Any thoughts on what’s the number one problem with home theater components? If you didn’t say heat build up, don’t be surprised because few seem to realize just how problematic inadequate venting can be. Not only can this lead to a serious degradation in the performance of the component, but it can also affect its longevity. Manufacturers “assume” their product will be used on a shelf all by itself with plenty of air moving around it, but in the real world components are often grouped together or placed inside of cabinets bereft of ventilation. And when you consider today’s modern 7.1 channel surround amplifiers, or devices like DVR/Tuners that run 24/7, the heat being generated can be significant. These components can cook anything mounted directly above and below it. And remember this: products with built-in fans are dispersing heat to everything around it.
According to Frank Federman, CEO of Active Thermal Management, the heat generated from a rise in the surrounding temperature (going from 70- to 88 degrees) can have a detrimental effect upon semiconductor life. “Electrolytic capacitors, used throughout all types of A/V gear, dry out and lose their ability to couple desired signals and filter out undesired hum and noise with excessive heat,” he says, adding that digital devices are especially prone to misbehavior and “locking up” when they overheat.
The Venting Solution
Cooling devices are the obvious solution. These products are designed for placement near the component’s vents. The purpose of the cooling system is to pull in cool air or push out hot air - keeping heat from building up around the component(s). The key to effective heat removal is having the airflow pass over and around the A/V components. A general rule, according to Federman, is to have the components lie along a line drawn between the point at which air enters the enclosure and the point at which it leaves the enclosure. Dividers and/or shelves present obstacles to this “straight-line” approach, so generous holes for air passage may be called for. Aside from seismic considerations (California readers take note), given reasonable ventilation, component placement within an enclosure is usually not critical.
Avoid placing heat-sensitive devices on red-hot amplifiers, but even that can be done if the right selection of cooling devices are employed. Active Thermal Management’s Cool-It II is a great option. It’s designed for placement above the heat sinks of a component (such as an amplifier), and directs a stream of cool air down to lower the temperature (Active also has models that blow air up, such as the Cool-Sat, for use under devices like satellite receivers). They also have the Dual-Mode Component Cooler, which not only cools but contains a “heat shielded” top shelf so that a component can be placed on it.
Heat build-up of a wall mounted Plasma or LCD HDTV can become an issue as well, especially when the TV is flush mounted in a wall. For this there’s Active’s Cool-Stick - designed thin enough for placement behind the set. It blows a steady stream of air and provides for a high degree of redundancy through sixteen fans, two power supplies and two thermal switches.
Back To Basics
Michael Robinson, CEO of Hometheatercooling.com has a few basic pointers for improving ventilation. “First, keep the air intake at the bottom of the cabinet and the exhaust fan near the top - this creates a natural chimney effect when equipment is in standby,” he says. Cable and/or DVR boxes should be placed on the top shelf, as this keeps them from acting like a hot plate for other components. Holes or open spaces in the shelves also help keep the air moving. From a cosmetic point of view, intake vents can be easily disguised with speaker cloth. Robinson cautions against venting to the outside of your house, as the warmth can attract unwanted animals and insects.
If you can vent via a rear panel, try the PQfan. It’s placed inside at the top of the cabinet, and blows air down and around before exiting. There are also systems which will pipe the heat out through flexible tubing such as the Active’s Cool-Stack II. And for those married to the room’s decor, there are venting systems available with unfinished wood grilles to allow for matching to fine wood cabinetry.
As has been seen, cooling devices can range from stand-alone for use with a single component to those devised to vent a “media closet” or even a dedicated room. Regardless, the benefits of venting will go a long way towards expanding the lifespan of your home theater equipment, along with helping it to work within the operating range that it was designed.
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