[jetsetgo08]

Noob question. Weren't the branded aftermarket sunfilms UV protective? And what is the VLT level on the UV Cut glass?

If the aftermarket sunfilms are UV protective as well, then it is logically sensible to lift the ban on sunfilms with 70% VLT.

[Kosfactor]

Originally Posted by --gKrish--

I do not know about the condition in Bangalore but here in Kerala, during March of 2019 alone there were more than 290 admits because of sunburn/stroke (4 have lost their lives already) .

OT : I've been trying to figure out the correlation between the rape cases in our country and an inanimate object like sun control film from the day this ban was imposed. Am I missing some point?

I do not want to question the wisdom of the court in this case.

Heatstroke and sunburn are different. Heatstroke happens when its hot and humidity is hight to prevent your body from regulating its core temperature. Sunfilm wont help here, AC will.

The solar radiation at ground level is mostly visible light, yes there is UV too most of that UV can be taken care of by most of the new car's OEM glass. Even the nano had a greenish tinted glass in the top spec.

[drmohitg]

Interesting query posted on whatsapp group by a friend: What if your non tinted car goes in for a windscreen replacement now? Will they fix the tinted glass and return it?

Regarding the SC ruling, I could see a bit of confusion. So here are the facts:
1. The rule was imposed after the infamous Nirbhaya Case since the Police said that the bus with tinted glasses aided in the crime as no one could see inside the bus. A valid point.

2. The SC admitted indirectly that they don't have the manpower or motivation to check the sale of dark sunfilms, beyond the permissible limits. Also in that environment there was an urgent expectation from our government to come out with some steps to check such crimes. And off late the SC and NGT have been having a gala time in delivering nonsensical illogical judgements in cases where they can do little otherwise: Sunfilm ban was the start of this trend and now the diesel/petrol car ban in Delhi NCR.

3. Sunfilms were never as such allowed. The rule just stated that the visibility of front and rear glasses needs to be 70% and side glasses needs to be 50% at the least. The SC just clarified that while the allowed visibility still stays 70/50, but one cannot add an aftermarket sun film, regardless of the visibility it offers. In short it banned sun films. Tinted OEM glasses were allowed.

[jetsetgo08]

As per Garware suncontrol film website, all the sunfilms are rated for <1% UV Transmittance, but with various levels of Visible Light,IR, Solar Energy Transmittance that control the cabin temperature. So how are the UV Cut glasses beneficial over a sun control film?

Off-lately, I have seen a lot of vehicles with 50-70% VLT green/natural shade sunfilms. But, it seems the law enforcement officials are not too strict over the ambiguity in this rule or do not have the expertise to distinguish sunfilm over a UV Cut glass.

[greenhorn]

At this point, lifting the ban on sunfilm is pointless because you still have an umbrella ruling in place which says no modifications are allowed, and this still falls under that bucket. Cops will continue to harass in the name of that ruling

[Divyendu Sharma]

Originally Posted by greenhorn

At this point, lifting the ban on sunfilm is pointless because you still have an umbrella ruling in place which says no modifications are allowed, and this still falls under that bucket. Cops will continue to harass in the name of that ruling

I have done so much research on this topic.The rule states that VLT of 50 on side glasses and VLT 70 on windshields is allowed only if it is factory fitted at the time of delivery.

The reason sun film ban still holds because it would be very difficult to monitor if everyone is abiding by the VLT numbers .

Technically it is still illegal to change car glasses after delivery.

[greenhorn]

Somewhat related - My indica DLG came with a partially tinted front windshield. When i replaced it, i was told that the tinted ones were no longer available, and had to settle for an untinted one. Not sure where that falls legally. I am driving around in a car that was modified from factory spec, but to match to factory spec, i need to add tints.....which are illegal. Whattodo?

[niteshbids]

Originally Posted by ashlil

Brushing up on my 12th standard physics:

So, it can be seen that most of the energy coming from the sun lies in the UV range. If one can effectively block the UV range, one can reduce the heat by a great deal.

While the UV does have more energy, it's not true about the heat. The heat is carried predominantly by the infra-red end of the spectrum. For effective heat control, it is the IR that needs to be controlled. UV control is required due to its harmful effects on the human skin. Ironically, the same UV is also required by our skin for making Vitamin D.

Originally Posted by Akshay1234

What favour did the supreme court do us? Any of the smaller towns and cities still have people running jet black tints.

BTW a 70% visibility film isn't rejecting a large amount of visible light. Yet how is it that the film still manages to cut out a large amount of heat and reduce the burning sensation felt on bare skin?

Blocking visible light is not necessary for blocking heat. Although it's difficult to achieve one without affecting the other parts of the solar spectrum.

Originally Posted by Kosfactor

The sunlight that hits all of us do not have much of this harmful UV on one end of the spectrum and the Infrared on the other end of the spectrum like their marketing department make you believe. Else all the poor chaps who are out in the sun will perish.

The Sunlight has enough of both of these. The UV is enough to be an essential factor for Vitamin D and to be one of the prime sources for skin cancer. The brown skin tone that we have in India and the black skin tone in African countries is the human body's defence against the same.

The IR is also enough to cause all the heat that we feel in the sun.

Originally Posted by hiren.mistry

But why the green shade? Wouldn't brown be a universal color when it comes to matching with the car's paintjob?

The choice of green IMHO is not for aesthetic factors. As green lies bang in the middle of the visible spectrum VIBGYOR, it would have been easier for them to work with this color in order to address desired results at both ends of the spectrum.

A little bit OT: The reason cars get so hot inside standing under the sun is that infra red rays have an interesting interaction property with glass. Once an IR ray passes through glass, the wavelength of the ray is increased. This ray having the increased wavelength is unable to cross glass surfaces again. Thus they tend to accumulate inside causing the car to heat up. The same principle/property is utilised in solar cookers and solar water heaters. Solar electricity on the other hand depends on the UV

[tsk1979]

I am confused here. 50% or greater transmission tinted glass has existed for long time all over the world. What really is the news here?

[avira_tk]

Originally Posted by tsk1979

I am confused here. 50% or greater transmission tinted glass has existed for long time all over the world. What really is the news here?

The news is that we are getting it in India for the first time, a necessity because of the sun film ban. I don't think any oem offered this earlier.

[tsk1979]

Originally Posted by avira_tk

The news is that we are getting it in India for the first time, a necessity because of the sun film ban. I don't think any oem offered this earlier.

How is the Sun film ban related to tinted windows. Any manufacturer could have gone for greater than 50% transmission glass at any time. The courts only banned after market sun films over and above the factory transmission.
Many vehicles came with lightly tinted side windows

[Kosfactor]

Originally Posted by niteshbids

A little bit OT: The reason cars get so hot inside standing under the sun is that infra red rays have an interesting interaction property with glass. Once an IR ray passes through glass, the wavelength of the ray is increased. This ray having the increased wavelength is unable to cross glass surfaces again. Thus they tend to accumulate inside causing the car to heat up. The same principle/property is utilised in solar cookers and solar water heaters. Solar electricity on the other hand depends on the UV

Back in high school we made a solar evaporative water purifier which has no moving parts, it worked on glasshouse principle. Visible light (mostly) from the sun enters the cabinet through glass that does not allow most of infrared inside and gets absorbed by the black interior which absorbs visible light and radiates infrared (heat)which gets blocked by the same glass the other way around and it makes the inside of this cabinet hot aiding evaporation of water...yes so glass by default blocks a lot of infrared spectrum radiation, therefore your car interiors get heated up because the heat cannot escape.

Originally Posted by tsk1979

How is the Sun film ban related to tinted windows. Any manufacturer could have gone for greater than 50% transmission glass at any time. The courts only banned after market sun films over and above the factory transmission.
Many vehicles came with lightly tinted side windows

Precisely, most of the new cars have slight tinted side windows.

This is an interesting discussion - My point to be clear being this.

Visible light can cause heating of most things and those objects radiate heat in the form of infrared. So the glass needs to be able to radiate this heat from the inside to the exterior while not letting infrared to go through it from the outside to be effective.

or simply block more visible light with a rollup privacy screen like some of the new cars.

[ViruKM]

Is that why some people leave one window partially closed?

[niteshbids]

Originally Posted by ViruKM

Is that why some people leave one window partially closed?

Yes. This lets part of the heat out.

[rahulskumar]

Jazz has a huge windshield and bring in all the heat from outside. Did anyone opt for this glass and how much did it cost ?