Will Window Tinting Make Your House Too Dark? Debunking the Biggest Myth
As spring approaches and summer gets closer, you may be…
If you’ve been researching solar window film, you’ve probably seen impressive percentages attached to different products. One film may advertise high heat rejection, while another highlights infrared rejection or solar energy performance.
So, what percentage of heat can solar window film actually block?
There isn’t one percentage that applies to every window film. Performance depends on the specific film, the type of glass and the complete glazing system. More importantly, understanding what the advertised percentage measures is essential when comparing your options.
Solar energy reaching your windows includes different forms of energy. Window film is designed to manage how much of that solar energy passes through the glass and contributes to indoor heat.
One of the most useful measurements to understand is Total Solar Energy Rejected (TSER).
TSER represents the percentage of total solar energy rejected by the glazing system.
For example, if a particular glass-and-film combination has a TSER rating of 60%, it means that the system rejects 60% of the total incoming solar energy under the conditions used for that rating.
The important point is that the figure applies to the specific glazing system, not automatically to every window where that film might be installed.
You may also see window films advertised with high infrared rejection percentages.
Infrared rejection can be useful information, but it shouldn’t automatically be interpreted as the percentage of total solar heat being rejected. When comparing films, look at the complete performance specifications rather than relying on one impressive number.
Not necessarily.
Visible Light Transmission (VLT) measures how much visible light passes through the glazing. Heat rejection and visible light transmission are separate measurements.
Modern solar films are available with different combinations of solar performance and VLT, allowing property owners to consider heat management alongside how much natural light they want to retain.
Several factors can affect the performance of solar window film.
Different films are manufactured with different technologies, materials and performance specifications. A film designed for strong solar control will not necessarily perform the same as a lighter film intended to retain more visible light.
The type, thickness and construction of your existing glass matter. The same film can perform differently when combined with different glazing.
A large west-facing window receiving intense afternoon sunlight has different requirements from a shaded window receiving limited direct sun.
This is why selecting window film should consider the actual property rather than percentages alone.
Not always.
The goal should be to find the right balance for the space. One property owner may prioritise greater solar control, while another may want to reduce unwanted heat without significantly changing the appearance of the windows.
Choosing purely according to the biggest advertised percentage can overlook other important factors, including visible light, glare, UV protection, glass compatibility and the intended use of the room.
When less solar energy enters through your windows, rooms exposed to direct sunlight can become easier to manage.
This can be particularly valuable for homes, offices and commercial properties with large areas of glass. Solar control can help improve indoor comfort and reduce the demand placed on air-conditioning during hot conditions.
Instead of asking only, “What percentage of heat does this film block?”, ask what the film’s performance ratings mean and whether that particular product is appropriate for your windows.
Gauteng Glass Tint can assess your property and recommend suitable Solar & UV Window Film Solutions based on your glass, sun exposure and what you want the film to achieve.
Want to reduce the impact of solar heat through your windows? Contact Gauteng Glass Tint to discuss the right solar window film solution for your home or business.
For more window film information, advice and completed projects, take a look at Gauteng Glass Tint on Facebook and Instagram.
