US Ceiling Fan Efficiency Rule Proposal - Page 1
Forum section: electronics / general

author: PwrElectronics
author_rank: Regular Contributor
timestamp: September 02, 2023, 01:23:16 pm
content: 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.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 02, 2023, 01:53:05 pm
content: 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.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 02, 2023, 02:02:49 pm
content: 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.

author: BrokenYugo
author_rank: Super Contributor
timestamp: September 02, 2023, 02:14:08 pm
content: 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.

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 02, 2023, 02:25:44 pm
content: Quote from: joeqsmith on September 02, 2023, 02:02:49 pmFunny 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.

author: ejeffrey
author_rank: Super Contributor
timestamp: September 02, 2023, 05:07:25 pm
content: 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.

author: TimNJ
author_rank: Super Contributor
timestamp: September 02, 2023, 10:33:04 pm
content: 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?

author: bdunham7
author_rank: Super Contributor
timestamp: September 02, 2023, 10:41:57 pm
content: Quote from: TimNJ on September 02, 2023, 10:33:04 pmThe 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.

author: Stray Electron
author_rank: Super Contributor
timestamp: September 03, 2023, 01:24:28 am
content: Quote from: PwrElectronics on September 02, 2023, 01:23:16 pmSee 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.

author: jonpaul
author_rank: Super Contributor
timestamp: September 03, 2023, 01:57:31 am
content: Check % total US energy:US govermnetUS militaryIndustrey, commerce, transportResidential homescommercial real estateThe fans are perhaps 10 e -6 of totoalNow compare US/EU/vs China/India total energyIf biden suceeded 9magically) to reduce all US energy to zero, China and India will continue to use hughe coal, oil nat gasReal solution is nuclear and fusion, nor political theater, in EU or USJust the ramblings of an old retired EE.Jon

author: bdunham7
author_rank: Super Contributor
timestamp: September 03, 2023, 02:41:39 am
content: Quote from: Stray Electron on September 03, 2023, 01:24:28 amFrom 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.

author: coppercone2
author_rank: Super Contributor
timestamp: September 03, 2023, 02:51:26 am
content: I think the government should make you buy a dyson air multiplier

author: ejeffrey
author_rank: Super Contributor
timestamp: September 03, 2023, 04:46:40 am
content: Quote from: bdunham7 on September 03, 2023, 02:41:39 amDepends 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.

author: Zero999
author_rank: Super Contributor
timestamp: September 03, 2023, 10:16:06 am
content: 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.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 03, 2023, 10:51:52 am
content: 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 motorscanbe absolutely silent, but I wonder if any manufacturer bothers to make one thatissilent 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 notdifficultto 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.

author: bdunham7
author_rank: Super Contributor
timestamp: September 03, 2023, 06:27:55 pm
content: Quote from: ejeffrey on September 03, 2023, 04:46:40 amThat 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.

author: Zero999
author_rank: Super Contributor
timestamp: September 03, 2023, 06:42:42 pm
content: 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.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 03, 2023, 07:16:10 pm
content: Quote from: Zero999 on September 03, 2023, 10:16:06 amMiniscule times193 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.

author: Zero999
author_rank: Super Contributor
timestamp: September 03, 2023, 08:42:45 pm
content: Quote from: Jeroen3 on September 03, 2023, 07:16:10 pmTrue, 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.

author: jpanhalt
author_rank: Super Contributor
timestamp: September 03, 2023, 09:29:30 pm
content: 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.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 04, 2023, 05:56:56 am
content: Quote from: Zero999 on September 03, 2023, 06:42:42 pmI've found that lower PWM duty cycles correlate with more noise, rather than less.

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2023, 07:20:21 am
content: Quote from: Nominal Animal on September 04, 2023, 05:56:56 amI 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.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 04, 2023, 08:18:59 am
content: Quote from: Zero999 on September 04, 2023, 07:20:21 amSure, but that's obvious. You must agree that because we're talking about themotortechnology 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 amextremelyaware 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 itused tobe an issue with basically all early PWM-controlled PC fans. Just go look at old SilentPCReview stuff, for example.)

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2023, 09:45:32 am
content: Quote from: Nominal Animal on September 04, 2023, 08:18:59 amIn 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.

author: gnuarm
author_rank: Super Contributor
timestamp: September 04, 2023, 10:21:24 am
content: Quote from: NiHaoMike on September 02, 2023, 01:53:05 pmIf 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.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 04, 2023, 11:28:08 am
content: Quote from: Zero999 on September 04, 2023, 09:45:32 amBrushed? 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 thatwilllead 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 willinsistthat the inertia and coil inductanceissufficient 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.

author: tszaboo
author_rank: Super Contributor
timestamp: September 04, 2023, 12:33:38 pm
content: 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.

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2023, 01:30:36 pm
content: Quote from: Nominal Animal on September 04, 2023, 11:28:08 amI'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.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 04, 2023, 01:41:40 pm
content: Quote from: Zero999 on September 04, 2023, 01:30:36 pmNevertheless, 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).

author: coppice
author_rank: Super Contributor
timestamp: September 04, 2023, 01:43:07 pm
content: Quote from: Zero999 on September 04, 2023, 01:30:36 pmReally? There are huge numbers of BLDC motors which make considerable noise at quite low frequencies, presumably a beating sub-multiple of the switching frequency.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 04, 2023, 02:18:01 pm
content: Quote from: coppice on September 04, 2023, 01:43:07 pmHarmonics from the square wave switching. The quiet fans like Noctua use sine waves for that reason.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 04, 2023, 02:42:01 pm
content: Quote from: Zero999 on September 04, 2023, 01:30:36 pmHigher-end PC fans have been using PWM for quite some time, and this is actually toreducenoise, namely torque ripple and the related low-frequency vibration and low-frequency noise (which, in case of small fans with high RPM, is notthatlow 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.

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2023, 08:11:59 pm
content: Quote from: coppice on September 04, 2023, 01:43:07 pmYes, the noise predominately comes from the blades cutting through the air.Quote from: Nominal Animal on September 04, 2023, 01:41:40 pmI 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.

author: coppice
author_rank: Super Contributor
timestamp: September 04, 2023, 08:59:38 pm
content: Quote from: Zero999 on September 04, 2023, 08:11:59 pmPlease 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.

author: Dacian
author_rank: Contributor
timestamp: September 04, 2023, 09:06:05 pm
content: Quote from: tszaboo on September 04, 2023, 12:33:38 pmIs that a typo or is your monthly bill 1500USD ?At $0.1/kWh that means 15MWH per month.

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2023, 09:09:59 pm
content: Quote from: coppice on September 04, 2023, 08:59:38 pmI'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.

author: coppice
author_rank: Super Contributor
timestamp: September 04, 2023, 09:23:34 pm
content: Quote from: Zero999 on September 04, 2023, 09:09:59 pmYou 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.

author: Veteran68
author_rank: Frequent Contributor
timestamp: September 04, 2023, 11:50:27 pm
content: 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.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 05, 2023, 12:48:30 am
content: Quote from: coppice on September 04, 2023, 09:23:34 pmAlthough, he's not very likely to encounter ceiling fans outdoors.

author: tszaboo
author_rank: Super Contributor
timestamp: September 05, 2023, 05:03:29 am
content: Quote from: Dacian on September 04, 2023, 09:06:05 pmMine? 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

author: David Hess
author_rank: Super Contributor
timestamp: September 05, 2023, 05:16:07 am
content: Quote from: PwrElectronics on September 02, 2023, 01:23:16 pmThat 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.QuoteNot 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?

author: JPortici
author_rank: Super Contributor
timestamp: September 05, 2023, 08:23:50 am
content: Quote from: NiHaoMike on September 02, 2023, 01:53:05 pmThese 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?

author: gnuarm
author_rank: Super Contributor
timestamp: September 05, 2023, 09:57:05 am
content: Quote from: David Hess on September 05, 2023, 05:16:07 amI think I would not buy a Maytag any more.

author: David Hess
author_rank: Super Contributor
timestamp: September 05, 2023, 10:26:17 am
content: Quote from: gnuarm on September 05, 2023, 09:57:05 amWhat 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.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 05, 2023, 12:44:52 pm
content: Quote from: David Hess on September 05, 2023, 05:16:07 amI 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.

author: David Hess
author_rank: Super Contributor
timestamp: September 05, 2023, 01:53:12 pm
content: Quote from: NiHaoMike on September 05, 2023, 12:44:52 pmI was thinking of replacing it with the original shaded pole motor that the electronically commutated motor replaced.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 05, 2023, 02:58:16 pm
content: Quote from: NiHaoMike on September 05, 2023, 12:44:52 pmDust 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 aNoctua NF-A14 industrialPPC-3000 PWMfan (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 ityet, 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.Quote from: David Hess on September 05, 2023, 05:16:07 amI 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.)

author: David Hess
author_rank: Super Contributor
timestamp: September 06, 2023, 12:15:12 am
content: Quote from: Nominal Animal on September 05, 2023, 02:58:16 pmThe 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.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 08, 2023, 11:12:11 am
content: 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.

author: gnuarm
author_rank: Super Contributor
timestamp: September 08, 2023, 11:47:45 am
content: Quote from: Siwastaja on September 08, 2023, 11:12:11 amYour 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.

author: wraper
author_rank: Unknown
timestamp: September 08, 2023, 12:15:33 pm
content: Quote from: Nominal Animal on September 04, 2023, 01:41:40 pmIdiot engineer phenomenon. Appnote about of how to make ridiculous garbage a little bit less of garbage. You cannot safely PWM power of 99% of brusheless fans to begin with. Brusheless fan speed must be controlled through its PWM wire (if present) or by adjusting DC voltage, not PWMing it's power. Yet some engineers think it's fine despite fans generally having an electrolytic capacitor across their power and driver IC which are not supposed to be abused this way. Heck, Sunon even explicitly forbids it in their datasheets, I guess because there are enough idiots who think otherwise.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 08, 2023, 01:45:02 pm
content: Quote from: wraper on September 08, 2023, 12:15:33 pmAgreed; and those engineers get paid to do that only because it ischeaperthan doing it properly.On the PC fan side, those motor designs got kicked in the teeth as users basically rejected them, and even the cheapest mass producers have shifted to more sensible driving schemes.Ten to twenty years ago, there were only very minor differences between fan blade designs, with quiet fans just having blade geometry well matched to their motor. Nexus was the bees knees back then for general use. Gentle Typhoon had optimal geometry for intake fans, as they could deal with filters' airflow impedance without becoming noisy. 3-pin (voltage controlled, no PWM) fans were quieter and with nicer noise spectrum than 4-pin PWM-controlled fans, as you can find out yourself by looking at fan noise comparisons back then (by SPCR for example). Noctua started with good CPU heatsink designs, with well matched fans; and then went on to optimize their fans for low noise and good airflow by both working on the motor designs (their sinusoidal BLDC drive ICs, bearing designs) and later even on the blade geometry. Now several manufacturers design their own blade geometries with both noise and airflow in mind.Since this already happened with PC fans, taking a decade from the arrival of PWM-controlled fans to actually good motor and blade designs to be available, I'm just afraid something similar will happen with ceiling fans. The current ceiling fan AC motors may not be as efficient as possible, but they for sure are reliable and quiet; the two things that matter to me personally more than the exact power usage. To me, it would be a HUGE step backwards to replace a perfectly good, reliable, quiet ceiling fan with one that has a one-year warranty, a high-pitch squeal I can hear when trying to sleep in the summer, much higher price (due to the more complex construction and electronics), but with lower energy consumption.Sure, I could be wrong. But when something similar has already happened in the past, history tells us things tend to repeat the same way.

author: bdunham7
author_rank: Super Contributor
timestamp: September 08, 2023, 01:54:02 pm
content: Quote from: Siwastaja on September 08, 2023, 11:12:11 amIn fact, to the extent that the government causes the issue by mandating levels of efficiency that sometimes results in less reliable products, they should mitigate the problem by requiring very long warranty periods. After all, if their goal is to save energy and the environment, surely long-lived appliances results in less manufacturing (consumption of energy and raw materials) and less waste. Recycling is a poor substitute for long product life.By long warranty periods I mean refrigerators/dehumidifiers/AC units - 20 years, clothes washers/dryers/dishwashers - 10 years. Ceiling fans - 50 years.

author: wraper
author_rank: Unknown
timestamp: September 08, 2023, 02:14:05 pm
content: Quote from: Nominal Animal on September 08, 2023, 01:45:02 pmAnd then you have failing fans, whiny noise and rattling sound during fan start. The problem is that I've seen this not only in cheapest devices but where such economy makes not economical sense. I'm pretty sure it's more of incompetency rather than saving $0.05 BOM cost.

author: wraper
author_rank: Unknown
timestamp: September 08, 2023, 02:26:39 pm
content: Quote from: Nominal Animal on September 08, 2023, 01:45:02 pmBLDC is more reliable in general because there is no run capacitor that degrades and they do not heat nearly as much due to high efficiency. Shaded pole motor that is most common in AC fans on other hand is cheap but super inefficient, heats like hell and that heat kills bearings. Not surprising due to ~25% efficiency.

author: RJSV
author_rank: Super Contributor
timestamp: September 08, 2023, 08:06:23 pm
content: Thanks PwrElectronics:First of all, nothing personal, I'm a very criticism filled EE.(We gonna learn and hear about a myriad of Engineering issues, from the mouths of the barely educated. Now, if you think I'm out of line, bringing in the racial diversity dynamics, try figuring out who (may) be pushing for a DC fan style, (ignorant of engineering issues brought up here). Odds are, that person came out of school with a degree in 'Multi-ethnic Studies', and would reply with:"AC, DC, smeecy"....you WILL comply.Were you surprised, when that 'Gas Oven ban' wasn't a one-off thing? A glitch, never to happen again ?In a real situation, (climate change disasters) we are going to need ENGINEERS doing the science. The whole 'diversity thing likely will get plugged in, with any large technology change (shoved down our throats).thanks, there.- - Rick

author: RJSV
author_rank: Super Contributor
timestamp: September 08, 2023, 10:25:20 pm
content: Yes, A DISMISSAL, quite a tired taktic being used these days, to avoid any substantive debate.It's, 'too ridiculous' to even touch....next you should maybe say: (and again, a tired, dismissive phrase), SAY:"You people seem to see a conspiracy behind every tree..."But that would be baiting, after you stepped in the poo.Sometimes you've got to wait, for the consequences to manifest.What other 'delusion' accusing talking points do you have, because (we) can't just sit here calling each other a 'Ninny',No, you're a ninny...back and forth. Why don't you, uh, hit us critical thinkers with some good attacks, rather than repeating same old dismissals.Do you have a gas stove ? Try some effective 'gas lighting' so we can respect your dismissals as being valid.Rejected yours.

author: gnuarm
author_rank: Super Contributor
timestamp: September 08, 2023, 11:15:21 pm
content: Quote from: bdunham7 on September 08, 2023, 08:14:51 pmI was going to say there's no way to show you don't consider a post appropriate to the forum... but there is a link to report the post to the moderator, which I have done. I hope others do as well.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 09, 2023, 05:56:15 am
content: Quote from: wraper on September 08, 2023, 02:26:39 pmThis matches with my experience. "Good old" cheap inefficient AC motors have failure modes such as destruction of run capacitor or destruction of bearings (oil) due to too high operating temperature. BLDC fan has all the chances to be much more reliable. Those that fail fast are outliers; I also strongly agree with bdunham7 that if and when governments apply laws mandating better efficiency, they should be coupled with better lifetime requirements, too.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 09, 2023, 03:43:54 pm
content: Quote from: Siwastaja on September 09, 2023, 05:56:15 amTrue; that should ensure the quality.Yet... When was the last time you remember lifetime requirements beingextended?Here in Finland, the climate is quite challenging for house builders, swinging from an occasional -40°C in coldest winters to +30°C during hottest summers.Yet, the typical warranty period is only 5 years, and most houses are designed for only a 30 - 50 yearlifetime.Now that EU will require much, much higher energy efficiency for houses, they have not and will not address the warranty period or manufacturer/builder responsibility at all. Funny thing is, you could achieve the energy efficiencies easily, simply by making thicker walls. Apartment buildings built 100-150 years ago in Helsinki still fulfill even the strictest energy efficiency requirements, simply because they have walls half a meter thick of stone and concrete. That will not happen, because new is always better and "we can achieve the same energy efficiency with these layered plastic and insulator structures" (which will be first-rate grow zones for mold as the sharp temperature differences will cause water to condensate there, and there is no mechanism to dry it out). The apartment I'm renting right now, for example, has such an outer wall structure that if you were to screw anything into the outer wall, you'd compromise the vapourtight barriers and the outer wall, and possibly compromise the long-term stability of that outer wall altogether. This is relatively common in new buildings, too.Thus, while longer lifetime requirement would obviously make the primary worries go away, I do not see such requirements happening at all.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 09, 2023, 09:19:38 pm
content: Quote from: Nominal Animal on September 09, 2023, 03:43:54 pmI don't either. And actually, if you set no lifetime requirement, efficiency requirements are possibly going to lead to shorter lifetimes in practice.