure has a shape on the edge of the bezel that allows a similar enclosure placed above it to securely fit. 12 Summer 2016 * www.ElectronicsProtectionMagazine.com perforation options for venting of enclosures. Fig 1a) top venting. Fig 1b) top and bottom venting. Fig 1c) top, bottom and rear venting Figure 2. Incorporating rear evacuative fans does not require customization. Rear panels with fans cutouts are not uncommon. Figure 3. Enclosure feet have benefits, including angling, bottom venting for cooling, and protecting surfaces from scratches. http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - Summer 2016

Electronics Protection - Summer 2016
Contents
Editor's Choice
Common Coolant Types and Their Uses in Liquid Cooling Systems
The Benefits of Vertical Integration for Customized EMI Shielding Products and Services
Cool It Your Way: Versatile Cooling for Electronics Enclosure
Heat Pipes and Vapor Chambers – What’s the Difference?
Securing Electronics in Modern Railway Systems
Enclosures
Thermal
Power
Hardware
Industry News
Calendar of Events

Electronics Protection - Summer 2016