Fan Speed Control

I have several fans controlled by PWM. One of them is a Surflo product (similar to the FF) that is no longer manufactured. It has brushes but has run flawlessly for years and move tons of air. I installed the original version of the Heng's Vortex in the bathroom, then added a PWM to it. It really moves a lot of air, but can get noisy (wind noise) at top speed. I also have a fan that is intended for the windshield area of a motorhome, but I use it for the bed area. I added a 12.5 khz PWM controller to it that works excellently with no noise that I can hear. The Surflo fan has the highest draw at 2.1 amps on full speed. I'm a firm believer in this technology. It's worked great for me. It's awesome to be able to select virtually any speed you want.