I don't think they'd be that distracting, honestly.

January 11, 2007 6:40 PM

The back window of my car has little defrosting wires running through it to keep it clear in snowy weather. Why doesn't my windshield?
posted by boo_radley to grab bag (21 comments total)

If your head goes through the windshield, do you want it to be sliced up into sections like a piece of cheese?
posted by MegoSteve at 6:41 PM on January 11, 2007 [1 favorite]

Probably because it would impair your vision of the road. Also, the windshield has defroster vents and wipers, both of which work faster than those little wires.
posted by bizwank at 6:42 PM on January 11, 2007

Some cars do -- the wires are thinner, but you can still see them.
posted by chrismear at 6:44 PM on January 11, 2007

Also, in my experience, my back windscreen with the wire heater clears up much faster than my front windscreen with just air vents, which must wait for the engine to warm up to be effective.
posted by chrismear at 6:45 PM on January 11, 2007

Wikipedia article on Ford's 'Quickclear' technology.
posted by chrismear at 6:51 PM on January 11, 2007

bizwank: practical experience says that the front vents and wipers do not work faster than the back window defroster.
posted by boo_radley at 7:00 PM on January 11, 2007

Megosteve: AIUI, the 'wires' are actually painted-on; if not, they're certainly very fine. They'll do a lot less damage to your head than the windshield itself will.

I'm guessing that once the engine is warm, using its waste heat to keep the windshield clear is a lot more fuel-efficient than using electric power.
posted by hattifattener at 7:01 PM on January 11, 2007

If your head even comes in contact with the windshield in a crash you've got much bigger problems than a bunch of teeny tiny little foil wires... so I don't think that really is a concern. The wikipedia article lists a lot of good reasons: prone to failure, expensive to replace, hinders radio/cell phone reception, and air vents already present at the dash.
posted by Rhomboid at 7:02 PM on January 11, 2007

Oh and you guys that are arguing which is faster: consider that the front windshield is directly in the path of one (and sometimes two) humans exhailing, which means warm, humid air, which is perfect for creating condensation on a cold surface. In other words, defrosting the windshield is a tougher task, so it's not fair to compare electric on the rear to air vents on the front.
posted by Rhomboid at 7:09 PM on January 11, 2007

Here's a handy list of cars with the feature. They're listed because they interfere with radio toll tags, so that's another con.
posted by smackfu at 7:24 PM on January 11, 2007

Rhomboid got it with the hot steamy breath. mmm... The defrost setting on any car not only directs hot air to the windshield(melting ice and snow) but activates the air conditioning to draw moisture out of the air inside the vehicle. Also, the defrost setting is the default position in a car's HVAC system. should anything go wrong, the mode doors should direct air to the windshield. There is NO backup plan when a rear window defroster grid fails. This is a safety issue.

I don't know what the acronym for this would be but, I am a certified master automobile and light truck mechanic.
posted by Paleoindian at 7:27 PM on January 11, 2007

Hmm. The air defroster on the windshield of my Saturn SL is faster than the rear window. The air defroster on the windshield of my Taurus station wagon is MUCH faster than the rear, and faster by a long shot than the Saturn.
posted by lhauser at 7:40 PM on January 11, 2007

Do you guys have air systems that generate heat independently of the heat generated from the engine? Because maybe that's where we're getting our wires crossed.

In my car, I have to wait a good five minutes or more before the engine's hot air, by which time the back window has cleared up completely thanks to the electric element.

And it's not my breath fogging up the front windscreen, because I'm outside the car scraping the ice off.
posted by chrismear at 7:42 PM on January 11, 2007

Ironically, if you weren't outside scraping ice (i.e. driving) the heater would start working much faster -- idling is about the slowest possible way to bring an engine up to operating temperature. If you can get moving, even just a little bit, it will greatly speed things up.
posted by Rhomboid at 7:56 PM on January 11, 2007

Ironically, if you weren't outside scraping ice (i.e. driving) the heater would start working much faster -- idling is about the slowest possible way to bring an engine up to operating temperature.

Perhaps chrismear should drive his first mile backwards to heat up the engine. Then that defroster will work just fine.
posted by peeedro at 8:03 PM on January 11, 2007 [2 favorites]

You can get windshields with electric defrosters on lots of cars, winterised Subarus, Saabs and that sort of thing. The wires run around the sides. They are great, until you break them which is a frequent occurance in cold places. Then they cost around $1500 to replace and they are distinctly less great.
posted by fshgrl at 8:21 PM on January 11, 2007

When you sit too close to a TV, you see the individual pixels, but from across the room you do not. Sitting 1' away from the wires used on rear windows would be very distracting, but when viewed from an effective distance of at least 3', and often 6' (when viewed through the rear-view mirror), they are not distracting.
posted by Chuckles at 10:09 PM on January 11, 2007

My Subaru has them, and not on the sides. There are located at the bottom edge, where they are not in my field of vision. The car is six years old and they work just fine.
posted by fixedgear at 2:36 AM on January 12, 2007

The ones on fixedgear's Subaru are there to thaw the wiper blades, which are supposed to park on that area. I have them, too. That area of the windshield is the first place thawed out by the defroster vents, so putting heater wires there does not speed up overall windshield defrosting much.
posted by Kirth Gerson at 6:26 AM on January 12, 2007

Cost is probably the reason you do not see them on the front. My vehicle has them. They were factory installed. They work wonderfully. For whatever reason I do not have a problem at the toll booth here in Atlanta. They are undoubtedly faster than the traditional defroster (about 75% faster in fact). They have been operating without fail for over four years so I have to say they are dependable. From a stand point of convenience and safety, if you are considering them, I would highly recommend them- regardless of the costly price tag.
posted by bkeene12 at 6:55 AM on January 12, 2007

I don't know what the acronym for this would be but, I am a certified master automobile and light truck mechanic.

Why, that would be IAACMAALTM of course
posted by Neiltupper at 9:16 AM on January 12, 2007