By Arrol Gellner
The late humorist James Thurber once wrote about an aunt of his who had some profound misconceptions about technology. Among other things, she was convinced that electricity leaked out of empty light sockets.Nowadays we like to think we're much hipper to such things, but judging by some of the questions I've hear from clients, I suspect we all still have a bit of Thurber's aunt in us. To wit:
- If I turn the thermostat all the way up, will my house heat up faster? Alas, no. The typical thermostat is really just an on/off switch; it's activated by a bimetallic spring that responds to changes in temperature. Since it can't do any more than turn the furnace on or off, setting the thermostat to 90 degrees won't warm things up any faster.
Incidentally, this goes for ovens as well. It'll take just as long to reach 350 degrees whether you turn the thermostat to 350 degrees or 500. - My refrigerator is supposed to cool things, so why does it give off warm air? A refrigerator works by compressing a special gas called refrigerant. The gas gets hotter when it's compressed, just as the air in a bicycle pump gets hotter. The heat from the compressed refrigerant is dissipated into your kitchen by a fan coil, which is where the warm air comes from. But here's the neat part of the process: When the compressed gas is allowed to expand again, it tries to regain its lost heat by absorbing it from other objects - in this case, that warm six-pack you just put in the fridge.
- Fuse, circuit breaker, GFI - what's the difference? A fuse is a device used to prevent too much current from flowing through a wire of given size, because when that happens the wire gets hot - and as Jesse Jackson might say, hot wires start fires. Fuses are found in most houses predating World War II; they consist of a screw-in socket enclosing a thin strip of metal. When the metal carries more current than the rating of the fuse, it melts (or "blows") and the circuit is broken.
The problem with fuses has always been their multifarious ratings - 10 amp, 15 amp, and so on. When a fuse blew, no one ever seemed to have the right replacement on hand. So they'd cheat by substituting a fuse with a higher rating (or worse yet, a copper penny), occasionally burning down the house in the process.
The inconvenience and frequent misuse of fuses brought us the circuit breaker. It's essentially a switch that serves the same purpose as a fuse, except that when it "blows," you simply reset it - hopefully after correcting the condition that made it trip.
GFIs, or Ground Fault Interrupters, are little electronic devices quite capable of saving your life. Suppose you like a little thrill now and then, so you decide to blow-dry your hair while you're still in the tub. Oops! You dropped the hair dryer in the suds! In milliseconds, the GFI-protected receptacle you wisely installed in your bathroom senses that 120 volts is about to take a detour through your body, and it shuts off the current.
Cheap and amazingly effective, GFI protection is now required by code for any receptacle within 6 feet of sinks, lavatories or other water sources, as well as in garages and at outdoor receptacles.
And by the way, electricity doesn't really leak out of an empty light socket. However, you can still fry yourself if you stick your finger in one - so keep a bulb in it for safety's sake.
. Questions of a Do It Yourself nature should be submitted to our "