Heat reduction ratings on 35% Tints. What's yours?

[Coaster]

When talking glass, there are 2 main properties. SOLAR HEAT GAIN and CONDUCTANCE.

SOLAR HEAT GAIN (SHG), whereby direct sunlight energy enters the vehicle and is converted to heat energy. There is a co-efficient (SHGC) that is expressed as a number between 0 and 1 to rate glass and films.

There is also CONDUCTANCE; the rate of non-solar heat transfer across the glass. You can think of it like osmosis, where the temperature on either side of the glass tries to even themselves out. The more the glass can resist this transfer the better. It is known as the U-Value and ranges from 2.0 to 10.0.

Now in terms of what that means to window tinting, it is the SHG that they are commonly referring to. It is generally very difficult and expensive to reduce conductance, most tints/films don't do much to reduce conductance.

Ask for the SHGC and U-Values for each of the tints/films to make an assessment between the makes/types of tint. Since the U-Value is very hard to reduce, I would look mainly at the SHGC and the UVA/UVB reduction.

[Ralfi]

Well, I need to find a balance or glare/heat reduction, while still allowing some light in - & i'm weary of making things too dark (whilst being fine for day time driving) but not being able to see things properly at night.

I won't have a sunroof, so i'm counting on the front windscreen to let natural light in, & even though it'll also let the heat in, i'll counter that with my killer airflow techniques & the tint on the sides/rear.

edit...
Thanks, Coaster. So the lower the SHGC the better correct? I wonder if the SHGC value would be stated anywhere on the receipt of people who have had tints done? Can anyone verify this?

[Coaster]

That's correct, the lower the better.
As far as I know, the value is linear.