Thermal management can save you money

Wednesday, January 1, 2003

In her article, “Digital Products Proliferate, Assimilate in Security Market,” which appeared in the September 2002 issue of Security Systems News, Joanne Friedrick accurately cited the increasing use of digital technology in security applications.

The proliferation of this technology necessitates that those specifying and installing the equipment take into account new considerations in how it is integrated – specifically in terms of thermal and cable management within surveillance and monitoring consoles and rack enclosures.

These are issues that have largely remained footnotes in security installations, but as anyone who has had a DVR shut down because it overheated or has had to navigate an incomprehensible maze of cables in order to access the rear panel of a piece of equipment can testify, effective thermal and cable management can save a great deal of time, money and heartache when installing and maintaining security systems.

First and foremost, good thermal management within a console or rack will help save money in routine maintenance and extend the life cycle of your equipment. Consider this: for every increase of 10°F above 85°F, long-term electronics reliability is reduced by 40 percent. By maintaining optimum temperatures within a console or rack enclosure, not only are you extending the life of the equipment inside, you are also cutting down on the time and money spent on maintenance and service calls.

Thermal management methods fall into one of two general categories: active and passive. An active thermal management system uses a combination of fan(s) and vents to aid in the constant flow of air through a console or rack. On the most basic level, vents in the bottom of a console or rack take in air from the outside, which is then forced through the unit and out by an exhaust fan mounted near the top. This ensures a steady flow of air through the unit.

The life of your fan itself can also be extended by using it in conjunction with a proportional thermostatic fan speed control circuit, a device that regulates the fan speed in proportion to the internal temperature of the console or rack enclosure. The faster a fan runs, the faster it wears out; these devices will help maximize its longevity.

Alternatively, a passive thermal management system utilizes a combination of vent placement and the natural powers of convection to maintain air circulation through consoles and racks. Like an active system, a passive system intakes air from the outside through vents located in the bottom of the unit but, instead of using top-mounted fans to force airflow, vents placed in the top allow the warmer air to naturally rise up and out of the console or rack.

Because digital technology has lead to the development of equipment that is typically smaller in size than its analog counterparts, the number of components that can be mounted within a single console or rack has increased. This means that not only is equipment density greater, but the amount of cable running through a single unit has increased as well, bringing to light the importance of how that cable is managed.

When used properly, integral lacing points strategically located throughout a console or rack should prevent cable from interfering with access to rear equipment panels. To complement built-in lacing points, adequate facilities should be incorporated within a unit to accommodate the addition of cable lacing bars when necessary, and provisions should also be available for cable to enter/exit a console or rack. These simple yet essential features make routine maintenance easier and more efficient and greatly simplify the process of switching equipment in and out of a console or rack.

As the security industry continues to enjoy the efficiencies now offered by the growing presence of digital technology in all facets of our business, those of us who not only specify and install the equipment, but who design and build it as well, should maintain thermal and cable management as an important role in the process. This will help deliver a final product that is reliable, easy to maintain, and of benefit to the end user for a long time to come.

Bob Schluter is president and chief engineer of Middle Atlantic Products Inc., a manufacturer of steel enclosure systems for a wide range of applications, including the security, commercial audio video, broadcast, post production, structured cabling and premise wiring markets.