QUOTE(simchengheng @ Aug 12 2013, 05:34 PM)
i do some readings, quite a lot actually..
found out VLR actually is most contribute to TSER under "Visible Light", is it true?
and the lower value of VLT, it helps for TSER also. and IRR actually is the rest of UV and Visible Light, means even 90%+ IRR, it only means that 90% of the Infra Red Light, which its not visible by human eyes and its only about half of solar energy.
kinda confuse to tinted specs, might be some sort of marketing. so if we are looking for very good heat rejection, gonna go for highest VLR, Lower VLT, Higher IRR? i am feeling like wanna ignore IRR as IRR ratings on different wave show different result, and we cannot confirm in what range of wave for the brand to post out their IRR value.
i am hearing many feedback that pro rating of IRR tint still not very good on heat rejection, while some tint with 85%+- did better than 90%++, 93%, or even 95%. all brand should have a guide line or standards for all those rating, and how the value being carry out.
Actually is very easy, first you need to understand there is 3 ray in natural sun-light. In another word, you are expose to these 3 ray in the same time when you walking under the sun.
a) Visible light (Light which can be seen by human eye)
b) Infra-Red (Invisible)
c) Ultra-Violet (Invisible)
All these 3 rays contribute to Solar Energy. Infra-Red (54%), UV (3%) and Visible Light (43%).

If the film spec IRR90% means 90% of solar energy in Infra-Red Region is reject away, thus it is not represent the whole solar energy. The more accurate film performance is refer to TSER, Total Solar Energy Rejection consist of the solar energy rejection of IR + UV + Visible Light.
Somehow, the TSER value is always low for automobile film. Due to VLT is high, more visible light can pass through, means more energy contain in visible light can pass through. In the other hand, when VLT is low, if the film is darker, the TSER is much higher.
Example :
Raytech Centurion 4mil IRR95%, TSER 62%