Efficiency of DC ceiling fans?
 

Have been see in a lot of talk about the energy savings of ceiling fans with DC motors. Do they really save that much electricity or is it spin?

ECM is a lot more efficient than induction for multi speed fan motors. The very nature of making an induction motor multi speed (without an inverter) greatly drops efficiency.

Read this:

http://www.fsec.ucf.edu/en/publicati...cr-1770-98.pdf

Pretty sure those values are for shaded pole motors. Even the cheap PSC motors do a lot better than 12%, maybe 60% for a bad one. In contrast, ECM easily does 80% or more.

I'm just sayin' the average $50 ceiling fan is not real efficient. A $180 Brushless DC model might use a third of the power at the same speed. The flat, oar-shaped blades don't help out either. That being said, ceiling fans don't use that much power unless you don't turn them off when you leave the area. A fan not running uses no energy.

Interesting discussion as we have several ceiling fans that are on a LOT in the summer. I had honestly not thought of the DC motor fans as that much more efficient. Dumb me as I am certainly aware of the impact DC motors have on furnace fan performance.

Now to the point - which specific ECM ceiling fans are the best buy? I need to buy a new one.

Steve

296 CFM per watt, but fan will set you back $300. Really would like to see LED light kit as an option on this.

Maybe it's possible to DIY a ceiling fan out of an ECM HVAC motor and a condenser fan blade? Probably won't be particularly cheap unless you can get a "bad" motor and repair it...

Would fail the WAF test. Wouldn't be the safest thing in the world either.