Thursday, March 15, 2018

How to determine a good car window tint film from TSER, UVR and VLT values?

The performance of car window tint film is generally determined by these 3 values:

  • TSER - Total Solar Energy Rejected. This is the overall solar energy filtered by the film. The higher the TSER, the more heat from sun is blocked from entering into your car through its windscreens and windows.
  • UVR - Ultraviolet Rejection. Ultraviolet rays can cause colour fading in upholstery and furnishings. It can also cause skin damage and skin cancer.
  • VLT - Visible Light Transmission. This is determined by the darkness of the film. The darker the film, the lower its VLT will be. Note that JPJ has regulation for the minimum amount of VLT allowed for the tint film, so the VLT need to be equal or above the permitted value to abide to the regulation imposed. As VLT contributes quite a large portion of TSER, it will affect the TSER value pretty significantly.

Traditionally, many tint shops tend to use IRR (infra-red rejection) as an indicator, but the infra-red wavelength spectrum is very long and there is no standard of how much of the spectrum to be used to measure IRR, some products claim to have high IRR by measuring only a short portion of it right after the visible light spectrum, which does not have much meaning for the real heat rejection performance measurement. Therefore, unless the wavelength spectrum of IRR is clearly specified and the measurement is until 2,500 nm or more, otherwise this value can be neglected as TSER can provide a more meaningful value for consideration.

So, how to determine a tint film is good, moderate or poor, based on its TSER, UVR and VLT values?

First we look at VLT value, as it's minimum requirement is regulated in Malaysia. A good VLT value should be as low as possible (so that the TSER value will also be lower) but should not go below the JPJ standard. Otherwise, the enforcement officer may ask you to remove your tints from your windows due to violation of this regulation.

The minimum allowed VLT currently imposed by JPJ is as follow:
  • Front windscreen: 70%
  • Front side windows: 50%
  • Rear side windows: 30%
  • Rear windscreen: 30%

The MS2669:2017 standard has set the requirements for tint film for the following 3 tests:
  • Solar test: VLT, UVT (opposite of UVR) and TSET (opposite of TSER).
  • Weathering test: TSET/TSER value should be stable for a period of 5 years with less than 4% degradation. This is simulated with 1,000 hours shining from solar mercury lamp.
  • Boil test: the tint film should not form bubbles under high temperature.

With reference to this MS2669:2017 standard, we can then determine the range of TSER and UVR which is considered to be good, moderate or marginal only.

  • Good: > 50%
  • Moderate: 39% - 49.99%
  • Marginal: 25% - 38.99%
  • Failed: below 25%

  • Good: > 99.5%
  • Moderate: 98.5% - 99.49%
  • Marginal: 98% - 98.49%
  • Failed: below 98%

Therefore, if you are looking for a good car window tint firm, you can look for those that meet the following realistic requirements:
  • TSER: 56% - 62%
  • UVR: 99.5% - 99.9%
  • Front windscreen VLT: 70% - 75%
  • Front side windows VLT: 50% - 60%
  • Rear side windows VLT: 30% - 50%
  • Rear windscreen VLT: 30% - 50%


Post a Comment

Hint: Click on the "Older Posts" link to continue reading, or click here for a listing of all my past 3 months articles.