Summary: I've used Zalman fans for years and this was the first that failed me in such a spectacular manner. I do intend to buy more of these, but will make sure to keep batteries in my Smoke Detector fresh.
Pros: I have bought about a dozen of these and have had them running for about a year now in various builds. Cheap, reliable, and quiet.... except for one out of the 12.
Cons: One of the 12 fans seized up and nearly caught on fire, filling the entire room with acrid smoke. Thankfully I was in the room at the time and was able to shut down the machine (yanked power cord) before the fan actually melted. Bearing and circuit board on fan was cooked with no warning signs of failure. Made a loud noise for about 10 seconds then started smoking.
Summary: My last computer case fan, 120mm in size, capable of moving a 64cfm of air at 22db was produced by a brand-x company. The brand-x product had an inherent design flaw causing it to explode during normal operation. This happened to me and I will no longer purchase brand-x products.
Pros: Its a fan. It makes air move in one direction. It did not explode when powered up.
Summary: I have to wonder if this is a common issue with Zalman fans. I used to have a Zalman ZF700 graphics card cooler with a fan that made the same kind of noise (and a replacement part did the same thing). It's a shame to see little has changed in their fans in 7-8 years.
Pros: As long as you only use these fans in a vertical orientation, these appear to work well. They're one of the few fans on the market at this price point with a motor that doesn't make an electrical clattering noise when running. In addition, the fan itself is very quiet below 1,000 RPM. Other fans produce a noticeable buzzing noise all the way down to 700 RPM, but this one doesn't. These have fairly long cables, so no worries if your motherboard has poorly thought out f...
Cons: These fans have cheap bearings that make an obnoxious hissing/scraping noise when placed in a horizontal orientation, such as the top of a case. It happens at all speeds, but becomes very apparent below 1,000 RPM. No other fan I've used does this, no matter what bearing type. I found this to be unacceptable, so back to the seller it goes.