Insulate Your Glass Roof - Improve Comfort, Efficiency

[UnsungZero_OldTimeAdMan]

I live in a place where it is super hot and sunny, and when it gets hot, it gets 45'c/113f+
I'm hoping by the time R2 gets to Australia, a simple, plain, metal insulated roof would be an option

Next to nil.

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[Sportstick]

I live in a place where it is super hot and sunny, and when it gets hot, it gets 45'c/113f+
I'm hoping by the time R2 gets to Australia, a simple, plain, metal insulated roof would be an option

Completely understand, empathize, and agree! But, it's not just there...we can beat you on occasion at 120F!

 

[Oldcarguy]

Interesting thread.
I really enjoy our glass roof. Our grandchildren love it. They have been know to complain when they are in a vehicle without a glass roof.
I have had sunroofs and moonroofs in several of our vehicles over the years and have hardly ever opened them. They require more maintenance than our glass roof in the Rivian. I would be interested in looking into tinting the windshield. Mainly for cutting down on oncoming headlight glare.
The insulation and cover project was well done. I can see where it could be useful if the glass roof bothered you.

 

[2kwik4u]

I really wish they would have had a sunroof that opens as well as a drop rear window in the R1T - like my Sportrac had.

My Sierra has an opening roof and rear window. This side of a full convertible, there is no better solution for great ventilation. Especially in the shoulder seasons when you want that really pleasant air circulating through the cabin. Pop the sunroof up, and crack the rear glass and you got the amazing flow of air. Could even leave it like that in poor weather without getting the interior wet. Great for winter where you want some cool air on your head, but need to run the defrost to keep the windshield warm.

I should really look into another truck like that. I miss that a lot......guess this is the car guy equivalent of "I should call her"

 

[sealsinspace]

I feel obligated to contribute a reply to this thread, since I benefited from it (or tried to). We live in SoCal and don't have a garage or covered parking so keeping the summer heat out of the car is a priority.

We have an R1S and got the twraps UV&IR sunroof protection film for both roof windows back in March, hoping for improvement starting this summer (i.e. around now). Now that the days are heating up, I'm disappointed to say that we have not observed any improvement. Granted, I was not able to collect temperature data at the same time of day for the same outside temperature with and without the film, and that data is important, so take this with a grain of salt. This conclusion is based only on touching the sunroof glass with my hand. When the roof windows are fully lit on ~85 deg days, they are still blazing hot (far hotter than the cabin itself) and I cannot leave my hand on it for more than a second or two, even with the film. It feels the same as it did last summer. (And yes, I did put the film on the *topside* of the windows

Hope this is helpful. Not sure if the film is only helping by a couple of degrees, or I got a bad lot, but I'd recommend thinking twice before spending > $400. (Or at least reading posts that have measurements that are applicable to your situation.)

 

[twraps]

I feel obligated to contribute a reply to this thread, since I benefited from it (or tried to). We live in SoCal and don't have a garage or covered parking so keeping the summer heat out of the car is a priority.

We have an R1S and got the twraps UV&IR sunroof protection film for both roof windows back in March, hoping for improvement starting this summer (i.e. around now). Now that the days are heating up, I'm disappointed to say that we have not observed any improvement. Granted, I was not able to collect temperature data at the same time of day for the same outside temperature with and without the film, and that data is important, so take this with a grain of salt. This conclusion is based only on touching the sunroof glass with my hand. When the roof windows are fully lit on ~85 deg days, they are still blazing hot (far hotter than the cabin itself) and I cannot leave my hand on it for more than a second or two, even with the film. It feels the same as it did last summer. (And yes, I did put the film on the *topside* of the windows

Hope this is helpful. Not sure if the film is only helping by a couple of degrees, or I got a bad lot, but I'd recommend thinking twice before spending > $400. (Or at least reading posts that have measurements that are applicable to your situation.)

Thanks for sharing your experience, and credit to you for noting upfront that you didn't have controlled measurements — that actually matters a lot here, because what you're describing is expected behavior rather than a sign the film isn't working.

The film is designed to reduce the solar energy transmitted *through* the glass into the cabin (the spec is Total Solar Energy Rejected, or TSER). What it can't do — and no film can — is keep the outside surface of the glass cool when it's sitting in direct sun. Any clear pane absorbing sunlight on an 85°F day will reach 140–160°F regardless of what's on it. In fact, an IR-reflective film tends to make the *topside* run a few degrees hotter than naked glass, because energy that used to pass through into the cabin is now being absorbed and reflected at the film/glass layer instead. That's the film doing its job, not failing.

The other thing to keep in mind: unless every window on the car is tinted to a similar spec, you're not isolating the sunroof's contribution. Solar load is still coming in through the windshield and side glass, and that load alone is enough to keep the cabin hot. Treating only the sunroof and then measuring overall cabin temperature is a bit like insulating one wall of a house and expecting the whole place to feel cooler — the math just doesn't work that way.

Where the film *does* show up clearly is in cool-down: with less solar energy reaching the cabin through the roof, your A/C has less heat to remove, so it reaches your set temp faster and pulls less power doing it. On an EV that's also range you keep. The meaningful tests are (a) cabin air temp at headliner height after a fixed soak, (b) underside-of-glass temp with an IR thermometer, or (c) time-to-cool from a hot soak to a target temp. Touch-testing the top is essentially measuring solar load on a glass surface, which is the same with or without the film.

 

[Dasoss]

I feel obligated to contribute a reply to this thread, since I benefited from it (or tried to). We live in SoCal and don't have a garage or covered parking so keeping the summer heat out of the car is a priority.

We have an R1S and got the twraps UV&IR sunroof protection film for both roof windows back in March, hoping for improvement starting this summer (i.e. around now). Now that the days are heating up, I'm disappointed to say that we have not observed any improvement. Granted, I was not able to collect temperature data at the same time of day for the same outside temperature with and without the film, and that data is important, so take this with a grain of salt. This conclusion is based only on touching the sunroof glass with my hand. When the roof windows are fully lit on ~85 deg days, they are still blazing hot (far hotter than the cabin itself) and I cannot leave my hand on it for more than a second or two, even with the film. It feels the same as it did last summer. (And yes, I did put the film on the *topside* of the windows

Hope this is helpful. Not sure if the film is only helping by a couple of degrees, or I got a bad lot, but I'd recommend thinking twice before spending > $400. (Or at least reading posts that have measurements that are applicable to your situation.)

It is a common misconception that heating from sunshine is caused by infrared. Actually it comes from all wavelengths. The window films blockescaping. But pass other wavelengths that heat surfaces on the interior. These surfaces wil then emit infrared radiation The film blocks the infrared from internal surfaces from escaping. So the film can make things worse, except in cold weather. The glass gets hot because the film absorbs solar radiation rather than reflecting it. Reflective film would be a solution except that mirrored car windows are prohibited in most places. Reflective film on the roof might be ok. Most of the solar heating comes through the windshield and front side windows, so chabges to the rest of the windows may be insignificant.
.

 

[mkhuffman]

The solution I posted in the OP cost about $60 + the cost of the sunshade (there are multiple brands to choose from).

It seems to be working great except for one thing: the insulated wrap adhesive isn't strong and I have found it is detaching from the glass. It does not fall down because the sunshade catches it, but some parts of the wrap are separating from the glass.

I might try some adhesive tape to get it to stay. That will probably work.

If the glass is hot to the touch, it is radiating heat into the cabin. 100%. Covering it with something like what I did to block the radiant heat will definitely reduce the heat coming into the cabin. Film is not an insulator. It works by blocking light, but if the glass is hot, it cannot block that. The answer is to put some insulation on the glass.

 

[Dasoss]

The solution I posted in the OP cost about $60 + the cost of the sunshade (there are multiple brands to choose from).

It seems to be working great except for one thing: the insulated wrap adhesive isn't strong and I have found it is detaching from the glass. It does not fall down because the sunshade catches it, but some parts of the wrap are separating from the glass.

I might try some adhesive tape to get it to stay. That will probably work.

If the glass is hot to the touch, it is radiating heat into the cabin. 100%. Covering it with something like what I did to block the radiant heat will definitely reduce the heat coming into the cabin. Film is not an insulator. It works by blocking light, but if the glass is hot, it cannot block that. The answer is to put some insulation on the glass.

I saw advertisement somewhere from a compsny that sells composite replacements for the roof glass. The interior side has insulation and looks like the headliner. Has anyone installed this and would like to comment?

 

[mkhuffman]

I saw advertisement somewhere from a compsny that sells composite replacements for the roof glass. The interior side has insulation and looks like the headliner. Has anyone installed this and would like to comment?

There is a thread from the company selling those roofs on this forum:
https://www.rivianforums.com/forum/...-roof-for-rivian-r1t-by-ev-smart-truck.58477/

They claim insulation properties. IMO it should work as described, but I have not tried it myself. My T is leased so it isn't something I can do.

I recommend following that thread in case someone in this forum decides to try it out.

 

[skyguyscott]

...If the glass is hot to the touch, it is radiating heat into the cabin. 100%. Covering it with something like what I did to block the radiant heat will definitely reduce the heat coming into the cabin. Film is not an insulator. It works by blocking light, but if the glass is hot, it cannot block that. The answer is to put some insulation on the glass.

Well, FWIW, a better answer would be for Rivian just to please, please please install a nice standard moon roof we can tilt open, shade or slide open. Wouldn't that be nice? Do you think Rivian will do it without a lot of kicking and screaming?

 

[mkhuffman]

Well, FWIW, a better answer would be for Rivian just to please, please please install a nice standard moon roof we can tilt open, shade or slide open. Wouldn't that be nice? Do you think Rivian will do it without a lot of kicking and screaming?

100%.

It is super frustrating how all BEVs seem to imitate the Tesla glass roof, like it is the best roof ever. It is useless for the driver except for maybe some extra headroom. I can't see out of the glass roof when driving, nor should I look out it anyway. If I could open it, I could enjoy the air and the sky.

 

[Dasoss]

100%.

It is super frustrating how all BEVs seem to imitate the Tesla glass roof, like it is the best roof ever. It is useless for the driver except for maybe some extra headroom. I can't see out of the glass roof when driving, nor should I look out it anyway. If I could open it, I could enjoy the air and the sky.

Amen

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