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US Ceiling Fan Efficiency Rule Proposal

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PwrElectronics:
Apparently, there is some proposal from US DOE on ceiling fan efficiency that has gotten some political going much like the gas stoves thing a while ago.

One can find all sorts politically related article about it that are not the point of this post, but none actually get into what technically would change to get this supposed efficiency improvement.

I finally found this article that goes into fans would have to change from AC to DC motors.  To me, that means a circuit board and the fan is no longer a "passive" device.

https://www.lightnowblog.com/2023/06/us-doe-proposes-new-ceiling-fan-efficiency-standards/

Like a lot of other modern items that claim to save energy, the downside is reduced reliability when that control board fails.

I bought some LED fixtures for a room remodel and one of them failed with very low hours on it.  I opened it up to find a film cap on the power supply blown up.  Will see if I can fix it as I don't think that style fixture is made anymore 3yrs later.

Not sure why this comes up again now, it seems that there were proposals like this in 2013 as well.  Maybe it did not pass and this is another attempt.

NiHaoMike:
I think ceiling fans can get a lot more efficient merely by using a motor which is optimized for a single speed with low slip, the way multiple speeds is usually done is an ugly hack. And if BLDC ceiling fans become common, there likely would be a lot of generic driver boards for them like how there are a lot of generic ESCs for R/C motors.

joeqsmith:
Many many years ago, I was working on a project to make a quite ceiling fan controller.  In place of the typical SCR phase control, I was PWMing a MOSFET with a full wave rectifier.  The PWM frequency was just above the audio range.  No more buzzing fans....

Of course, 20' of wire and a fair bit of power make for a good radio station, much like the crap LED lights I see coming out of China.  Maybe today I could have gotten away with creating such splatter. 

BrokenYugo:
Read the article, go look at currently offered fans, this proposal only really looks to really apply (like double the efficiency) to larger fans, 53 inches on up, seems 52 is the popular "large" at the moment based on what's stocked locally.

I wouldn't worry about it, remain calm, the sky is NOT falling.

schmitt trigger:

--- Quote from: joeqsmith on September 02, 2023, 02:02:49 pm ---Many many years ago, I was working on a project to make a quite ceiling fan controller.  In place of the typical SCR phase control, I was PWMing a MOSFET with a full wave rectifier.  The PWM frequency was just above the audio range.  No more buzzing fans....


--- End quote ---

Funny that you mention it, yesterday I stumbled upon an old Motorola Semi app note, which described exactly what you mentioned. The objective of the app note was to promote the features of a microcontroller family.
No word on RFI issues, though.

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