glass roof - production change (July 2018)?

[ℬête Noire]

I suspect that polarization plays a role. No polarization is advertised a feature of some optical filter glass.

That could be, water droplets will create visual "rainbow" effects when combined with polarized optics (like the view through some polarized sunglasses). There could be some stuff happening with light getting distorted by the droplets that leads to a polarized reflective surface creating that visual effect.

 

[animorph]

I would think absorptive would make the glass hotter than reflective.

 

[ebmcs03]

I would think absorptive would make the glass hotter than reflective.

From post 519:

Heat absorbing glass is used to reduce the amount of heat transmitted through an optical system. Filter glasses effectively absorb wavelengths beyond the visible spectrum. Unlike hot mirrors, which reflect the infrared wavelengths, Filter glasses absorb the infrared radiation and then dissipate the heat into the air around the glass. Filter glasses can also be utilized as a shortpass filter, in order to pass the visible and block the IR.

 

[ℬête Noire]

I would think absorptive would make the glass hotter than reflective.

The glass being hotter doesn't necessarily mean the inside, what you actually care about as long as you don't put your hand on the glass, is hotter as long as the radiation of that extra heat is managed appropriately. The net result can still be, as they are claiming, the same thermal properties.

Or at least approximately, averaged over all situations. One thing about the heat blocking being absorption is that you'll tend to get a lot better results when the vehicle is in motion, as air passing by on the outside is usually an opportunity for more conduction of heat into it (as long as the outside air is cooler than the glass itself, which will usually still be the case on sunny days).

 

[remlemasi]

I would think absorptive would make the glass hotter than reflective.

I agree.

Yesterday, I got into my car, which had been parked in the shade, and felt a good amount of heat from the sun baking my head. I have tint on the roof glass so I was concerned that it wasn’t doing its job.

I felt the glass and it was hot to the touch, at which point I realized the heat radiating from above was not from the sun, but from the glass itself, which had absorbed a large amount of heat.

To confirm my hypothesis, I drove into a covered parking structure and felt absolutely zero decrease in the heat radiating into my head. Same as when the car was sitting in full sun.

I can imagine that the change from a IR reflective method of heat rejection to an absorptive one would make matters worse.

 

[remlemasi]

The glass being hotter doesn't necessarily mean the inside, what you actually care about as long as you don't put your hand on the glass, is hotter as long as the radiation of that extra heat is managed appropriately. The net result can still be, as they are claiming, the same thermal properties.

Or at least approximately, averaged over all situations. One thing about the heat blocking being absorption is that you'll tend to get a lot better results when the vehicle is in motion, as air passing by on the outside is usually an opportunity for more conduction of heat into it (as long as the outside air is cooler than the glass itself, which will usually still be the case on sunny days).

See my post above. I don’t necessarily disagree with your statements, but for a car parked in the sun (no air flow above the glass roof as you pointed out), it makes a difference. The heat radiating from the hot glass is very noticeable.

 

[ebmcs03]

See my post above. I don’t necessarily disagree with your statements, but for a car parked in the sun (no air flow above the glass roof as you pointed out), it makes a difference. The heat radiating from the hot glass is very noticeable.

Are you talking about the glass on top of the front seats or rear seats.

If you have both types of glass (since the front is the orange reflective type) can you measure the heat between the two types and see if the new non reflective glass is any hotter than the front?

 

[ℬête Noire]

See my post above. I don’t necessarily disagree with your statements, but for a car parked in the sun (no air flow above the glass roof as you pointed out), it makes a difference. The heat radiating from the hot glass is very noticeable.

You still need to measure the net amount transmitted with the old glass versus the new glass to assess whether it's better or worse overall. Just saying "there's heat radiating off this glass" doesn't do that.

P.S. In the winter time though the adsorption based glass is going to give better results, because BEVs care a lot more about having to create heat.

 

[remlemasi]

Are you talking about the glass on top of the front seats or rear seats.

If you have both types of glass (since the front is the orange reflective type) can you measure the heat between the two types and see if the new non reflective glass is any hotter than the front?

My anecdote above was sitting in the front seats, but I also have full IR reflecting orange tint on the rear glass. I also imagine that my aftermarket tint is also contributing to the heat absorption and the requisite radiation

You still need to measure the net amount transmitted with the old glass versus the new glass to assess whether it's better or worse overall. Just saying "there's heat radiating off this glass" doesn't do that.

P.S. In the winter time though the adsorption based glass is going to give better results, because BEVs care a lot more about having to create heat.

Yep, I'm not commenting on old reflective versus new absorptive rear glass. Just generally stating that absorption does play a large role in how much heat is transferred into the cabin, especially when parked with no convective air flow to cool the glass.

For all we know, the practical differences of old vs new rear glass is negligible, but just wanted to clarify that the percentage of heat transmitted through is not the only factor. How it's rejected (reflected vs absorbed) does play a role, even if small.

P.S. interesting note on winter driving!

 

[MissyMcBee]

My car was built July 6, 2018 and while it's pretty i'm not sure it means it's as functional... i'm more concerned that my back glass sits about 1/16 inch higher in the middle as it meets the top glass...

 

[brianmeow]

As much as I appreciate the direct message to me telling me you’ve reported me, that doesn’t stop the fact that you are derailing any honest attempt to have this discussion on the forum.

And to answer your question - no. I’m not doing it for the clicks and likes. Good lord.

Edit: I enjoy the projection of “do you do it for the likes?” Followed by you disliking/liking just about everything.

Back on-topic: I’m excited to hear about what people report back with from Tesla proper. Interested to hear if any service delivery appointments come back with different glass than was delivered. Wondering if future sunroof glass is going to do away with the color tone, too, and we’re just in an inbetween phase.

He private messaged me also saying he reported me and mods had removed tons of his posts already from this thread alone.
Back on-topic: I'm going to follow up with my service center regarding the confirmation from Tesla about removing IR coating. I don't like how they just decided to make the change without telling customers or service centers.

 

[chronopc]

I sprayed water on my back glass and it looks like the orange stops where the lines start. Do I have a defect?

 

[ℬête Noire]

Do I have a defect?

I can't and won't speak to that, but sounds like the glass is fine. This was a planned but unannounced change in parts. As Tesla does. ¯\_(ツ)_/¯

glass roof - production change (July 2018)?

 

[MP3Mike]

I don't like how they just decided to make the change without telling customers or service centers.

You may not like it but that is what Tesla has always done, and will continue to do. Like when Model S cars started getting lighted vanity mirrors, or the change from MCU1 to MCU2 in the S&X, or the change from Alcantara to the current premium textile headliner in the Model 3, or the change to the V2 front seats in the Model 3, or the V2 rear seats in the Model 3, or the redesigned windshield on the Model 3 to reduce wind noise, or any number of other changes to improve the car or reduce costs.

 

[brianmeow]

You may not like it but that is what Tesla has always done, and will continue to do. Like when Model S cars started getting lighted vanity mirrors, or the change from MCU1 to MCU2 in the S&X, or the change from Alcantara to the current premium textile headliner in the Model 3, or the change to the V2 front seats in the Model 3, or the V2 rear seats in the Model 3, or the redesigned windshield on the Model 3 to reduce wind noise, or any number of other changes to improve the car or reduce costs.

but this change wasn't just some cosmetic change/downgrade, it might have potential heat rejection issue for the car. I'm worried because i put my baby girl in the backseat everyday.

 

[ebmcs03]

but this change wasn't just some cosmetic change/downgrade, it might have potential heat rejection issue for the car. I'm worried because i put my baby girl in the backseat everyday.

Better get some good tint then. To be honest I don’t think the new glass is any worse at heat rejection. It still protects the occupant from all the UV rays, which is more of a concern. Concerned with heat. Turn on the AC.

 

[brianmeow]

Better get some good tint then. To be honest I don’t think the new glass is any worse at heat rejection. It still protects the occupant from all the UV rays, which is more of a concern. Concerned with heat. Turn on the AC.

For sure i will get some good tint for the whole car, as soon as i get the car back from SC for paint defects. I'm new to tint, what's a good tint for the roof?

 

[ebmcs03]

For sure i will get some good tint for the whole car, as soon as i get the car back from SC for paint defects. I'm new to tint, what's a good tint for the roof?

Seems like Llumar Stratos series is good. 35% or 40%
Formula One Pinnacle Window Tint | LLumar

Here is the spec sheet
http://cdn.llumar.com/drupal/formulaoneautomotivespecifications2018september.pdf

 

[TEG]

I sprayed water on my back glass and it looks like the orange stops where the lines start. Do I have a defect?

No, I think a lot of us got that type of glass too.

It seems they have at least 3 types of rear glass:
#1: "Orange reflective" coating on whole window.
#2: "Orange reflecting" coating on only front ~2/3.
#3: No "orange refelctive" coating at all.

You can see the "2/3" coating on my car and another car in this photo:

 

[jay2]

from Tesla Model 3

For those of you wondering about the loss of iridescence on the rear glass on newer VIN's when wet, here is what I heard back from service:

"We have reached out to engineering in regards to the rear glass concern with the orange hue when wet, as we have seen the difference on the 3’s on our lot. There was a production change with the rear glass where they removed the IR reflection film from the glass and this is what is causing the coloring change when wet. The new glass itself has the same thermal properties as the old one and is more absorptive."

I am assuming the roof glass will follow suit once stock runs out.

If you have and like the iridescence, better be careful with your glass!