Author Topic: US Ceiling Fan Efficiency Rule Proposal  (Read 6716 times)

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Offline Nominal Animal

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #25 on: September 04, 2023, 11:28:08 am »
I very much doubt noisy brushed motors driven by PWM will be used.
Brushed?  Where did you pull that out from?  You're the only one who has mentioned anything to do with brushed motors here.
I'm starting to think you know nothing about this, and are just spouting your gut feelings as if they were facts.

PC fans were always BLDC, with the PWM frequency between 21 kHz and 28 kHz (25 kHz typical).  RPMs vary between 300 and 3000, i.e. between 5 and 50 rotations per second (although smaller, 40mm fans as used in servers can be significantly faster – and horribly loud with a whiny sound spectra).

The cheapest way to implement a small PWM-controlled BLDC fan is to drive the coils using a half bridges (with BJTs or FETs) directly modulated by the PWM.  This is possible, because the duration each coil is powered is many PWM cycles long, even at the highest speeds.  Especially at low PWM duty cycles (thus low RPMs), this causes a noticeable characteristic whine.  It is more noticeable with larger fans (120mm and larger), unless they use better driving schemes like e.g. Noctua uses – either proper filtering, or using a proper BLDC driver that only uses the PWM as a control input and not directly to modulate the output coils.  It was such a problem that all but the cheapest manufacturers have had to shift to better filtering and driving schemes, because the cheap ones were rejected by the customers.  Today, if you open up any but the very cheapest PC PWM fans, you'll find a dedicated IC and quite a few components in the hub PCB.

Ceiling fans rotate at very low RPMs, say 30 - 300, and with their large blades, have quite heavy fan blade assemblies.  Thus, it will be in the interests of the cost-cutting manufacturers to rely on the blade inertia and coil inductance for the filtering, and that will lead to audible motor noise.  (I am not talking about levels audible in an office environment with idiots blathering on the phone nearby, I'm talking about the important situation: using a ceiling fan to help one sleep better.)

I am absolutely certain there are many members on this forum who will insist that the inertia and coil inductance is sufficient filtering.  It is demonstrably not so to me.

Compare to e.g. TI TPS61165 and TPS61169 high-current boost LED drivers with 5 kHz - 100 kHz PWM dimming control.  They do not use the input PWM signal to modulate ("burst") the LED current either, because it causes audible noise in the output capacitors at (multiples of) the PWM frequency.
Is this just marketing wank?  No, those who do care know about the difference it makes in quiet environments.  Do all manufacturers use such techniques?  Definitely not.  Many of the cheaper 12V (CV) or 350mA (CC) LED drivers do emit audible (to me) noise around 20 kHz, say between 10 kHz and 25 kHz, especially so with low duty cycles (load on the lower end of the power the driver is specced for).  I do not use those, either, which means I can only buy from places that let me return the item if they do produce such a sound.

Thus far, audible noise, especially near-ultrasound noise, seems to be something completely ignored by policymakers.  They only consider the acoustic power, and not the audio spectra.  Yet, white noise is soothing, but a pure sine wave at the same loudness can drive a person crazy.
I wonder if it is because their own hearing is utter shit, or whether they just don't understand things that affect themselves.
« Last Edit: September 04, 2023, 11:30:35 am by Nominal Animal »
 

Offline tszaboo

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #26 on: September 04, 2023, 12:33:38 pm »
TBH I saw a few American Youtuber do solar installation, and they always go with ridiculous numbers.
"I'm paying 10 cents a KWh and my monthly bill is 1500 USD" or something like that. And then they install a 100.000 dollar solar installation with enough batteries to run a small European city.
So yeah. You could use more regulations on the efficiency, especially on HVAC.
 

Offline Zero999

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #27 on: September 04, 2023, 01:30:36 pm »
I very much doubt noisy brushed motors driven by PWM will be used.
Brushed?  Where did you pull that out from?  You're the only one who has mentioned anything to do with brushed motors here.
I'm starting to think you know nothing about this, and are just spouting your gut feelings as if they were facts.

PC fans were always BLDC, with the PWM frequency between 21 kHz and 28 kHz (25 kHz typical).  RPMs vary between 300 and 3000, i.e. between 5 and 50 rotations per second (although smaller, 40mm fans as used in servers can be significantly faster – and horribly loud with a whiny sound spectra).

The cheapest way to implement a small PWM-controlled BLDC fan is to drive the coils using a half bridges (with BJTs or FETs) directly modulated by the PWM.  This is possible, because the duration each coil is powered is many PWM cycles long, even at the highest speeds.  Especially at low PWM duty cycles (thus low RPMs), this causes a noticeable characteristic whine.  It is more noticeable with larger fans (120mm and larger), unless they use better driving schemes like e.g. Noctua uses – either proper filtering, or using a proper BLDC driver that only uses the PWM as a control input and not directly to modulate the output coils.  It was such a problem that all but the cheapest manufacturers have had to shift to better filtering and driving schemes, because the cheap ones were rejected by the customers.  Today, if you open up any but the very cheapest PC PWM fans, you'll find a dedicated IC and quite a few components in the hub PCB.

Ceiling fans rotate at very low RPMs, say 30 - 300, and with their large blades, have quite heavy fan blade assemblies.  Thus, it will be in the interests of the cost-cutting manufacturers to rely on the blade inertia and coil inductance for the filtering, and that will lead to audible motor noise.  (I am not talking about levels audible in an office environment with idiots blathering on the phone nearby, I'm talking about the important situation: using a ceiling fan to help one sleep better.)
I've never seen a BLDC motor driven in that manner.  All the fans I've seen have a Hall effect sensor, connected to some transistors which emulate a mechanical commutator.

I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
 

Offline Nominal Animal

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #28 on: September 04, 2023, 01:41:40 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Nevertheless, it is a well known phenomenon.  Microchip even made an appnote (AN771: Suppressing Acoustic Noise in PWM Fan Speed Control Systems) about it in 2002.  Feel free to ignore me (many do, and that's okay), but please do read that appnote to understand the issue I'm trying to bring up.  It affects slow high-current/high-load (large fan assembly) fans in particular, so therefore definitely does apply to BLDC ceiling fan motors also (or rather, their control circuitry, which is basically the only part manufacturers can cost-cut anymore, with just about everything else being basically standard).
« Last Edit: September 04, 2023, 01:43:46 pm by Nominal Animal »
 
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Offline coppice

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #29 on: September 04, 2023, 01:43:07 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
 

Online NiHaoMike

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #30 on: September 04, 2023, 02:18:01 pm »
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
Harmonics from the square wave switching. The quiet fans like Noctua use sine waves for that reason.
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Offline Siwastaja

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #31 on: September 04, 2023, 02:42:01 pm »

PC fans were always BLDC, with the PWM frequency between 21 kHz and 28 kHz (25 kHz typical).  RPMs vary between 300 and 3000, i.e. between 5 and 50 rotations per second (although smaller, 40mm fans as used in servers can be significantly faster – and horribly loud with a whiny sound spectra).
I've never seen a BLDC motor driven in that manner.  All the fans I've seen have a Hall effect sensor, connected to some transistors which emulate a mechanical commutator.

Higher-end PC fans have been using PWM for quite some time, and this is actually to reduce noise, namely torque ripple and the related low-frequency vibration and low-frequency noise (which, in case of small fans with high RPM, is not that low of frequency, but in several hundreds of Hz, is annoying to filter out, requiring soft mounting materials etc.) This is because in a simple hall-based, directly switched BLDC, a two-phase motor is out of optimal drive angle by +/- 45 degrees and three-phase motor by +/- 30 degrees. (It's just like if you had a clock which only had a hours hand and advanced one full hour click every hour, it would be off by +/- 30 minutes).

Using more sophisticated drive circuitry (FOC or something similar), you can add resolution into rotor position sensing (maybe just by interpolation), which allows you modulate the drive sinusoidally (or whatever happens to be the optimal wave shape based on motor design), creating torque vector which is always 90 degrees in advance compared to real physical rotor angle, producing smooth torque without ripple. The downside is that unless you build a linear amplifier (which would be quite crazy, and inefficient), you have to create the smoothly changing current levels by PWMing the motor windings, and you create a new noise problem. But it can be at higher frequencies, beyond the human's hearing.
« Last Edit: September 04, 2023, 02:44:58 pm by Siwastaja »
 
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Offline Zero999

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #32 on: September 04, 2023, 08:11:59 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
Yes, the noise predominately comes from the blades cutting through the air.

I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Nevertheless, it is a well known phenomenon.  Microchip even made an appnote (AN771: Suppressing Acoustic Noise in PWM Fan Speed Control Systems) about it in 2002.  Feel free to ignore me (many do, and that's okay), but please do read that appnote to understand the issue I'm trying to bring up.  It affects slow high-current/high-load (large fan assembly) fans in particular, so therefore definitely does apply to BLDC ceiling fan motors also (or rather, their control circuitry, which is basically the only part manufacturers can cost-cut anymore, with just about everything else being basically standard).
I didn't know anyone in real life actually tried to control a BLDC motor in that manner. I've seen people talk about it here, but I haven't seen it in a commercial product. It's not very reliable because the motor driver has to keep restarting and it will draw large current spikes, due to the decoupling capacitors.

Variable speed fans inside computers and ventilation systems, have a separate PWM input, which is decoded internally by the motor driver and doesn't PWM the whole thing, so there's no noise.
 

Offline coppice

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #33 on: September 04, 2023, 08:59:38 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
Yes, the noise predominately comes from the blades cutting through the air.
Please try to make sense. Reading comments before responding might help. Where did I mention blades? The subject was motors, not their specific use in fans.
 

Offline Dacian

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #34 on: September 04, 2023, 09:06:05 pm »
TBH I saw a few American Youtuber do solar installation, and they always go with ridiculous numbers.
"I'm paying 10 cents a KWh and my monthly bill is 1500 USD" or something like that. And then they install a 100.000 dollar solar installation with enough batteries to run a small European city.
So yeah. You could use more regulations on the efficiency, especially on HVAC.

Is that a typo or is your monthly bill 1500USD ?At $0.1/kWh that means 15MWH per month.
 

Offline Zero999

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #35 on: September 04, 2023, 09:09:59 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
Yes, the noise predominately comes from the blades cutting through the air.
Please try to make sense. Reading comments before responding might help. Where did I mention blades? The subject was motors, not their specific use in fans.
I've yet to encounter a fan who's motor is louder, than the air. Occasionally there might be a slight hum from the motor, but it's nothing compared to the wind.
 

Offline coppice

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #36 on: September 04, 2023, 09:23:34 pm »
I can't say I've ever noticed any whine from a BLDC motor, even when I was much younger and could hear over 20kHz.
Really? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.
Yes, the noise predominately comes from the blades cutting through the air.
Please try to make sense. Reading comments before responding might help. Where did I mention blades? The subject was motors, not their specific use in fans.
I've yet to encounter a fan who's motor is louder, than the air. Occasionally there might be a slight hum from the motor, but it's nothing compared to the wind.
You need to get out more. With big ceiling fans that don't generally spin very fast, as the huge blades move lots of air at low speed, the motor can be VERY annoying and you just don't hear the air being moved.
 

Offline Veteran68

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #37 on: September 04, 2023, 11:50:27 pm »
Maybe it's my hearing but I don't believe I've EVER heard air moving from a ceiling fan, even on high speed. Certainly not on low or medium speeds, which is where ours tend to stay. We sleep under a ceiling fan that runs 24/7/365, even in winter. I don't hear anything.

In our last house our bedroom ceiling fan motor could be heard at higher speeds, it was clearly motor hum/whine and not wind noise. But it's a >25 year old design, installed when the house was built in 1998. Our current house was built in 2021 which we bought as new construction, I have no idea what type of fan it is. Pretty sure it was a Home Depot special, nothing fancy.
 

Online SiliconWizard

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #38 on: September 05, 2023, 12:48:30 am »
I've yet to encounter a fan who's motor is louder, than the air. Occasionally there might be a slight hum from the motor, but it's nothing compared to the wind.
You need to get out more.

Although, he's not very likely to encounter ceiling fans outdoors.
 

Offline tszaboo

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #39 on: September 05, 2023, 05:03:29 am »
TBH I saw a few American Youtuber do solar installation, and they always go with ridiculous numbers.
"I'm paying 10 cents a KWh and my monthly bill is 1500 USD" or something like that. And then they install a 100.000 dollar solar installation with enough batteries to run a small European city.
So yeah. You could use more regulations on the efficiency, especially on HVAC.

Is that a typo or is your monthly bill 1500USD ?At $0.1/kWh that means 15MWH per month.
Mine? No, I am not an American.
But here is a guy who was using apparently 54 MWh of electricity in a year. And I see more and more of these ridiculous numbers.

https://youtu.be/UJeSWbR6W04?si=pG-uF2NdsVYQxxK6
 

Online David Hess

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #40 on: September 05, 2023, 05:16:07 am »
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.

That is right; the AC shaded pole or induction motor or whatever is replaced with an electronically commutated motor, which can be just a shaded pole motor armature with the current shorts removed and a rotor position sensor added.

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

Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

Do you think a tiny shaded pole motor would have used $125 dollars worth of electricity over 10 years?
 

Offline JPortici

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #41 on: September 05, 2023, 08:23:50 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.

These are things that should remain simple and dumb.  It's just a ceiling fan, like it's just an hair drier. we tried to repair a dyson hair drier, no can do because the microcontroller failed. Sure it's a sleek design, sure it's quieter, sure it's more efficient, but the added complexity is not justified.

Do you waste more energy with a dumb fan/drier/other tool that will probably break 20 years or more from now and are trivial to repair, or with multiple more efficient tools that don't last anywhere as much?
 

Offline gnuarm

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #42 on: September 05, 2023, 09:57:05 am »
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.

That is right; the AC shaded pole or induction motor or whatever is replaced with an electronically commutated motor, which can be just a shaded pole motor armature with the current shorts removed and a rotor position sensor added.

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

Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

Do you think a tiny shaded pole motor would have used $125 dollars worth of electricity over 10 years?

I think I would not buy a Maytag any more.
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Online David Hess

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #43 on: September 05, 2023, 10:26:17 am »
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.

That is right; the AC shaded pole or induction motor or whatever is replaced with an electronically commutated motor, which can be just a shaded pole motor armature with the current shorts removed and a rotor position sensor added.

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

Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

Do you think a tiny shaded pole motor would have used $125 dollars worth of electricity over 10 years?

I think I would not buy a Maytag any more.

What brand would you buy?  Most are owned by the same company as Maytag, and they all use the same motors anyway.

Maytag, Whirlpool, Amana, Kenmore, LG, and Frigidaire are all the same company.
 

Online NiHaoMike

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #44 on: September 05, 2023, 12:44:52 pm »
Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

Do you think a tiny shaded pole motor would have used $125 dollars worth of electricity over 10 years?
I would have replaced it with a PC type fan and a sealed Mean Well power supply module. I almost never see a PC fan fail for any reason other than worn out bearings.
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Online David Hess

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #45 on: September 05, 2023, 01:53:12 pm »
Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

Do you think a tiny shaded pole motor would have used $125 dollars worth of electricity over 10 years?

I would have replaced it with a PC type fan and a sealed Mean Well power supply module. I almost never see a PC fan fail for any reason other than worn out bearings.

I was thinking of replacing it with the original shaded pole motor that the electronically commutated motor replaced.
 

Offline Nominal Animal

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #46 on: September 05, 2023, 02:58:16 pm »
I almost never see a PC fan fail for any reason other than worn out bearings.
Dust kills them easily, so I'm not sure they live very long at the back of a fridge where dust tends to build up.

I just got a Noctua NF-A14 industrialPPC-3000 PWM fan (IP52 rating) I'll test my own PWM fan driver board with, that might be suitable, but it is also relatively expensive.  I haven't tested it yet, though.

My current fridge (Rosenlew) uses R600a refrigerant, a butane isomer, which has the downside of occasional gurgling noise after a cooling cycle.  It is definitely noisier than my previous one (Electrolux or Upo, can't recall).  I'm renting an apartment right now, so switching is not an option for now.

Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.
I assume the airflow is okay, and that it was the controller that burned, not the motor itself?

Here in Finland, fridge-freezer combinations are often put inside kitchen cabinets, with insufficient airflow.  Often there is only the absolute minimum aperture above the fridge (for "exhaust", cold air intake being at the floor level behind the kickplate).  Many use that nice little slot for kitchen appliance paperwork, and don't realize that blocking it will cause the fridge to burn out in a few years.  (Mine has a moveable shelf above it, being cheap Ikea-style melamine-coated particle board cupboard, so I've moved it an inch higher, just to be sure.)

Some (non-industrial) motors also use bearings that do not tolerate dust, generating a heavy load as the grease and dust forms into a thick sticky heavy paste, eventually burning the motor out from the load.  Apparently, using rubber sealed bearings from the get go would have hurt the energy efficiency or cost too much, and it is more cost-effective to spec the motor at the very borderline of its load.  (I suspect, but am not sure, that it is the intermittent operation that allows the dust ingress into bearings unless sealed.)
 

Online David Hess

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #47 on: September 06, 2023, 12:15:12 am »
Not only are electronically commutated motors a lot less reliable, but they are a lot more expensive.  In 10 years I have had to replace the Swiss made electronically commutated motor for the evaporator fan in my Maytag refrigerator 5 times at a cost of more than $25 each time.  I think what is going on is power line surges are burning out the electronics.

I assume the airflow is okay, and that it was the controller that burned, not the motor itself?

The motors sure did not overheat, since it is mounted in the freezer adjacent to the evaporator.  And the failure is not in the bearings.  Every one failed by only turning at low speed.  The electronics are potted so there is no access.
 
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Offline Siwastaja

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #48 on: September 08, 2023, 11:12:11 am »
Today electronics are literally everywhere, and relative to that widespreadness, reliability problems are rare. I don't think preferring older, less efficient (both energy efficiency and cost efficiency of manufacturing) just "for reliability" is a good argument. This is like saying we need to keep riding horses because some early cars were unreliable. Instead, we should demand reliable electronics, because the 99% of cases show that this is entirely possible.
 
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Offline gnuarm

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Re: US Ceiling Fan Efficiency Rule Proposal
« Reply #49 on: September 08, 2023, 11:47:45 am »
Today electronics are literally everywhere, and relative to that widespreadness, reliability problems are rare. I don't think preferring older, less efficient (both energy efficiency and cost efficiency of manufacturing) just "for reliability" is a good argument. This is like saying we need to keep riding horses because some early cars were unreliable. Instead, we should demand reliable electronics, because the 99% of cases show that this is entirely possible.

Your analogy is false.  The reliability issues of appliances are real, and should be taken into account when considering the level of technology to purchase.  If such devices were actually as reliable as a basic ceiling fan, they would have the same 10 year warranty.  Do they? 

There are any number of electronic devices which connect to 120VAC/240VAC and fail often from the power surges that are common in many places.  The manufacturers know exactly what the electrical environments are like.  They choose to not protect devices based on how it impacts the selling price vs. reliability.  Ceiling fans are devices that are often bought on price alone, so poor surge protection if they contain fancy electronics.

In contrast, the one feature that is cheap to provide, and does seem to offer significant perceived "value" are remote controls.  They seem to be on nearly everything, including AC units and ceiling fans.  The point is, they provide a perceived value, so get included in any but the very cheapest of units.  Surge protection is something virtually no one knows about, other than the outlet strips that people think will stop lightning bolts.
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