Window tint is almost a must here in OK due to the sun and heat. It makes a huge difference in the cabin temps.
Ironically, it seems like some of the cars with the darkest and theoretically illegal tint is on law enforcement vehicles. OK has statutes on tint but I don’t think that it’s something that is heavily enforced.
If you lived here in the desert southwest, you’d know that window tint is the most popular aftermarket accessory, and for good reason. Not only does tint keep your car cooler and more comfortable, but it prolongs the life and appearance of your car’s interior.
Same for Florida law enforcement. Limo tint that they’d pull you over for having!
Yeah, I shopped around and never did it on the Neon. There’s the old game… $99, for 2 windows. But the better stuff is twice as much for “materials” and more if you want all windows. Then the salesman slips, quotes $300 for 4 windows. “Did I say $300? Ok, I guess I can do it for $300”. You know you are getting screwed, but get to hang and listen to shop talk.
The installer rolls in (always a young guy) but really good at his specialty and it’s a social occasion while everyone watches the “pro”… sort of like when the Snap-on man rolls in. His apprentice mostly stood around. Talk turned to becoming independent and he related about his previous apprentice. His goal was to get good at the job, branch out on his own, and move back to CA. The tech said, “He’ll starve. They charge $100 for a complete car. One mistake and you’ve lost your profit for the job.”
I assumed he meant for “street vendors”… sort of like heading to Tijuana to have your car upholstered. This is in Eugene.
A legitimate tinting shop will normally use tint that complies with state law. My car has a compliance sticker on the door jam.
However I have a friend that is a LEO, she had limousine dark tint on on her windows. LEOs rarely ticket other LEOs.
Limo tint actually causes the vehicle interior to be hotter. Black absorbs more of the suns rays, heats up and black also radiates heat more than any other color so it radiates heat into the interior.
Mirror tint will keep the interior the coolest, but the reflections can blind other drivers so it is not generally allowed any more.
All car windows are tinted from the factory with a UV tint that is about 90% transmissive to visible light. It blocks well over 90% of the suns UV rays and does more to keep your interior cool than any other tint except mirror tint.
The 20% (dark) tints and the 38-39% (35% total with the factory UV tint) will make the car seem cooler to the occupants because it blocks a lot of the suns IR rays that cuses your skin to feel hot. It’s like sitting in the shade compared to sitting out in the sun. But these do little to actually bring down the temperature inside the vehicle.
For the record, windows are tinted with the ceramic tint to a total of 35%, but I also have a 5% tint strip at the top of my windshield. This makes driving into the sun during sunset or sunrise a lot safer and more comfortable. These tint strips are legal down the the as_ mark on the windshield or 6" if no mark, mines about 7" but who’s measuring.
Then how do explain a drop in temp for an occupant-less car sitting in the sun? No human perception issues there. I tinted the rear and rear-quarter windows of my red Mustang after bringing it to Florida. It made a significant difference in interior temps after tinting that big, fastback, rear window.
A bigger difference is leaving the windows down 1/2 inch. Adding vent shades prevents the rain from getting in so you can do that. It is the only way my black Avalanche doesn’t set the interior on fire sitting in the sun.
I’m not going to explain anything. I have no idea what tint you used or the exact circumstances under which you did this test. But Google “emissivity” and you will understand my statement.
From the manufacturers own website. Their claims back up my anecdotal experience.
https://www.3m.com/3M/en_US/automotive-window-solutions-us/solutions/temperature-control/
I’ve done that too, but I don’t crack the windows when I’m parking it long term because I’m worried about a bee building a nest in there.
Exactly. All tints block UV, and the darker the shade, the more that’s blocked. Ceramic coated blocks a higher percentage than standard film. The film I used blocks 92% of the UV that gets past the factory tint.
UV passes thru untreated glass more easily than heat. The UV passes in, heats surfaces it strikes, then is mostly trapped inside. Darker windows will get hotter, but more of that heat is radiated back outside, rather than heating the interior. That’s why most home windows have UV coatings… light comes in, heat stays out.
Visible light is a different frequency. While 92+ of UV was blocked, 35% of visible comes in. On a bright day, that’s about equivalent to wearing polarized glasses… plenty of light to see by, but less solar gain.
They are comparing to untinted windows. Almost all, if not all new vehicles have UV tinting in all their windows, including the windshield.
They are also only comparing the transmission for the suns rays. They are not accounting for the fact that a dark surface will absorb more heat than a light surface and will then in turn radiate more of that heat compared to a lighter surface. That is known as the law of reciprocity.
They can help if you have a dark colored interior as the less of the suns rays that hit the interior surfaces, the less they heat up so the less they radiate. That doesn’t help as much if you have a light colored interior. But if you touch a tinted window and compare it to touching an untinted window in the same place, the tinted window will have a higher surface temperature.
Yes, ideally the film would be applied outside the glass, or you’d use double/triple pane windows. Mfgrs tint as a compromise to reduce heat gain. Tints are a compromise to having glass replaced or removed and chemically tinted (expensive). It is applied inside for durability.
I expect light management systems in the next decade.The technology has been around for a while to pass a current thru a film to change light transmission. (I think some sunroofs use this?) In these, you can have 100% transmission at night, near zero when parked, somewhere in between as needed. www.continental-automotive.com is one company offering the system.