"Ceiling fans instead of AC?"
Column #844 4/30/2011
On The Level
Q. We going to try to avoid air-conditioning this summer for as long as we can to help with the electric bill. We have ceiling fans in each room-- a total of five in all. How should we keep the windows? We usually keep the windows open about six inches at the bottom. We recently noticed squeaking in one of the fans. Is there some sort of maintenance we should do for lubricating the motors? Should we leave them on when we are gone from the house?
A. Some people don’t like air-conditioning and many of us grew up in houses without it but have become addicted to it in adulthood. I confess I am one of those. People who avoid the use of A/C will be saving money on their electricity bills for sure as running even five ceiling fans most of the time will certainly use less electricity than will operating a central air-conditioning system.
The old-fashioned ceiling fans used to have little spring-loaded lubrication ports located somewhere along the main shaft into which once in a while you'd stick some light machine oil like 3-in-1 Oil or some sewing machine oil. The down side of this system was that some never lubricated their fans and the bearings wore out prematurely while others over did it and oil would splatter.
We now live in age of sealed bearings intended to be self-lubricating for the life of the fan. The life of the fan means the length of time it takes to wear out the non-replaceable brushes in the motor itself. Of course, fan life is a function of hours of use, so a fan that only gets a few hours of use a month will obviously last longer than one that is used constantly. As a point of reference, I have a friend who left a ceiling fan in his home run constantly for seven years. It was still working when he sold the house.
Ceiling fans are supposed to be mounted into electrical boxes that can resist 35 pounds down pressure. Common ceiling light fixture boxes can't do that. Millions of do-it-yourselfers have converted ceiling light fixtures to lights with tropical fans. They are especially popular in older homes with no or little air-conditioning.
I see marginal fan installations all the time but they usually give some small warning that they are about to fall down, like a bulge around the box in the ceiling. They now sell fan friendly retrofit mounting boxes specifically designed to convert a light fitting to one that can safely hold a fan. What I do see more often than not with amateur installations is the blade height being too low, creating a hazard for tall people's heads and most people's arms. Blade height is supposed to not be less than seven feet from the floor.
The squeaking that you're hearing is probably coming from one of a couple of possible contact points. Up where the fan connects to the ceiling is a shaft that attaches to the ceiling mount with a joint that looks like a knuckle or universal joint to allow fan movement should the fan be slightly out of balance. The joint is there so the fan will not transfer the energy of being out of balance to the mounting box that could ultimately cause the mount to loosen and the fan to fall down. It is not normally lubricated after installation and it may squeak with slight movement over time.
You can expose this joint by unscrewing the ring-nut on the shaft that holds the trim cover in place and pull the cover down which exposes all the connections. You can squirt a small amount of an aerosol spray lubricant (WD-40) on the joint. Don't over do it but a little hitting the wires won't hurt anything.
Look around at the fan-blade arms and see if any of them touch the motor chassis while turning causing a little noise. Spray there too. While you’re up there, wipe the leading edge of the blades that collect dust during operation and never reverse the blade direction without cleaning the blades first or you’ll experience a little dust blizzard as the blades shed dust on their own.
If the fans are working fine, not making any ominous buzzing or loud humming noises or not threatening to fall down, then leaving them on low while you’re not at home should be safe enough.
However, fans don't lower the temperature of the air, they just move it which makes warm air feel cooler when it hits our skin. That’s why fans are recommended to blow down in summer so you’ll feel the air. So in the spirit of electrical conservation, why leave them on when no one can feel them? As for having the windows open or not, I’d watch the outside temperature and compare it to the inside temperature. When it gets hot in mid-day in the 90s outside, you might notice it’s not that hot in the house. Then I’d close the windows to keep the cooler air inside. Then, after sundown when things begin to cool some, open them back up. That’s what Mom did.
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