Automotive Heat Insulation Film vs. Curtains: How to Choose
With the ongoing intense heat, car interior temperatures can soar. Many car owners opt to install curtains or apply heat insulation film (also known as window tint) to reduce cabin temperature. What are the pros and cons of each option? And how should you choose legal and effective heat insulation film given Hong Kong's strict regulations on window transparency? Kwiksure shares the key things to bear in mind when selecting automotive heat insulation film.
- Automotive Heat Insulation Film vs. Curtains
- Automotive Heat Insulation Film Transparency Requirements
- Construction of Automotive Heat Insulation Film
- How to Choose Automotive Heat Insulation Film
- Cost of Heat Insulation Film
- Maintenance of Heat Insulation Film
- Transport Department Exemption Application Procedure
Automotive Heat Insulation Film vs. Curtains
Both automotive heat insulation films and curtains are popular options for cooling down a vehicle. Here's a comparison of their benefits and drawbacks:
|
Automotive Heat Insulation Film |
Curtains |
|
|
Price |
Higher |
Cheaper |
|
Appearance |
Adheres directly to the glass |
External accessory |
|
Operation |
Moves with window glass |
Manual operation |
|
Heat Insulation |
Depends on the type of film |
High level of opacity |
|
Flexibility |
Irreversible once removed |
Can be removed and installed anytime |
|
Durability |
5 - 10 years |
2 - 3 years |
Automotive Heat Insulation Film Transparency Requirements
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According to Hong Kong’s Road Traffic Ordinance (Cap. 374) and the Transport Department’s regulations, vehicle windows must meet specific transparency requirements. As of April 2023, the latest regulations are as follows:
- All windows (including the windshield) must have a transparency of 70%, unless otherwise specified.
- For vehicles with mirrors on both sides, the rear side windows of private cars, trucks, special-purpose vehicles, and buses must have a transparency of 44%.
- Upper-deck windows and windshields of double-decker buses must also have a transparency of 44%.
Construction of Automotive Heat Insulation Film
What exactly is automotive heat insulation film, and how does it keep the heat out? Automotive heat insulation films (Heat Reduction Window Films) are made from multiple layers of materials, including PET (polyester film), metal reflective coatings, organic dye coatings, scratch-resistant layers, and adhesive coatings. These layers work together to block, reflect, or absorb solar heat, infrared rays, UV rays, and glare, thereby reducing the cabin temperature of the vehicle.
How to Choose Automotive Heat Insulation Film
While the functions of heat insulation films are generally similar, they come with various specifications such as transparency, heat rejection rate, and glare reduction. Besides noting these values, you should also check if the film contains metal layers, as metal layers can block electronic signals, affecting devices like HKeToll, mobile phones, or in-car navigation systems. Always consult with the shop before installation.
|
Heat Reduction Window Film Index |
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|
Lower values indicate higher transparency. Advanced films may not require dark tint for effective insulation; choose films that comply with legal transparency requirements. |
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Higher values mean better UV protection, which helps protect skin and prevent interior plastic parts from aging. |
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Higher values mean better UV protection, which helps protect skin and prevent interior plastic parts from aging. |
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|
Higher values indicate better heat reduction. Infrared rays are a major source of solar heat. |
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|
Higher reflection levels can cause more image reflection on the glass, affecting visibility. |
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|
Lower values indicate better glare reduction, helpful for nighttime driving. |
|
|
Helps reduce glass shattering and works similarly as safety glass. |
|
Cost of Heat Insulation Film
Various brands offer different heat insulation films, and prices vary based on materials and installation methods. Here are the approximate costs for different brands (for a four-door car, in Hong Kong dollars):
|
Brand |
Cost |
|
About $4,000 and up |
|
|
3M Crystalline Glass Heat Insulation Film |
About $5,800 and up |
|
Lamina Glass Heat Insulation Film |
About $3,500 and up |
|
LLUMAR Dragon Film |
About $6,800 and up |
|
About $5,300 and up |
|
|
About $5,680 and up |
|
|
About $2,600 and up (only for side and rear windows) |
Maintenance of Heat Insulation Film
Since heat insulation film doesn’t adhere perfectly to the glass edges, frequent cleaning may let moisture and air into the film, causing bubbles and reducing effectiveness. Clean with water and a towel gently. Also, if planning to steam-clean the interior, inform the service provider about the installed film to avoid damage.
Transport Department Exemption Application Procedure
After applying heat insulation film, you must apply for an exemption from the Transport Department to ensure compliance. Without this exemption, even if the glass meets transparency requirements, it may still be deemed non-compliant during vehicle inspection. The exemption involves the following steps:
- Fill out the "Vehicle Exemption Application Form."
- Submit the form along with a copy of the vehicle registration document to the Transport Department Vehicle Type Approval Unit, 1/F, Comprehensive Vehicle Inspection Building, 18 Sai Tso Wan Road, Tsing Yi, New Territories.
- The Transport Department will send a reply letter in about 2-3 weeks.
- Call to schedule an appointment to bring the vehicle to the inspection center for an inspection (no inspection fee required).
- After passing the inspection, you will receive the exemption. Keep it in the car for proof during checks.
Source: Transport Department
