Re: fantastic fan vs maxxair and bathroom fan replacement Reply #25 – September 06, 2020, 01:23:06 pm Quote from: Jay Carlson - September 04, 2020, 03:05:06 am I almost never run the fans on any but lowest speed unless smoke alarms going off from cooking. I question if they really move that much more air on higher speeds (mine all have covers which may limit air flow a bit). Not sure how big of a deal the wasteful speed control resister thing is, but the idea of running even much slower with a PWM controller sounds appealing, though I may never get around to it and it sounds potentially more failure prone.Raising the vent covers up a 1/2" or more, by stacking washers on the mounts, will provide more airflow.Sleeping in the bunk on hot summer nights, we often have both FF fans on high, providing a lot of cooling airflow through the escape hatch. The same can be done by opening the bunk's side windows.Newer FF fans have PWM controllers, older models can be converted with aftermarket PWN controllers.This is what was used for one of our FF fans and a fan in the bunkAmazon.com : KEDSUM® PWM DC Converter 12V-36V 10A DC Motor Speed Controller...When the fans are operated at low speeds, the PWM controller saves a significant amount of power, compared to using resistors to provide low speeds. Both controllers have been in use for several years without failure.Larry 1 Likes As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.