Do any ultra quiet ceiling fans that have no motor hum exist?

Question

I am in the market to buy two large ceiling fans to cycle air within and potentially cool my master bedroom. The room is about 16x27 feet, and it gets pretty hot during spring, summer, and early fall. I have wired both mounts into the ceiling, and tried out a single 52" Harbor Breeze fan in one of them. The fan produced a very audible motor hum, similar to that described in this question, however strait off of my native power. Cranking the fan up to high speed would drown out the sound of the hum, but then I have the fan noise itself to deal with. I've had an electrician come out and check the wiring, and everything is solid according to him.

From a wiring standpoint, I used a Harbor Breeze remote control with the fan, which was nicely designed to fit within and work perfectly with the Harbor Breeze fan itself. Wiring the remote control receiver was a no brainer...every connection was color coded. I did notice, however, that the wires from the fan itself were solid core, where as the wires from the remote receiver were stranded aluminum. I am not sure if this might cause a problem, and introduce motor hum? Having a remote is important (see background below for why.)

I did some searching, and there seem to be a variety of complaints about Harbor Breeze fans and motor hum (and an even broader search indicates that motor hum is not an infrequent problem.) Do ceiling fans of high enough quality, with large enough motors to run the fan silently, actually exist? Is it possible to get a ceiling fan that works with a remote without motor hum?

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Background

I have severe sleep issues, one of them being high sensitivity to noise. When its hot, I have even more trouble sleeping, and I expend a considerable amount of money running my air conditioner to keep my home cool during the summer. I am close to desperate to find a way to cool my room without the need to run my air conditioner as much, and ceiling fans seem to be the ideal solution. I've lived in apartments in the past that had truly silent ceiling fans, and I was able to sleep well with them. I'm largely just lacking information and knowledge about what brands I should be looking at, what price point I should be looking at (I think I spent about $200 on the one 52" Harbor Breeze before, from Lowes, but I'm willing to spend twice that or more per fan if it gets me a quiet one without motor hum.)

Given my sleeping issues, I need to be able to turn the fan on or off without getting out of bed. Generally speaking, if I get up once I've finally started to fall asleep, my night is over...I don't sleep at all. I used a remote with the Harbor Breeze, however I think that may have made the motor hum worse...as the wiring of the receiver was really cheap. Are there any known high quality remote receivers that use proper wiring and support the right kind of electric load for a large ceiling fan?

Answer 1

You might look into ceiling fans with DC motors. While I have not seen a manufacturer talk about quietness, some reviews I've read talk about quietness. The biggest attraction to DC motors is the efficiency of the motors, getting more air movement with less power.

My suggestion would be find a local fan / light showroom that has some of these on display that you can try.

Also, fan speed controls have a lot to do with the fan noise. A fully variable wallbox style speed control can cause motor noise, but the fan speed controls that have preset "clicks" that you feel when adjusting are made for quiet operation. I don't know if the remote set you got was matched by the manufacturer or just off the shelf, but that could make a difference.

You also have to remember that some people leave their fans on for a "white noise" effect, which helps them (me) sleep. My wife insists that we keep a floor fan on for the noise. Because of this, when it comes to trouble shooting a loud motor then you might not get as much help as you think you would get.

Again, try a fan specialty shop. The salespeople will know which are quieter and should know more about them than a box store.

Answer 2

Most electronic noise is made by the AC cyclic voltage, which is audible whenever that wave is transferred into something that can vibrate. That noise generally becomes more prominent (changing from a hum to a buzz) when there is something that changes the waveform to produce sharp "corners" (a "square wave"). A particularly noisy combination is a TRIAC wall dimmer and an electric motor; the TRIAC only allows current to pass when the voltage is above a certain (adjustable) threshold, creating an extremely "jagged" waveform. The motor then gets these sharp spikes of current which can induce sympathetic vibrations in the armature.

So, if you're trying to avoid fan noise, the first step is to remove any wall dimmers on this circuit. You should instead use a fan control module that is specifically designed for fans; it will step down the voltage in a way that won't create such a jagged waveform.

Second, yes, some fans are quieter than others. Generally the beefier the motor is, and the newer the fan, the less it will hum. As the fan ages it will begin humming more, especially if you don't reverse the motor direction during the winter (it's as much a maintenance thing as it is circulating air in the "proper" direction). But, I installed a Harbor Breeze fan, one of the cheapest in the store, and it's hum-less until you put it on high.

Answer 3

The fan will never be completely silent. As Tester101 said in the comments, the even if the motor is silent, the blades moving in the air will still make noise (sometimes a lot!).

There are two sources of noise you need to minimize - the motor and the blades.

Fans are loudest when at full power and tend to get quieter when the power is reduced. What I've been successful with is purchasing a fan that is larger/more powerful then needed but running it at reduced power by means of a fan speed controller. A higher quality unit is likely to be quieter too. I don't know about the brand you are referencing, but you might want to check with a more specialized supplier, and you should definitely experiment with different brands (big box store return policies make this relatively easy).

The different configurations (size, material, angle, number of blades) of fans will affect noise level as well. Again, experimenting might help you find the best solution.

I would worry about how to remotely control it last - there are a lot of options for this.

Check the unit specifications, you might get lucky and find some information on the amount of noise (in dB). If not try asking the manufacture.

Answer 4

Fan motor noise is greatly amplified if the fan motor housing is fastened directly to the ceiling. Instead, using even a short 4" down pole will dramatically reduce motor noise. Without the down pole, motor noise is hard coupled to the ceiling, which then acts like a giant speaker cone.

The size and composition of the connector wires has no effect on motor noise. Motor noise is caused by low quality bearings, loose windings in the motor, and poor vibration isolation.

Fan blade wind noise is affected by the shape of the blades. The most common flat blades are probably the worst. The molded blades that are formed more like a genuine air foil propellor are probably the quietest. Look for the inner part of the blade to be wider and more curved than the tip, which should be thinner and flatter.

Answer 5

The sounds associated with a ceiling fan can be extremely annoying, as you say in your post, you dont expect the fan to be completely silent, just to have a good sound profile that can easily become white noise, (for me, this means to excessive noise & no deviation from rhythm)

I can think of the following factors causing noise:

Air Flow: This is associated with the fan pushing the air - solution: more ergonomic fan blades.. see sycamore fan

Bearings: Quality bearings on the fan will reduce the friction associated with the rotation, generally this is not the source of the noise, only on old worn fans. - Factors for consideration: to minimise noise here, a heavy fan-motor/housing base will cause both the bearings and noise absorption to be improved. Also, make sure that the fan blades are not bent or unbalanced. since an unbalanced fan will definitely send noise through to the motor. You can test for this type of noise if you hold the fan motor base with your hand while the fan is on low speed (please be careful here) or take each blade off and measure the weight with a kitchen scale.

Motor Driver and speed Control: modern motors use a chopper driver (traic) to regulate the speed (therefore torque) of the motor, this may cause a whining hum. this noise may get louder at low speeds (low torque) - A good quality driver should not make noise, so this would be as a result of the build quality of the fan.

Motor Windings (stator) Most of the noise comes from the ac current running through the windings (copper wire on the stator) . noise will come be generated from the ac frequency vibrating each strand slightly (to the hz of the ac pattern)... there is a technique called dipping, where these coils are coated in a non conductive epoxy or tape, where the noise profile is improved substantially. (this would not a recommended solution since its quite technical.. just added for information see Epoxy Resin for motors

Answer 6

There is such a thing as a silent fan. We have a 25 years old Hunter Fan in our bedroom. It is absolutely silent and I can hear a pin drop at night. We have two other Hunter Fans that are quiet but not silent. So you have to research which style Hunter Fans are the silent ones.

Answer 7

you can solve all issues for quietness by purchasing a midpriced CASABLANCA FAN - they have FOUR speeds and among the quietest fans i have ever used. I had replaced all past bedroom fans as they continued to hum or make noise even when new. finally an electrician advised use casablanca fan....it worked!! yes more expensive but will last 25 years and even on highest speed which will blow your room out, its super duper quiet ! look at casablanca on AMAZON.com LASTLY DC motor fans are amazing, min cost i think around 300.oo or so but absolutely quiet and will (and should) last a lifetime - hope that helps signed someone who is light sleeper and has tried every ceiling fan model out there!

Answer 8

Solved this by filtering the mains!

You are right that at very low revolutions, the main noise is the power hum. I tried to solve this for years, and eventually realized the hum is actually not the 50/60 Hz of the mais: that frequency is very low and can not be easily heard. What you hear is HARMONICS, the higher, audible overtones created by the distortion of regulator, when chopping small bits of the mains power wave. Solution was filtering the mains by a so called LC filter: basically, an inductance used in bar fluorescent lights as ballast (just any size will probably do), in series with a motor running capacitor (edited: not a starting capacitor). 4 uF value in my case. The filter is connected in series with the fan itself. The filter also substantially reduces the power that gets to the motor in proportion to the capacitor value, serving INSTEAD of a regulator. You can add a switch to short circuit this filter to get the fan back to full power in daytime.

Answer 9

Nowdays with the newer govt energy standards, you will find many hi-performance fans, meaning 12-14 degree blade pitch will have a slight motor hum. Others from box stores will most likely be more noisy based upon the quality of copper in the motor and the capacitor ratings. Most of the money to build box store fans is put to the aesthetics, and not performance. DC fans to tend to be quieter, but any electrical imbalance can give the motors a growling sound. Given too, they are much more complicated electronics, and nearly all are hand held remotes only! Some of the old US made Hunter original fans with the oil bath bearing, were indeed pretty quiet. Today all Hunter fans are made in China, made for a price point, to retail at builder box stores. My 35 years in the fan industry I've seen many changes, some good and many not so good....

Answer 10

I recommend you check out Big Ass Fans.

Answer 11

There is a new fan on the market called the "Exhale Fan" it takes everything we are wanting and talking about to a whole new level. DC motor, blade less fan, toroidal air flow, ultra quiet.

Answer 12

Even with an 8' ceiling, you can use a 4" drop down pole for silence. Buy or make a cage. It can be mounted to the ceiling. It can be open on the sides for easy access for cleaning and maintenance. This would be only a bottom screen to guard the blades.

Answer 13

For what it's worth, I put in three ceiling fans when I moved in (the house already had two), and normally I barely hear motor noise from them -- the whoosh of the blades, and the occasional quiet rattle of something in the air flow, are louder. These are wired directly, using only the three-step speed control built into the fan.

So I tend to agree that the fancy-but-not-fancy-enough speed controllers are likely to be your problem. Or much older or cheaper fans. (Though these three are middle-of-he-line from a decent manufacturer, they are less than a decade old.)

How they're mounted may also make a difference, though mine are mostly attached directly to the ceiling with at most a short, rigid standoff.

Shop around, try in stores, try in friends' 'homes... It is possible. Good luck.

Answer 14

Everything I've read and seen point for electronic hums point to too-rapid-switching of the 60Hz current -- with some dimmer switches not designed for fans making the problem worse.

But first, lets say you are using the 3-speed switch that was designed for fan, and that it is properly designed (bit assumption, but looking at best case first). In that case, its the pure 60Hz (60 full sine-waves/second) current. In this case, you need to smooth out that out (with result of slightly less fan power though that's usually not noticeable). To do that, use a capacitor. I'm looking at one I salvaged off of a good (no audible hum) floor fan that died after 15 years of use. I'm hoping to transplant it onto a Chinese special that has both vibration (physically caused) AND hum. I can't find evidence that it contains a capacitor, so I hope for it to be a good test of this relatively easy fix.

The capacitor is rated at 4 µF (microFarads) with a max voltage of 250V (@70C). A capacitor buffers current -- on each side of zero (since AC current goes from 0 -> 60V -> 0 -> -60V ->0). When circuit is high, will buffer positive and as switch goes negative, capacitor will bleed off and slow the change such that the peaks will be lessened and change will be slowed. The result: with less force generated by current changing direction more slowly, the hum will lessen, possibly becoming inaudible.

The fan unit I salvaged this from put the capacitor on the same 2 poles that led to the power switch in parallel with the switch.

If you need more specifics, google for details. With all the examples, you'll be in the best position to decide how much more detail you need.

Some recommend DC motors -- with a good DC current, they should also be quiet. But that's the trick: getting a good DC current --- since there are at least a few circuits that can do that -- so you could get hum from the AC->DC converter. Would have to research how to solve that, but from what some say even in this "thread", its sufficiently less as to be inaudible or quiet with many such motors.

Related: I found a great online ref for types of light-dimmer circuits that tells why some are good and some are bad at http://www.epanorama.net/documents/lights/lightdimmer.html. The author of that section has a whole site of electronic related info.

FWIW, I've found capacitors on fans that I found to have low-hum which is why a make a point of this cause, as you can have the tightest physical install of a lower vibration fan and still have the electrical problem.

Hope this helps...

Answer 15

I think it's just "luck of the draw" -- we paid to have 2 identical hunter fans installed. The one in my office is so loud we had to take it down ($90 down the drain for the installation) -- the other (same fan different color) is much quieter -- has a slight hum, but is "sleepable". Prior to that one I had paid to have a harbor breeze fan installed in that room -- another $90 down the drain -- as it hummed and pulsed. None of these fans have remotes or dimmers. We had several harbor breeze fans (with remotes or dimmers) in our old house that were silent -- I really want to get another fan for my office but I am paralyzed by indecision because I don't want to pay to have another fan installed just to have the same problem -- very, very frustrating. BTW -- the electrician who installed the 2 hunter fans said that fans with a DC motor were quiet -- but good luck finding one that you will like. The selection is very limited.

Answer 16

I have 3, 40 yr old Hunter fans that are absolutely silent. Bought a newer hunter fan because I wanted an led light and it hummed. Hunter replaced it with a more expensive one and it hums too. I agree with an earlier writer that it is the triac speed controls that are the problem and I don’t know if the problem is solvable. The 40 yr old fans change speed thru switching motor windings so you can’t use the fancy remote controls but I sure like them better. Of course, Hunter probably isn’t happy that they lasted 40 years and are still going strong