Both the Storm and Storm X Controllers can control fans as well. This board makes it easy to add fans to your lighting system, and it fully supports the fan control features of the Storm and Storm X. The board provides 12V through the included power adapter, and routes the control signals directly to where they're needed. In the absence of any control signal, the fan will go to its default state, which for most fans is ON. Supports 2, 3, and 4-pin PC fans, although control is only available for 4-pin fans. Here's a youtube video showing the hook-up procedure.
As of October 2016, this product comes fully assembled with no soldering required (previously it was a kit of parts that required soldering). A convenient solder jumper allows doubling up fans on a single control signal. Just bridge the solder pad on the bottom of the board to control two fans with one signal.