Purpose of Coated Windshield

[mknox]

I am curious about the Model S coated windshield (the one that is causing problems with EZ-Pass, Door Openers etc.) and wondering what the coating is for.

A few years ago I recall (I think) Lincoln used a coated windshield that was blocking RF like this. In that case, the coating was conductive and used for front defrosting. I noticed that there does not seem to be a front defroster vent on Model S (there is what looks like a speaker grill across the bottom of the windshield) and so wonder if that is the case here? If not, I'm not sure how you would get ample airflow across the windshield from a "standard" defroster.

[ElSupreme]

I believe that the coating makes the glass very reflective to IR light (aka heat). So it keeps the interior of the car much cooler, and lowers the load on the HVAC.

It would also effectively keep heat in the car when very cold outside.

I am not 100% sure this is the reasoning.

[mknox]

I believe that the coating makes the glass very reflective to IR light (aka heat). So it keeps the interior of the car much cooler, and lowers the load on the HVAC.

There are indeed themal coatings, but I just wondered, with what appears to me to be a lack of defroster vents, if it might be heated glass.

[MikeK]

My RAV4-EV has a heated windshield. It doesn't seem to bother EZ Pass, but man is it great for defrosting.

[pete8314]

My RAV4-EV has a heated windshield. It doesn't seem to bother EZ Pass, but man is it great for defrosting.

not the same thing, but yes, they're great for defrosting, cost a lot of money to replace if you happen to break one though, and have to pay full price for a new screen!

[donauker]

There are indeed themal coatings, but I just wondered, with what appears to me to be a lack of defroster vents, if it might be heated glass.

Actually the "speaker grill" is the defroster vent. Lots of noisy air when you hit the defrost button.

[mknox]

Actually the "speaker grill" is the defroster vent. Lots of noisy air when you hit the defrost button.

Well, I guess that answers the question of the front defroster... thanks.

[MikeK]

not the same thing, but yes, they're great for defrosting, cost a lot of money to replace if you happen to break one though, and have to pay full price for a new screen!

I was replying to mknox, who specifically mentioned heated glass.

I totally agree that they are expensive. I think for the RAV they're around $1000.

[Johan]

I drove a Ford (Focus?) once with defroster in the front windshield. To me it was disturbing since I could (barely) see the zig-zag shaped lines in the windshield (the heating wire that is).

[spatterso911]

I drove a Ford (Focus?) once with defroster in the front windshield. To me it was disturbing since I could (barely) see the zig-zag shaped lines in the windshield (the heating wire that is).

You get used to it fairly quickly though. They are present in my wife's LR3