Efficient but quiet: Lead to great effects with a diameter of 4 inches, speed of 2930 RPM and 100 CFM air flow ... Note: Please turn the fan off immediately if the blades get stuck by other ...

There are three types of boosters. The simplest is a fan unit that sits on top of the register. Another option is an in-line fan that you can install in the duct line. The third type, shown here ...