Review (November 2008)
By Kevin Nakano
The power density of components found in today's electronics keeps temperatures high, especially among those stored in tight quarters. For example, our Denon AVR-5308CI has seven 150-watt THX-certified power amplifiers in a single chassis. The challenge is to keep these components cool enough to be reliable for years to come. Ignoring this can drasticallly shorten the life of the internal electrical components due to thermal stress. To address this, a company called Active Thermal Management (ATM) has introduced several products that offer solutions for both cabinets (Enclosure Coolers) as well as for individual components (Equipment Coolers). We will cover the Cool-it II product, which is designed to keep a component cool by blowing air into the top of the chassis. This cooling system sits on top of the component and requires that there be some ventilation around the unit. It is ideal for components that have limited ventilation and localized heat buildup. This particular model will not be effective in a sealed enclosure simply because the hot air will just circulate as opposed to bringing in cooler air into the chassis.
The Cool-it II runs very quietly thanks to the design that limits the voltage to the dual 120mm brushless DC fans. These fans are rated at 12VDC, but only run at a mere 6.5VDC due to the 22 ohm power resistor installed in series with the voltage from the power adapter. The result is a very low noise level of only 19dBA. The Cool-it II only has an ON and OFF mode and does not throttle the fans at different speeds. The transformer-based power adapter is rated for 9VDC at 0.5 amps. The Cool-it II has an inline power connector that makes it easy to disconnect from the bulky power adapter. The unit measures only 15.75" wide x 6.75" deep x 2 1/8 high.
We installed the Cool-it II on the top of our Denon AVR-5308CI THX receiver inside of our StudioTech Ultra U-22T cabinet. Normally this receiver has pretty good ventilation thanks to the large vents on the chassis. However, due to the lower impedance of our M&K speakers connected to the receiver, the unit runs hotter than normal. This is where the cooling system helps keep our electronics in check. The fans on the Cool-it II have 1-inch stand-offs that provide an air gap between the fans and the top housing plate. This allows air to move in from the sides and down into the unit. The fans sit flush on top of the unit it is cooling. The design works well and moves a good amount of air into the chassis. Since the design uses a thermal sensor to turn the fans on, there is no need to switch power to the cooling system. It can stay plugged in and runs only when needed.
More Air Flow?
- Kevin Nakano
Mitsubishi HC5500 1080p LCD Projector
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