Types of heat insulation film for car windows, and the difference between heat film and tinting
Why the car heats up, what heat film actually does, what the types are, and why darkness is not insulation. The guide to read before you choose a heat insulation film.
A car parked in the August sun: you can't hold the steering wheel, and the air conditioning needs time to catch up. The fix everyone suggests is "get heat film fitted". But heat insulation film for car windows is a broad label, and under it there are films that really cool and films that only darken.
This is a guide to the types of heat insulation film for car windows, and what to ask about before you pay.
Why does the car heat up inside?
Because the glass lets the sun's rays in and doesn't let the heat out. And the sun's rays come in three kinds:
- Infrared (IR): it can't be seen, and it is about half of the sun's energy. This is what you feel as heat on your skin.
- Visible light: what we see by, and it carries a large part of the energy too.
- Ultraviolet (UV): a small part of the energy, but it is what fades the upholstery and the dashboard over the years.
Heat film is fitted on the glass to block part of these rays before they get in.
What is the difference between heat insulation and tinting?
Tinting cuts light, and heat insulation cuts heat. They are not the same thing.
The common mistake is to think the dark film is the one that insulates. How dark a film is only means that less light gets through. Infrared has nothing to do with the colour of the film: a clear film can block more of it than a cheap dark film.
That is why the clear heat insulation film we fit doesn't darken the glass: its job is heat, and it cools the car without changing the colour of the glass.
What are the types of heat insulation film for car windows?
There are four main types on the market:
- Dyed: the cheapest. It darkens the glass, it insulates little against heat, and its colour fades over time.
- Metallic: it has a metal layer that reflects heat. It insulates well, but it can affect mobile and GPS signal.
- Carbon: no metal, so no signal problem, and its colour is more stable than dyed film.
- Ceramic or nano ceramic: it focuses on blocking infrared without metal, and it can be clear. This is usually the most expensive type.
The name "nano ceramic" is also used for a liquid coating that has nothing to do with heat insulation. The difference is in Nano ceramic for glass or heat insulation film?.
Which figures should I ask about?
- Visible light transmission (VLT): the higher the figure, the lighter the film.
- Infrared rejection (IR): the big number in the adverts.
- Total heat rejection (TSER): the closest to what you feel, and usually lower than the IR figure.
- Brand: the name of the manufacturer.
And compare like with like. "98% infrared" and "60% total heat" are two different measures. The 98% we quote for our film is an infrared figure: by this site's calculation that is about 57% of the sun's total heat.
Heat insulation film at EGY X
- The film: 3M, clear, and it doesn't darken the glass.
- Performance: it blocks up to 98% of infrared rays.
- Price: EGP 3,500.
- After fitting: don't open the windows for 3 days, so the film can set.
Heat insulation film is included in the paint protection film packages, and it is also fitted on its own as a service. The details are on the heat insulation film page.
We also have a separate service called Window Tint with Heat Insulation: 3M, 30% tint and 70% heat insulation, fitted on the four doors and the rear glass, priced at EGP 3,500. The difference, simply: the clear heat film cools the car without changing the colour of the glass; window tint with heat insulation darkens and insulates.
