Does Switchable Glass Block UV Rays?

Yes, switchable glass blocks up to 99% UV rays and this is a major functional benefit for modern buildings. Switchable glass, also known as smart glass or PDLC glass, is engineered to block a high percentage of harmful ultraviolet radiation in both transparent and opaque modes. Their use has rapidly gained traction due to their smart privacy functionality as well as their ability to control sunlight.

Many people ask one of the same questions regarding investment in this product prior to purchasing: "Will a switchable glass prevent ultraviolet (UV) light and help to minimize the amount of solar heat?" As consumers become more aware of indoor comfort and protection, and with increasing energy costs, understanding how this type of glass will perform in regards to UV and solar heat is important. This blog outlines the working method of switchable glass, the UV and heat blocking capabilities of the PDLC layer, real world advantages, and where it works best.

How Much UV Protection Does Switchable Glass Provide?

Switchable glass can block up to 99 percent of UV rays, helping reduce damage caused by prolonged sun exposure while still allowing natural daylight to pass through. It is a smart glass solution manufactured by laminating PDLC Polymer Dispersed Liquid Crystal technology between two layers of glass. The PDLC layer is permanently sealed within the glass during the lamination process, creating a strong, durable, and long lasting glass product.

The laminated glass structure includes specialized interlayers that absorb and reflect ultraviolet radiation. As a result, switchable glass provides up to 99 percent protection from harmful UV rays in both clear and opaque states. This UV protection works continuously and does not depend on whether the glass is switched on or off.

Due to these benefits, switchable glass is widely used in homes, offices, hospitals, retail stores, hotel rooms, and meeting rooms. Along with instant privacy control, switchable glass also offers UV protection and solar management, making it a versatile and high performance solution for modern architectural applications.

Can Switchable Glass Help Block Heat from Sunlight?

Solar Heat Gain Coefficient (SHGC) is used to measure how much heat enters your home or building via glass. The switchable glass will help reduce SHGC by reducing the amount of infrared (IR) that passes through the glass. While the primary function of PDLC films is to provide you with private viewing, they do contain layers that will both reflect and absorb some of the sun's energy, mainly when the glass is in an opaque mode.

When the glass is turned OFF (opaque), it is possible there may be slightly better heat rejection because the scattered light will help block some of the sun's direct rays from penetrating the window. When the switchable glass is turned ON, some of the heat will pass through but at least half of the heat compared to uncoated glass.

How Effective Is Switchable Glass Compared to Other Solar Control Options?

While standard window tints have fixed shading options, switchable glass has a degree of flexibility with its "on/off" or "open/closed" ability as opposed to low-E glass which does an excellent job of thermal performance, however, it needs to be replaced entirely for each different level of thermal performance. While reflective film does a great job at rejecting heat, it also reduces the view-ability of your windows and the aesthetic appeal. This is why switchable glass is an option because it allows you to have complete on demand privacy, reasonable heat rejection, and an attractive appearance, making it an ideal product for areas that need this type of flexibility.

The Energy Efficiency Impact of Switchable Glass

Reduced Cooling Costs

Switchable glass blocks UV rays, reduces solar heat gain and, therefore, lowers indoor temperature levels, especially in hotter climates or when there is a lot of sunlight (such as west facing) coming through windows. The result is a decrease in reliance on air conditioners, which translates into less overall energy usage and lower cooling costs over time.

Smart Privacy + Energy Savings Combined

Unlike curtains or blinds that allow no light into the room but can trap heat, switchable glass allows you to have privacy and still allow daylight to enter. Since this product offers two functions simultaneously, it eliminates the need to purchase other window treatments to block out light and save you money on interior items and energy. It also has a clean look.

When is Switchable Glass Most Useful for UV and Heat Blocking?

Residential Settings

Switchable glass is used to provide privacy and control of sunlight as needed in bathrooms, bedrooms and living areas. It protects interior surfaces from UV degradation and maintains comfortable environments regardless of time of day.

Commercial Buildings

In office spaces, boardrooms, storefronts and clinics, switchable glass provides instant productivity improvement through elimination of glare, heat gain and unwanted privacy intrusion. It allows commercial buildings to be seen with a modern look or image.

Specialized Applications

Museums, hospitals, hotels, etc., can take advantage of UV protection for artwork, medical equipment, and guest areas to prevent deterioration from UV light exposure and improve comfort level for occupants.

Limitations to Consider

Heat Blocking May Vary by Brand

The levels of UV and heat blockage will vary from film to film. The specifications for UV rejection percentage and IR blocking are important to review when selecting your product.

Installation Method Can Affect Performance

How well a switchable glass performs over time is influenced by how it was installed. The quality of the adhesive that holds the film together (edge seal), the connections between the electrical components, and the overall integrity of the installation can affect performance and longevity.

Transparency Levels in ON Mode

In general, even though most PDLC films appear transparent in their clear mode, they tend to have a slight diffusing effect on light. This diffusing effect typically results in less glare but some reduction in visible light transmission and therefore some solar gain.

How to Choose a Switchable Glass With the Best UV/Heat Blocking

Key Specs to Look For

When you are selecting a product for your home, consider the following features of window film products: The percent that will block UVA, the percent that will reject infrared rays, solar heat gain coefficient, and visible light transmission (the amount of natural light coming through). These will give you a better idea of how well each window film option performs.

Questions to Ask Manufacturers or Installers

When discussing the use of window films with your installer, ask them about the performance of these products when they are turned on and off. Also, ask about the length of time they should last (warranty), the cost of the product (power usage) and if it is compatible with any other products that currently exist in your windows.

FAQs

Can switchable glass reduce heat from sunlight?

Yes. While switchable glass is primarily designed for privacy, it also helps reduce heat gain by limiting direct sunlight, which can make interiors cooler and more comfortable.

Does the UV and heat-blocking function work in both transparent and opaque modes?

Typically, the UV protection works in both modes, but heat reduction is more noticeable when the film is opaque because the film scatters sunlight and limits heat transmission.

Will switchable glass completely replace tinted or reflective glass for heat protection?

Not entirely. switchable glass offers moderate heat reduction, but for maximum solar control, it can be combined with tinted or reflective glass. Its main advantage is privacy on demand without compromising natural light.