Building Construction, Renovation, Maintenance & Advice

Ceiling Fans

“My what a big big toe you’ve got”

"Yes it took me 40 years to develop that toe. It's worth a lot you know, I have it insured for 20,000 rupiah!"

Welcome to the British Raj, the era of digitus grandus. A time when the livelihood of whole families depended upon the earning power of the patriarch's right foot and a person's status was determined by how large their big toe was.

I am referring, of course, to the time of the Punkah Wallahs. The patriarch's big toe would be connected to a piece of string which went up to the ceiling and passed through a series of pulleys to a large horizontal fan known as a Punkah. When the toe pulled the string the fan blade swept across the ceiling to provide a draft.

As can be imagined the big toe was a much sought after commodity in the hot and sticky days of the British Raj when spotty public school types with plumby accents and names like Rupert were sent away by parentally fatigued mater and pater to seek fame and fortune in far off corners of the Empire. “Oh I say chaps, let's have a jolly old rumpus in the Raj.”

Those were the days before Oprah Winfrey had people crying about how their family had fallen apart because hubby kept passing wind during dinner and (horror of horrors) leaving the toilet seat up and the most exciting thing on television was "Songs of Praise" from the parish church of Little Upper Wallop. Sunday evening was always a special occasion. The whole nation would stop, transfixed, staring at the black and white image of the stern looking school ma'am Miss Nether Swipe wearing her Sunday best flowery hat, in full cry to a rousing rendition of "Onward Christian Soldiers" while next to her old Mr Wilcox, hymn book upside down, pretended to mouth the words and little Thomas Higginbottom picked his nose and wiped his finger on his blazer.

Hard to believe I know but in the Raj they didn't have television. “Toe Motion” brought luxurious comfort and people didn’t worry too much about electricity blackouts. A gin and tonic in the toe powered cool of a tropical evening was the height of colonial decadence.

Punkah Wallahs have been put out of work

It used to be that way but, sad to say, these days that new fangled electricity stuff has put many toe advantaged people out of work. The Punkah Wallahs have now gone and the only memory is the term “punkah louvre”, the name given to the cool air outlets above the seats in aircraft (now there's a bit of totally useless information for you, interesting - maybe, but useless nonetheless).

The punkahs, of course, have been replaced by the ceiling fan, that ubiquitous piece of electrical wizardry that sits forgotten on the ceiling and makes life bearable all over the tropical and sub tropical zones of the planet by cooling your room.

Actually that's not quite right. The cooling effect of ceiling fans (and punkahs for that matter) is achieved not by blowing cool air to cool the room but by blowing air over your skin, this increases the evaporation rate of perspiration so making your body's natural cooling process work better. A diaphoresis invigorator so to speak. You might as well turn the ceiling fans off if there's no one in a room.

How much power does a ceiling fan use?

Mostly our ceiling fans are out of sight and out of mind but then, one day, they go wrong and we are reminded how useful they are. Surprisingly they very rarely do go wrong and, you may be pleased to know, they also use very little electricity (around 65 watts or about the power consumption of a medium sized standard light bulb).

They are a simple but cleverly designed device, an electric motor hanging on a pole with 3, 4, 5 or even 6 fan blades fastened directly to the motor. No gearbox and very little to go wrong. The secret of the ceiling fan lies in the fact that the rotor is heavy and acts as a flywheel. It takes a while for the motor to get turning but once it has got up to speed there is a lot of momentum in the flywheel and the motor doesn't have to work hard to keep it moving.

It takes more energy to start a ceiling fan than it does to keep it turning (funny that). If you remember in the recent article "Danish Bacon" (click here) we talked about how electrons zipping through wires make electric motors turn.

In a ceiling fan you may (depending on the design) have 2 different windings of copper wire in the motor, one (the main winding) to provide the power to keep it turning and a second (auxiliary winding) which is needed to get it started.

Ceiling fans need a capacitor to start the fan moving

Another important component in a ceiling fan is a capacitor. Simply speaking a capacitor is an electrical device that stores up electricity then releases it as a sudden burst of energy. The capacitor works with the auxiliary winding to provide a kick start to get the fan turning. Capacitors are also used to start flourescent lights, in photographic flash guns and in air conditioners.

If your ceiling fan won't start (you may hear it buzzing but it won't start moving) it could well be the capacitor. Try pushing the blades to start the fan turning, if the problem is the capacitor the fan may carry on running normally once you have manually started it.

You can do a similar trick with a flourescent light by stroking along the length of the tube with your hands, this generates static electricity which can “zap” the tube and get it started if the capacitor isn't working properly. Sorry I don't have a trick for an air conditioner but a rather large hammer may provide a somewhat cathartic experience and a short lived (though rather expensive) emotional release.

There are various different ways of controlling the speed of a ceiling fan and how these work is a little too complicated to go into here. I sense your brain is starting to glaze over but suffice it to say the speed controller should match the fan and it is best to use the speed controller supplied with the fan.

Earlier fans may have pull chains or rather large wall mounted rotary switches while these days there are some smart looking solid state rotary speed controls and even remotely controlled fans.

Light dimmers should not be used as fan speed controllers

Take care. The solid state rotary speed controls look very much like light dimmer switches but they are not the same. It is important to note that you should NOT use a light dimmer to control a ceiling fan. There are a number of people around who may call themselves electricians that may not know the difference.

If you do want to use a smart modern speed control for your fan it is best to buy a high quality unit specifically designed for the job.

For safety ceiling fans should be earthed (grounded)

Fans are driven by electric motors and so may use more peak power than lights and will need to be earthed (grounded). You shouldn't use existing lighting wiring to power a ceiling fan, you will need a higher rated 3 core cable.

Ceiling fans should have a strong mounting

You also need to think about how the fan is mounted to the ceiling. Remember a fan can be quite heavy and don't fly very well even though they are pushing air downwards, you don't want the fan to come loose during the kid's christmas party or you may well end up with a ceiling fan massacre. You need to make sure the fan is securely fastened to a reasonably substantial beam in the ceiling.

Take very careful note of the height of the fan. As Marie Antoinette found out, thin pieces of steel travelling at speed can remove even a robust sense of humour rather quickly. Exuberant fathers throwing their babies in the air under ceiling fans have caused more than a few tragedies around the world. You need to make sure that the fan blades are higher than baby tossing height ie. a tall man with his arms outstretched. Some people say 7 feet, I would say significantly higher to be safe.

A wobbly ceiling fan needs to be balanced

A ceiling fan should spin smoothly particularly at higher speeds. If the fan wobbles (and many do) it means that the fan is out of balance. Two things can put the fan out of balance: variation in the weights of the fan blades or variations in the position the blades are bolted on to the fan hub.

If your fan does wobble first check that the fan is clean, and that the blades are in good condition. Rusting of blades, different amounts of paint or even a wasps nest can make the blade weights vary. You can try removing the blades and then reinstalling them in different positions on the hub. If this doesn't work you can try adding small amounts of weight to the blades to get them back into balance. You might try a blob of chewing gum or blutak stuck on the end of the blade but it may take a bit of experimentation to (a) find the right blade and (b) get the right amount of weight added.

Rusting fan blades - a perennial problem

Some time ago I went to see a very nicely finished group of villas situated right on the beach. The living rooms were all finished in powdered palimanan stone which gave a beautiful natural finish to the rooms, but - each room had a brown line around the walls a metre down from the ceiling.

Examination revealed that the lines were caused by two ceiling fans in each room that had steel blades. Being exposed to constant sea breezes the blades had rusted and sprayed a line of rust around the room.

Nothing could be done about the walls. Palimanan is notoriously absorbent and once stained could never be cleaned. Attempting to repair the stained line would have shown badly however hard you tried. A very expensive luxurious wall finish had been destroyed by a stupidly simple but very common problem - rusting fan blades.

Ceiling fans come in many configurations and designs but most are basically the same. They are low cost, mass produced items and the vast majority have pressed steel blades finished with a coat of paint. Spinning continually through the air the paint on the leading edges of steel blades tend to fail fairly quickly and the blade starts to rust.

Most of the ceiling fans that are supposedly made from stainless steel also rust fairly quickly and in fact are not stainless steel at all but ordinary mild steel with a plated coating.

Drooping fan blades

This is not an easy problem to solve, it is not easy to find fans that have blades that don't rust unless you go for wooden blades. Many of the “colonial” style fans with brass centres and what at first glance appear to be wooden blades are not wood but a composite. They might not rust but they do tend to droop after a while.

If you hunt around you may be able to find fans with genuine stainless steel or wooden blades. Ceiling fans are generally very cheap items and it is worth paying a bit more for one that will last.

Failing that you could always get yourself a punkah and see if you can find someone with an oversized big toe who, for a few shekels, wants to pull a string all day long. I suspect you'd have more chance of teaching your dog to tap dance.

Copyright © Phil Wilson 2011
This article or any part of it cannot be copied or reproduced without permission from the copyright owner.

17 July 2017 Copyright © Mr Fixit,
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