The ceiling fan/light fixture in my kitchen eats light bulbs. The light is on for a large part of the day, but it seems to go thru bulbs very quickly. We bought those fluorescent bulbs to help save money on electricity, the kind that’s supposed to last for years? They lasted maybe three months. In one of the “cans”, the bulbs sits almost against the side. I can see how that would cause problems, but all the bulbs (there’s four in the fixture) burn out quickly. My real question is could there be some wiring issue, or some defective part that is causing the bulbs to wear out faster?
My first thought was are you putting in the size (wattage) bulbs that are supposed to be in the fixture? Most fixtures, because of heat issues, have maximum wattages of either 60 or 100 and usually putting in bulbs larer than recommended can lead to reduced to life. Also are you using three or two ways bulbs and leaving them constantly on the same setting?
The other thing would be to try different brands of bulbs. The point is is that I don’t think you are describing a situation of bad wiring, which most likely would result in much shorter bulb live than what you are seeing now. You can check the wiring and make sure that it is correctly wired since that can be done (IIRC) without too much trouble.
The bulb package should have an average life expectancy printed on it. The typical light bulb is good for roughly 900 hours. At 10 hours a day that’s three months. At 24 hours a day it’s a little more than a month. If you have 25 bulbs in your house burning an average of three hours each day, a bulb will burn out every twelve days, on average.
If you compute the average life of your bulbs and discover it’s clearly less than the manufacturer’s rated life, then you may have:
You may have over-voltage in your house. Occasionally this causes more serious problems. You can get a cheap multimeter at Radio Shack. If the voltage is 125V or higher, talk to the power company about it. 7 or 8 extra volts on a 120V line will cut the bulb life expectancy in half. If it’s a slight over-voltage, you can buy special 125V or 130V bulbs, though sometimes they’re hard to find.
Too high a wattage bulb in too small an enclosed fixture (such as a globe), the heat can’t get out–the bulb burns too hot, leading to short bulb life.
Recessed lighting fixtures often get covered by attic insulation. This blocks the intended ventilation method–heat can build up around the bulb, causing short bulb life.
A vibration problem. Such as, bulbs under a heavily used stairway, on or near an out of balance bathroom or ceiling fan, or near a door that gets slammed, or kids upstairs jumping, etc. You can buy special shock resistant, also called “rough service” bulbs, for this situation, or try one of the new compact screw-in fluorescent bulbs.
Have you checked the voltage at the fixture and compared it to what the electric company says your line is supposed to be?
Since you’re losing incandescent as well as fluorescent bulbs, the culprit is probably not overheating. Also, since you didn’t mention any other bulbs in your home having a shortened life-span, it’s probably an not over-voltage issue. You didn’t mention whether the ceiling fan is running or not while the light is on, but that could be a source of vibration which would shorten the life of an incandescent bulb, but not so much a fluorescent. Unless the problem is a poor wiring connection which could be jarred by the ceiling fan’s vibration. This could easily shorten the bulb life.
A last possibility that bears inspection would be a high resistance connection somewhere in the wiring to the lights. Like any wire-nutted junction or switch connection or dirty switch contacts. Any such connection will be recognizable by a charring or discoloring of the wires in the area. If none of the other possibilities seem likely, I would check the switches and connection in the fan and wall switch. But I would do it very carefully after ensuring that all electrical power to the device was turned off at the breaker panel.
The bulbs are of the appropriate wattage, or lower. The fan runs, but not all that often, I don’t think that is connected. Checking th wiring and such will be my next step.
Thanks!
Philster has a valid point about over-voltage, and it will certainly eat into the life of an incandescent bulb. But I would expect fluorescents to be more immune.
One factor that eats light bulbs is the inductance of the wiring. If it’s laid out badly, there will be a large self-inductance in the circuit, and a huge back-EMF will be produced every time a circuit is switched off. This is often noticable as sparking from within the light switch as it is turned off - the large voltages produced will arc across the open switch contacts briefly.
Is it a dimmer switch? I’ve noticed this problem in my house. The previous owners wired almost everything as a dimmer. I’ve put CFs in every other fixture/lamp in the house. Those run A-OK. But when I placed a CF into the dimmer fixture in my kitchen, it burned out within a day or two. The voltage, I’m guessing, was not adequate, even when the switch was turned all the way up.
So that could explain your CF failure. Your incandescent bulb failure … beats me.
Lights on a fan die quicker because of vibration. There are bulbs for rough use, but they still don’t last as long as in a regular table lamp. It doesn’t matter if it’s fluorescent or incandescent they both contain filaments that break from vibration.