Did you know that windows account for a quarter to almost a third of heating energy losses in buildings? That’s because untreated glass panes have a low heat transfer resistance rate. As a result, a considerable chunk of heating and cooling energy gets lost through windows.
What’s more, the clarity of windows allows the sun’s heat, light, and ultraviolet rays to enter. For example, solar thermal energy heats the glass as sunlight streams through it. Excessive sunlight and UV radiation can also penetrate bare windows.
You can avoid these by installing window films with the right tint percentage. Most window films also provide up to 99% UV protection while also rejecting up to 80% of solar heat.
How exactly do you choose the best tint percentage for your business, though? What does “percentage” mean when it comes to window tinting, anyway?
We’ll answer all these questions in this comprehensive guide, so be sure to read on!
A Primer on Tint Percentage and Visible Light Transmission
First things first: there’s no cap when it comes to the legal tint percentage for buildings. Tinting laws only apply to vehicles in the United States. What these films have in common is the use of the term “Visible Light Transmission” (VLT).
Visible Light Transmission is the term used to represent different tint percentages. VLT refers to the amount of light that materials, be it glass panes or window films, allow to pass through.
The higher the VLT rate is, the more amount of light the material transmits. A higher VLT percentage also means that the tint itself is lighter.
Let’s use a window film VLT percentage of 80% as an example. In this case, the tinting product transmits 80% of light. In terms of “shade,” an 80% tint percentage is also visibly lighter than, say, a film with only 50% VLT.
By contrast, a window film with a 20% VLT only lets 20% of light in as it blocks 80% of sunlight. This low light transmission rate also makes the tint darker than other films with a higher VLT.
Factors to Consider When Choosing Tint Percentages
When deciding on commercial window film VLT percentages, consider the product’s installation location. After all, not all your windows may require heavy tinting, such as those that don’t face the sun. Sunlight won’t enter north-facing windows, so you may not really need very dark films for these.
You should also make a list of what you want from the films: reduce sun glare or enhance privacy? Perhaps your goal is to enhance your office building’s weather control elements. Another purpose you may have in mind is to limit UV transmission without making a room too dark.
Don’t forget to factor in specific health or medical considerations. For example, you may have employees with lupus, a disease affecting an estimated 1.5 million people in the US. Health experts say that sunlight exposure may trigger the disease’s signs and symptoms.
When to Go With a Darker Tint
Window films with a 20% or lower tint percentage can give you the privacy your office needs. These are excellent for ground-floor offices with lots of windows facing the street. The dark shading ensures that people can’t peer into the room from outside.
If you want the highest level of privacy but you also want some natural light to come in, then a 20% VLT is a good choice. In this case, you can still expect up to 20% of the sunlight to stream through the film.
The reflective window film type is one of the best options for enhancing privacy. These films block visibility from the outside. However, people from inside the building can still see what’s outside.
It’s also best to go with darker tints is if you have employees with light-related conditions. Aside from lupus, there’s also scleroderma, affecting an estimated 300,000 people in the US. It’s an autoimmune disorder that can cause photosensitivity.
Speaking of light sensitivity, many polymers, including electronics, are also UV-sensitive. In fact, UV radiation degrades these materials and causes their early failure.
What’s more, the UV degradation process leads to the production of free radicals. Over time, the deteriorated materials can emit particulate matter into the air.
For these reasons, you’d want to go with heavy tints for rooms full of electronic devices. At the office, this can be your IT (information technology) department’s hub. It can also be the room housing your network server equipment.
When to Choose a Lighter Tint
A 50% tint percentage may be better for businesses with indoor displays. These include stores on the ground floor that have window displays.
At 50%, the tint will allow enough light to permeate so that customers can see products on display. At the same time, the film will block half of the sunlight to keep things inside from being too bright.
You may also want to go with a 50% or higher VLT for windows that have exceptional views. Maybe you have windows that face a tree-filled urban green space or park. You don’t want to block the views with too dark films, so a tint with 50% is a good starting point.
There are also specialty window films that provide virtually invisible solar control benefits. Their unobtrusive, see-through design makes them less noticeable on your windows. However, they still provide maximum UV and adequate solar heat protection.
A 50% or higher tint percentage is also ideal for northeast- or northwest- facing windows. That’s because they don’t get as much sunlight as east-, west-, our south-facing windows. They do get some light in the early morning or late afternoon, though, which is why you still want some shade on them.
Tint Your Windows With the Right VLT Percentage
As you can see, the right tint percentage depends on many factors, such as window location. What exactly you want from the window films will also influence how dark or light you want the tint to be. As a general rule, though, darker is better for privacy, while a 50% VLT is good for adequate sun control.
If you’re still unsure, don’t worry, as window film experts can help you decide on the best tint percentage.
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