Hot-running notebooks have been the bane of portable computing almost since the technology's inception. Fortunately, notebook coolers are available to wick away some of the excess heat that threatens both your lap and your laptop, and the USB-powered Zalman ZM-NC1500 ($39.90) is the best of the bunch. This device has two powerful fans that offer the most effective cooling we've seen, along with adjustable speeds and a rock-solid, ergonomic design for a reasonable price.
Design and Aesthetics
Measuring 13.6 x 11.8 x 2.0 inches and weighing 1.8 pounds, the ZM-NC1500 is a bit bulkier and heavier than the 1.0-pound, 12.0 x 7.1 x 0.7-inch iHome IH-A706CW ($29.99) and the 0.8-pound, 12.5 x 6.3 x 1.2-inch StarTech USB Powered Laptop Cooler ($24.99), but with the added size comes a wider base that better accommodates larger notebooks than its rivals (it's designed for notebooks up to 17 inches in size). The 15.6-inch Acer Aspire 5738PG fit squarely on the cooler; it slid about a bit when placed on iHome's offering. Overall, this design feels sturdier than the competition, so the $10 premium is justified.
The face of the ZM-NC1500 features a grille that lets air from the cooler's twin fans blow up to the bottom of the notebook. When placed at the highest setting, the fan noise is substantial (it's noticeably louder than the IH-A706CW and StarTech cooler), but not overly distracting. The bottom of the cooler features a glossy black finish that attracts many fingerprints and smudges, but due to their location, the smears won't be of much consequence.
A scant two USB ports (one of which is used with the included cable to attach to a notebook) are located on the back of the device, as well as a power button, a power indicator LED, and a dial that controls fan speed. The cooler also has a pair of non-adjustable legs that boost the notebook into prime typing position.
To test the ZM-NC1500's ability to prevent overheating, we measured the heat radiating from the Acer Aspire 5738PG (immediately after being powered on) with a temperature gun in several hotspots: the bottom, the touchpad, the lid, and between the G and H keys. We saw readings of 82.0, 78.0, 76.5, and 79.5 degrees Fahrenheit, respectively. We then fired up a digital copy of Smokin' Aces and let it play for 15 minutes, with the notebook's brightness and volume at 50 percent. Afterward, we whipped out the temperature gun and measured temperatures of 97.0, 87.0, 78.0, and 91.5 degrees--an average heat increase of 9.4 degrees.
We let the notebook cool down for 45 minutes, and then once again fired up Smokin' Aces, this time with the ZM-NC1500 turned on at maximum fan speed. The fans didn't make much of a difference when it came to lowering the heat generated by the space between the G and H keys, touchpad, and lid (90.5, 86.0, 77.5 degrees), but the bottom of the machine dropped 10 degrees to a very comfortable 87.0. Overall, it held the heat increase to an average of 6.3 degrees, which was more effective than the iHome IH-A706CW (7.3 degrees) and the StarTech cooler (6.9 degrees), as well as a passive cooler (8.4 degrees).
After letting the notebook cool down to its base temperature, we then converted a 115MB MPEG-4 file to AVI while compressing a 4.97GB folder of mixed media. Temperatures were on a par with the ones seen while watching a movie (97.0, 87.0, 78.0, 91.5 degrees), and when we performed the same actions with the Zalman's fan activated, we saw cooler temperatures (85.0, 83.5, 75.0, 90.0 degrees). Once again, it was the best at cooling, holding the average heat increase to just 4.4 degrees--the same as the IH-A706CW (4.4 degrees), and much better than the StarTech cooler (5.8 degrees) and passive cooler (6.1 degrees).
The Zalman ZM-NC1500 is pricier and a tad louder than its competitors, but it executes its purpose--cooling a hot notebook--with aplomb. For $39.90 we would've liked more than a single available USB port for hooking up other gear (the $29.99 iHome IH-A706CW has three extra ports), but this accessory offers the best performance and build quality in its class.