Thank you, Watts law...

[billygoat22]

Was at the made in China store yesterday at checkout. guy behind me pointed to a 12v "windshield defroster" and commented on it.

He got it for one of his vehicles, but said it didn't work too well.

I picked it up and no watt output listed on it like most elec htrs have.

I pointed out to guy that 12vdc and 13A come out to about 150W. "I might as well lay a light bulb on dash then", he says.

Maybe it works better in a smart car? I joked. You can't run it all night to warm car, would kill battery, so what good is it?

[jpsmith1cm]

http://www.ask.com/wiki/Placebo?qsrc=3044

[corny]

Get a block heater..... still gotta start the car but it warms up faster.....

I just scrape my windshield...... turn the truck on and scrape it off real quick......

Of course.... my fan doesnt work till I drive down the road and get it up to about 50..... with temp dial set to cold..... guess it opens something up to get some wind across the fan..... sometimes I can take my hand and bump the fan housing and get it to work...... but regardless.... I still go ahead and scrape the windows.

[ammoniadog]

You can't run it all night to warm car, would kill battery, so what good is it?

By this logic, no car should have anything that won't work all night long when the engine isn't running. Certainly not a defroster, heater, or air conditioning. What's the point of anything?

Actually, I think the point of those things is to try to help if your vehicle's hvac fan takes a crap. I had one of those in one of my first vehicles when I was about 16 or so. I have to agree with that guy, in that they really don't work worth a crap. If you ever are in the need for one of those things, I think you'd be better off saving your money and hanging your head out of the window (which I've had to do plenty of times back then).

[HVAC_Marc]

everyone should have an electrically heated windshield. hop in, turn the key, hit a button, and 1/4" solid ice disappears in 3 minutes. easy peasy.

[ammoniadog]

everyone should have an electrically heated windshield. hop in, turn the key, hit a button, and 1/4" solid ice disappears in 3 minutes. easy peasy.

Hell, I'd settle for diffusers that were actually aimed at the windshield in a way that made sense. You know when part of your wiper freezes up and then you only have a tiny part of it that actually touches the windshield, and then you need to hang out the window and try to grab onto the wiper while it's moving and smash it against the windshield a few times? This could easily be avoided if the manufacturer would have lined up the diffusers to go underneath the entire length of the wiper blade. I know that in the Ford vans at least, the slots are offset and staggered in a way that leaves part of the wiper blades without air blowing under them. They've been making vehicles for a little over 100 years, but they can't figure out simple stuff like this yet.

[DeHeatify]

I've seen higher end cars with the defrost strips layed on the window under the wiper blades.. That seems like a good idea to me.. Same function as the rear defrost.

[rjk_cmh]

Some European car manufacturers are already developing CO2 A/C systems for cars because of F-gas regulations, and one of the cool things about such a system is INSTANT HEAT from the condenser when you start it up. They are using that heat to defrost the windshield in winter, which is an awesome idea.

[billygoat22]

By this logic, no car should have anything that won't work all night long when the engine isn't running. Certainly not a defroster, heater, or air conditioning. What's the point of anything?

Actually, I think the point of those things is to try to help if your vehicle's hvac fan takes a crap.

You don't need to run the lights, a/c, defroster or heat all night for it to work in the morning, which would kill the battery. But the output of the battery heater is so small, it would have to be kept on all night to keep some heat in the glass if any hope of clearing off fog in morning, which defeats the purpose if the battery is dead and car won't run/ heater is cold.

[billygoat22]

heated mirrors are pretty cool, too.

[54regcab]

The block heater is actually the most effective way to get the vehicle warm quickly.

[HVAC_Marc]

The block heater is actually the most effective way to get the vehicle warm quickly.

unless you have a catalytic auxiliary heater