Author Topic: US Ceiling Fan Efficiency Rule Proposal  (Read 6709 times)

0 Members and 1 Guest are viewing this topic.

Offline PwrElectronicsTopic starter

  • Regular Contributor
  • *
  • Posts: 107
  • Country: us
US Ceiling Fan Efficiency Rule Proposal
« on: September 02, 2023, 01:23:16 pm »
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.
 

Online NiHaoMike

  • Super Contributor
  • ***
  • Posts: 9323
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #1 on: September 02, 2023, 01:53:05 pm »
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.
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Cryptocurrency lesson 0: Altcoins and Bitcoin are not the same thing.
 

Offline joeqsmith

  • Super Contributor
  • ***
  • Posts: 12280
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #2 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....

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. 

Offline BrokenYugo

  • Super Contributor
  • ***
  • Posts: 1214
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #3 on: September 02, 2023, 02:14:08 pm »
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.
 

Offline schmitt trigger

  • Super Contributor
  • ***
  • Posts: 2431
  • Country: mx
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #4 on: September 02, 2023, 02:25:44 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....


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.
 

Online ejeffrey

  • Super Contributor
  • ***
  • Posts: 4034
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #5 on: September 02, 2023, 05:07:25 pm »
I have a few brushless DC ceiling fans and they are fantastic.  I wouldn't buy another AC fan if I could avoid it, just for the noise difference.  I'm not sure about long term reliability as I've only had they for  about 5 years but I don't really see a reason why a BLDC controller needs to be particularly failure prone.

The upfront cost used to be a fair bit more but I think has come down as they became more common and not just a luxury product.  Even when more expensive if they are used a lot they will probably pay for the difference in a few years.
 
The following users thanked this post: Someone, thm_w

Offline TimNJ

  • Super Contributor
  • ***
  • Posts: 1720
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #6 on: September 02, 2023, 10:33:04 pm »
I was thinking about this the other day. I have a pedestal fan (~12” blade diameter) which works well but is rated at 45W! (And quite hot too…which is kind of funny considering the intended purpose.) 45W is still at least an order of magnitude lower power consumption than a window A/C unit, but still rather high considering it’s just a fan with modest airflow.

The obvious issue is the shaded-pole motor. Might be around 30% efficient or so? Permanent split capacitor (PSC) should be at least twice as efficient I think, but (usually?) larger due to the capacitor. Plus more expensive.

I’d guess that a brushless solution can come out cheaper compared to a PSC motor, due to smaller size/less raw material, although it possibly evens out with the addition of the control circuit. Of course, like anything, a robust (long lasting) mains powered BLDC fan can be designed, but it will be hard to avoid the inevitable race to the bottom. At least to consider mains transients, BLDC fans should need to pass the equivalent of CISPR35 immunity requirements. That might be about as close to enforcing a “reliability” standard as you can get.

Are ceiling fan motors traditionally shaded pole? PSC? Something else?

 

Online bdunham7

  • Super Contributor
  • ***
  • Posts: 8178
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #7 on: September 02, 2023, 10:41:57 pm »
Are ceiling fan motors traditionally shaded pole? PSC? Something else?

The most common setup I know of is a many-pole PSC induction motor.  I think the one I'm under right now is 18-pole, so it's natural speed is 400RPM.  The ones with a 3-speed switch use capacitive dropping, mine uses a separate variable-speed controller that I presume is some sort of PWM, unless it switches in a lot of small capacitors somehow.  This one is totally quiet, B/T/W, although some ceiling fans do hum a bit.  I don't think they are all that inefficient and they are inexpensive.  I'm going to guess there is a premier ceiling fan manufacturer behind this legislation. 
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 
The following users thanked this post: TimNJ

Offline Stray Electron

  • Super Contributor
  • ***
  • Posts: 2253
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #8 on: September 03, 2023, 01:24:28 am »
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.


   See the highlighted portion.  That's my problem with all of these so called "energy-saving" requirements.  The reality is that the engineering, design and quality control behind the products is so poor that none of them live up to the claimed potential savings due to their poor reliability and short life times.

    If the US Gov or any other Gov actually wanted to save energy then they should MANDATE the life span of these over-priced "energy saving" products.

   But one other point, the "proposed" requirement doesn't actually say that DC motors would be required.  That is just the opinion of the author. 
 
The following users thanked this post: tooki, MrMobodies, RJSV

Offline jonpaul

  • Super Contributor
  • ***
  • Posts: 3656
  • Country: fr
  • Analog, magnetics, Power, HV, Audio, Cinema
    • IEEE Spectrum
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #9 on: September 03, 2023, 01:57:31 am »
Check % total US energy:

US govermnet
US military
Industrey, commerce, transport

Residential homes
commercial real estate

The fans are perhaps 10 e -6 of totoal

Now compare US/EU/
vs China/India  total energy

If biden  suceeded 9magically)  to reduce all US energy to zero, China and India will continue to use hughe  coal, oil nat gas


Real solution is nuclear and fusion, nor political theater, in EU or US

Just the ramblings of an old retired EE.

Jon
An Internet Dinosaur...
 
The following users thanked this post: 2N3055, RJSV, .RC.

Online bdunham7

  • Super Contributor
  • ***
  • Posts: 8178
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #10 on: September 03, 2023, 02:41:39 am »
   But one other point, the "proposed" requirement doesn't actually say that DC motors would be required.  That is just the opinion of the author.

From what I can see, the requirement seems to be pretty closely tailored to be achievable by certain current products but out of reach of others.  Even if you doubled the efficiency of a ceiling fan, is that a big deal?  Enough for me to take my very durable fan off my ceiling and spend 5X as much for the new one?  These things easily last several decades.
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Online coppercone2

  • Super Contributor
  • ***
  • Posts: 11341
  • Country: us
  • $
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #11 on: September 03, 2023, 02:51:26 am »
I think the government should make you buy a dyson air multiplier
 
The following users thanked this post: RJSV

Online ejeffrey

  • Super Contributor
  • ***
  • Posts: 4034
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #12 on: September 03, 2023, 04:46:40 am »
   But one other point, the "proposed" requirement doesn't actually say that DC motors would be required.  That is just the opinion of the author.

From what I can see, the requirement seems to be pretty closely tailored to be achievable by certain current products but out of reach of others.  Even if you doubled the efficiency of a ceiling fan, is that a big deal?  Enough for me to take my very durable fan off my ceiling and spend 5X as much for the new one?  These things easily last several decades.

Depends on how much you use it, but if you use it 24/7 for 6 months a year, the BLDC fan could save you $50+ / year at average US electricity prices.  That's not enough to make me want to throw out and replace a working fan, but it's easily enough that if I was buying a new fan I would pay a substantial premium for the more efficient unit.  Of course if you don't use it much the running costs are not that important.

Also, the cost difference is that much any more.  A few years ago, BLDC fans were mostly the domain of expensive "designer" brands.  And it still kind of is, but you can also get $150 BLDC fans from home depot.  At that point I'm not sure why you would want to buy a $120 fan with an AC induction motor.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20363
  • Country: gb
  • 0999
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #13 on: September 03, 2023, 10:16:06 am »
Whilst I'm all for greater energy efficiency, it does seem a little silly given the energy savings will be miniscule. I think they should try better labelling first. I'm sure many people would buy a more expensive fan if it's cheaper to run and quieter.
 

Offline Nominal Animal

  • Super Contributor
  • ***
  • Posts: 7198
  • Country: fi
    • My home page and email address
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #14 on: September 03, 2023, 10:51:52 am »
I am not in the US, but I do have a three-speed ceiling fan – I do believe it is a single-phase induction motor with three-part windings, with a direction switch – with a very wide (diameter almost 300mm) motor section.

I originally bought three of them over a decade ago, and I'm extremely happy with them still: the motor is absolutely silent.  I appreciate quiet.  It matters to me more than the energy consumption, so much so that I'm willing to pay for double the power use for a silent motor.  I do pay about 0.30 €/kWh for my electrical energy right now (including power, transmission, and taxes).

I only use the fan during the summer months, and then mostly at its lowest setting (about 50 RPM) to circulate the air.  The only noise it generates is the slight white noise from air drag at the blades; otherwise I could not use it in the same room I sleep in.  I have swapped out USB wall warts and power supplies that use too low (<25 kHz or so) switching frequency for me, causing a sound I can perceive when trying to fall asleep.  (It is also the reason why I've always built my own computer enclosures, as I do need essentially silent operation if I intend to sleep in the same room.)

BLDC motors can be absolutely silent, but I wonder if any manufacturer bothers to make one that is silent at very low RPMs?
When PWM-controlled 12V PC fans first came to market, they had a similar problem, too.  They do have a separate 12V power input, and their PWM input is standardized to use a 21-28 kHz PWM frequency – 25 kHz nominal – with minimum RPMs typically on the order of 300 RPM.  Thus, it is not difficult to filter the effects of the PWM out within the human hearing range (plus a bit above  for freaks like myself), it's just that 'cost optimization' tends to mean such niceties are omitted.

(When they tried to make compact fluorescent flickering horrible-CRI lights the standard here, I refused.  I only moved from glowing tungsten to LEDs when I found ones that did not irritate my vision even when I was tired.  I'm actually quite happy fluorescent tubes are being phased out.)

I fear this is just another race to the bottom, to the lowest common denominator.  Most people will end up with buzzing ultrasound generator fans, with only the very rich using custom-made "illegal" silent devices –– because when you cannot get any richer, you can still make others poorer, and that way make-believe yourself better than others.

>:(
« Last Edit: September 03, 2023, 10:54:06 am by Nominal Animal »
 

Online bdunham7

  • Super Contributor
  • ***
  • Posts: 8178
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #15 on: September 03, 2023, 06:27:55 pm »
Depends on how much you use it, but if you use it 24/7 for 6 months a year, the BLDC fan could save you $50+ / year at average US electricity prices. 

Also, the cost difference is that much any more.  A few years ago, BLDC fans were mostly the domain of expensive "designer" brands.  And it still kind of is, but you can also get $150 BLDC fans from home depot.  At that point I'm not sure why you would want to buy a $120 fan with an AC induction motor.

That would be an extreme use case--we use them quite a bit, but not that much and usually at low speeds.  I've never measured the power usage.

If the price drops enough to make them attractive, then I suppose we don't need legislation.  I didn't realize they were competitive now and at those prices, if they are quiet, reliable and have built-in speed control then that's what I'd probably buy...someday.  I did buy a fairly expensive BLDC attic exhaust fan, but there I did measure the energy used (it was a lot and all during peak times) and it made sense.  The increase performance and near total silence are just bonuses. 
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20363
  • Country: gb
  • 0999
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #16 on: September 03, 2023, 06:42:42 pm »
Lower speeds generally correlate with less noise and higher efficiency. It's better to have a larger fan, moving the same amount of air per second, at a lower velocity, than a tiny fan, spinning much more quickly. Unfortunately a larger fans is much more expensive to make, compared to a smaller one.
 

Offline Jeroen3

  • Super Contributor
  • ***
  • Posts: 4209
  • Country: nl
  • Embedded Engineer
    • jeroen3.nl
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #17 on: September 03, 2023, 07:16:10 pm »
Whilst I'm all for greater energy efficiency, it does seem a little silly given the energy savings will be miniscule. I think they should try better labelling first. I'm sure many people would buy a more expensive fan if it's cheaper to run and quieter.
Miniscule times 193 million (2007 data) is still a lot. Sometimes if the devices stop innovating you have to force them a bit.

You'd be amazed how little energy a fan can use with one of those low voltage dc phase motors. I have a big Duux fan that can run on a battery. Any equivalent ac shaded pole would humm, get hot and use >20W.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20363
  • Country: gb
  • 0999
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #18 on: September 03, 2023, 08:42:45 pm »
Whilst I'm all for greater energy efficiency, it does seem a little silly given the energy savings will be miniscule. I think they should try better labelling first. I'm sure many people would buy a more expensive fan if it's cheaper to run and quieter.
Miniscule times 193 million (2007 data) is still a lot. Sometimes if the devices stop innovating you have to force them a bit.
True, but in the US, there are far greater energy wasters than ceiling fans. Heck, they've only just banned incandescent lamps for general purpose lighting and their cars guzzle far more fuel than those in Europe do. I'm not bashing the US by any means. It just seems like a silly to do, when it's much easier to gain far greater energy savings.
 
The following users thanked this post: NiHaoMike

Online jpanhalt

  • Super Contributor
  • ***
  • Posts: 4005
  • Country: us
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #19 on: September 03, 2023, 09:29:30 pm »
Sorry to be late to the party.  Everyone who writes those regulations lives and works in air conditioned splendor.  Per day of operation, I find it hard to believe that an air conditioner uses less energy than a ceiling fan or more likely an attic fan in our South with an alternating current single speed motor.

I have lived for extended periods in Memphis, TN, Baltimore, MD, St. Louis, MO, and LA, CA without air conditioning.  The home I grew up in did not have AC.  Even in the 1970's, after my parents retired, their home had AC, but it wasn't run.  That home in LA was Spanish architecture with a tile roof.  AC was not needed.  In St. Louis and Memphis, we had attic fans.  It was perfectly comfortable.  My current home does not have AC, and as I write this, it is one of the hottest days of the year in Cleveland, OH.  I have a small fan.

Summer is for fun and warmth.  It would be great if American politicians could enjoy that instead on focusing on making everyone else miserable.  Show me a PWM'd DC fan that does not make noise.

« Last Edit: September 03, 2023, 09:31:26 pm by jpanhalt »
 

Offline Nominal Animal

  • Super Contributor
  • ***
  • Posts: 7198
  • Country: fi
    • My home page and email address
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #20 on: September 04, 2023, 05:56:56 am »
Lower speeds generally correlate with less noise and higher efficiency.
I've found that lower PWM duty cycles correlate with more noise, rather than less.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20363
  • Country: gb
  • 0999
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #21 on: September 04, 2023, 07:20:21 am »
Lower speeds generally correlate with less noise and higher efficiency.
I've found that lower PWM duty cycles correlate with more noise, rather than less.
I wasn't talking about PWM, but air speed i.e. velocity. Consider two fans, both moving the same amount of air per second. One is 2m in diameter and the other 200mm. The 200m fan will have to spin much faster, to move the same amount of air per second and therefore will make far more noise, than the 2m fan.
 

Offline Nominal Animal

  • Super Contributor
  • ***
  • Posts: 7198
  • Country: fi
    • My home page and email address
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #22 on: September 04, 2023, 08:18:59 am »
Lower speeds generally correlate with less noise and higher efficiency.
I've found that lower PWM duty cycles correlate with more noise, rather than less.
I wasn't talking about PWM, but air speed i.e. velocity. Consider two fans, both moving the same amount of air per second. One is 2m in diameter and the other 200mm. The 200m fan will have to spin much faster, to move the same amount of air per second and therefore will make far more noise, than the 2m fan.
Sure, but that's obvious. You must agree that because we're talking about the motor technology of ceiling fans, interjecting that larger fans are quieter than small fans, is a bit odd.

I was explicitly talking about the motor noise.   The diameter of my "silent" ceiling fan (blades) is about 48".  I did verify last night that even with my ear right below the center hub, there is no hum or even bearing noise, at the lowest (my preferred) speed of about 50 RPM; the noise from the blades is a nice white-ish noise with no overtones (it's too quiet to record with my phone or microphones I have, so no spectrum analysis).  I don't want to take it down and check the motor type, though.  The hub alone has a diameter of 10"-12", and I can see lots of coil wires through the cooling vents.  The only "downside" is that the lamp shades are Grandma-style flowery "roses", heh.

I am extremely aware of the difference the fan size makes for devices, as I have built and maintained racks of HPC nodes (1U with lots of fans), as well as my own "silent" PC workstation enclosures.  I was not referring to the size-dependent noise characteristics –– smaller fans having higher RPMs and therefore also higher acoustic spectrum peaks –– but to the effects of PWM'ing the BLDC motor in these fans, and to the "squeal" at low duty cycles at the PWM frequency due to insufficient filtering/smoothing in the motor.  (All PC fans, both three and four pin ones, are BLDC motors.  Three-pin ones are supply voltage controlled, typically 7V-12V, and four pin ones PWM controlled; some are hybrids which can be controlled either by voltage or by PWM.  Nowadays, many PC PWM fans have excellent noise characteristics, and the "squeal" is only an issue with el-cheapo ones; but it used to be an issue with basically all early PWM-controlled PC fans.  Just go look at old SilentPCReview stuff, for example.)
« Last Edit: September 04, 2023, 08:25:59 am by Nominal Animal »
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20363
  • Country: gb
  • 0999
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #23 on: September 04, 2023, 09:45:32 am »
Lower speeds generally correlate with less noise and higher efficiency.
I've found that lower PWM duty cycles correlate with more noise, rather than less.
I wasn't talking about PWM, but air speed i.e. velocity. Consider two fans, both moving the same amount of air per second. One is 2m in diameter and the other 200mm. The 200m fan will have to spin much faster, to move the same amount of air per second and therefore will make far more noise, than the 2m fan.
Sure, but that's obvious. You must agree that because we're talking about the motor technology of ceiling fans, interjecting that larger fans are quieter than small fans, is a bit odd.

I was explicitly talking about the motor noise.   The diameter of my "silent" ceiling fan (blades) is about 48".  I did verify last night that even with my ear right below the center hub, there is no hum or even bearing noise, at the lowest (my preferred) speed of about 50 RPM; the noise from the blades is a nice white-ish noise with no overtones (it's too quiet to record with my phone or microphones I have, so no spectrum analysis).  I don't want to take it down and check the motor type, though.  The hub alone has a diameter of 10"-12", and I can see lots of coil wires through the cooling vents.  The only "downside" is that the lamp shades are Grandma-style flowery "roses", heh.

I am extremely aware of the difference the fan size makes for devices, as I have built and maintained racks of HPC nodes (1U with lots of fans), as well as my own "silent" PC workstation enclosures.  I was not referring to the size-dependent noise characteristics –– smaller fans having higher RPMs and therefore also higher acoustic spectrum peaks –– but to the effects of PWM'ing the BLDC motor in these fans, and to the "squeal" at low duty cycles at the PWM frequency due to insufficient filtering/smoothing in the motor.  (All PC fans, both three and four pin ones, are BLDC motors.  Three-pin ones are supply voltage controlled, typically 7V-12V, and four pin ones PWM controlled; some are hybrids which can be controlled either by voltage or by PWM.  Nowadays, many PC PWM fans have excellent noise characteristics, and the "squeal" is only an issue with el-cheapo ones; but it used to be an issue with basically all early PWM-controlled PC fans.  Just go look at old SilentPCReview stuff, for example.)
In my experiance, the sound of the air moving throuh the fan blades, dominates that of the motor.

No mention of PWM was mentioned. I very much doubt noisy brushed motors driven by PWM will be used. They'll all use brushless DC, or perhaps a three squirrel cage motor, driven by a small inverter for higher power units.
 

Offline gnuarm

  • Super Contributor
  • ***
  • Posts: 2247
  • Country: pr
Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #24 on: September 04, 2023, 10:21:24 am »
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.

If a fan isn't three speed, I won't buy it.  I almost never use a ceiling fan on high speed and even the second speed is seldom.  I don't like the feeling of the air on me.  It also tends to dry out my eyes.  On the lowest speed,  I have no problems with it. 

Most fans, I find are cranked up too much.  The ventilation fan in my car goes to 11... yes, 11.  I hardly ever use it above 4.  I would like to have settings equivalent to 0.5 and 1.5 though.  They never seem to give much thought that the lower settings need to be spaced closer together.   It's a bit like the logarithmic audio levels... which also run to 11 and are not really logarithmically spaced.
Rick C.  --  Puerto Rico is not a country... It's part of the USA
  - Get 1,000 miles of free Supercharging
  - Tesla referral code - https://ts.la/richard11209
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf