Dan´s Data has posted a review on 2COOLPC ducted fans for computer cooling. Here a snip:
The fan´s a 92mm square unit. Some computers use 92mm case fans, but most have the smaller standard 80mm units. All things being equal - just scaling all of the dimensions up and assuming the same rotational speed - a 92mm fan can be expected to shift about 30% more air than an 80mm one. All things aren´t necessarily equal, though; if the bigger fan has the same motor then it´ll spin slower, and have a smaller airflow advantage. Bigger´s still better, though.Read more
The fans are standard 12 volt units, and you plug them into your power supply with an ordinary four pin Molex plug-to-socket passthrough cable. So you don´t need to have a spare connector.
The plain $US24.95 2COOLPC has a sleeve-bearing fan rated at 42 cubic feet per minute (CFM) air flow; the PLUS version has a ball bearing one rated at 50 CFM. These ratings are free-air figures, not taking into account the obstruction value of the duct, but unlike airflow figures for regular case fans or CPU coolers, the 2COOLPC fans don´t have a lot of obstructions to blow air through and so probably perform pretty close to their specification.
