A cool way to keep a laptop from breaking a sweat

Overheating can be a big problem for laptop PCs. It prevents the computer from operating at optimal efficiency and, in some cases, will cause the laptop to crash.

In fact, heat is the No. 1 enemy of most electronics. And it is even more dangerous in small devices, such as netbooks, because so little space can be devoted to dissipating that heat. And, of course, there is the discomfort of having a really hot laptop sitting on your legs, which might even get to dangerous levels.

ThermaPAK HeatShift Laptop Cooler 17"

Pros: No moving parts to break.
Cons: Heat eventually builds up during constant use.
Performance: B+
Ease of Use: A+
Features: B
Value: A-
Price: $35

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Every laptop user has likely seen at least one ad for a laptop cooling pad. The question that immediately comes to mind is: Does it really work? Will this little $20 or $30 device actually help my laptop run better, or is it just another peripheral gizmo that is all show and no go, the equivalent of computer snake oil? It’s questions like those that keep those of us in the lab up at night. So, to help us sleep, we decided to test one.

Laptop cooling pads come in two varieties. Active pads have fans that aid cooling by producing extra airflow on the bottom of a laptop. These have a few disadvantages. First, they require power through a USB connection or separate power cord. And if they are pulling power from your battery, that means less runtime. Second, more moving parts means more chances of something breaking.

In contrast, most passive coolers use substances that draw heat away from a computer by being physically in contact with it, a method of heat transfer called conduction. These coolers require no power, but sometimes the heat transfer can be less effective if the heat source is not evenly dispersed across its surface.

We decided to test the second type of cooler because they are generally less expensive and you can toss one into a laptop bag without regard for the safety of the unit, which is mostly just cloth around a heat-absorbing substance. And it probably won’t give your friendly Transportation Security Administration folks any cause for alarm either.

The HeatShift Laptop Cooler from ThermaPAK is one of those types of pads with no moving parts. But it alleviates many of the potential problems of passive coolers and does an effective job of cooling down a laptop PC.

The side of the pad that would rest on your legs is soft to the touch and prevents stored heat from coming through. It can easily fit in a laptop case because it is only a half-inch thick. It is flexible and can be folded or rolled to fit into any piece of luggage. We tested the 17-inch model, which is just big enough to hold a laptop with a 17-inch display, though it’s a bit of overkill for smaller computers.

The key to this device’s success is what lies between the cloth sheets. The pad has salt crystals inside that draw heat away from a laptop. As they do, they melt into a gel that moves heat through it, because liquids generally can absorb more heat than comparable solids, and the melting point of the salts is very low. At this point, the heat transfer stops being conduction — solids touching — and starts being convection, which is movement of liquid molecules.

That means that even if one spot is exposed to more heat than the rest, it will still transfer that heat to the rest of the pad. We tested this by applying a concentrated amount of heat to one corner of the pad. Eventually, the entire inside of the pad turned to gel as the heat moved through it.

Nothing gets a laptop PC heated up faster than taxing the graphics accelerator, so that is exactly what we did. We ran some high-end programs that use extensive amounts of 3-D graphics and noted the points when performance slowed. One time, the laptop locked up entirely. Then, after everything cooled down, we ran the same programs with the laptop resting on a HeatShift pad.

We were pleased that the pad kept the laptop noticeably cooler to the touch when we used the HeatShift. Even more important, the points when slowdowns occurred were much later, and the laptop never locked up. The results are conclusive: The HeatShift Laptop Cooler works.

The only drawback we found was that this product has a finite limit to the amount of time it works because there are no moving parts and eventually convection reaches a point of rapidly diminishing returns. If the pad is drawing heat constantly, it will continue to do so until every last solid crystal is turned to gel. At that point, there is essentially nowhere for heat to go, and it will stay that way until the heat source is taken away.

However, we never achieved that state with several hours of normal laptop use and could only get there using some of our rugged test gear to really heat things up. Even on the longest flight we could imagine with a huge heat-producing laptop, you would probably be fine in terms of extra cooling protection. It’s definitely not snake oil.

ThermaPAK is selling the HeatShift Laptop Cooler 17" in a variety of colors for $35. That is a good price for something that can make your $500-plus laptop work better and last longer. And that’s pretty cool.

ThermaPAK, www.thermapak.com