Does Window Film Save Energy? Questions & Answers

Energy efficient windows can employ many strategies to reduce heat and energy costs in the home, which will help you save money on energy bills and lower your carbon footprint through greater energy efficiency. One popular technique is window film installation. Window films are a thin layer of thermoplastic that cover the glass and are a cost-effective method many people try.

But does window film save energy in the long term? How much energy does window film save and what other benefits are there to having a film installed? The short answer is yes, for the most part, but there are a few more things to know about window films, such as:

• The performance of energy saving window films varies, which means that a cheaper product can often be much less cost-effective and require replacing more frequently
• The type of window film you should choose depends on your window type, and the film may not perform as well if you do not currently have high-performing energy saving windows
• Many people have window film installed for other reasons, such as to reduce UV rays, glare, or visibility through the glass, and they are often installed on car windows too

Here we will try to answer if it is worth having a film installed and explore other methods to help reduce energy consumption. As suppliers and installers of double and triple-glazed windows in the south coast region of the UK, we can explain the main points. Contact us for a quote today.

How Does Window Film Save Energy? Method & How it Works

The main concept and strategy of a window film is to reflect heat, either from the outside coming in (such as from the sun’s rays during summer) or the inside going out (such as from an interior living space during winter). The reflection method is a very simple method of heat management.

As a result, this method increases the effectiveness of your air conditioning or heating. A film on a window lowers heat loss. Window films work to reduce energy needs and the associated cost.

How Much Energy Does Window Film Save?

The highest-performance window films will provide a significant reduction in heat exchange. These are very thick and will cover large portions of glass, which are often seen in use on large commercial buildings with huge amounts of floor-to-ceiling glazing and high UV ray exposure.

However, it is impossible to say how much energy you might save as many factors are involved. The relevant criteria for film in helping your overall energy reduction include:

• Current energy saving windows: The Window Energy Rating (WER) of your current windows will be crucial to how much your window films save. However, paradoxically, if your windows have a very high WER then the film’s total performance may be lower.
  
• Air leakage in other areas: Films are dependent on reflecting heat, so any area where heat can enter or exit the room will reduce the performance of a film and how much energy it can save. Common sources include doors, floorboards, and uninsulated walls.
  
• Age and deterioration of the film: As films are thin plastic you can encounter issues such as peeling in high heat, scratches, and other damage, which lower the amount of heat that is reflected. Still, you can replace film on small areas of a window quite easily.
  

It is a difficult calculation, but you can measure the impact of a window film by the energy bill reductions they create. A high-performance film on a lower-performance window, such as on a single or double-glazed window as opposed to triple glazing, is likely to be a bit more effective.

What are the Other Benefits of Window Films?

Energy savings are the most common motivator for a person to add window films to glazing in their homes, but several other benefits can make them worth the investment in both domestic and commercial buildings. Some additional benefits of window films may include:

• Lower UV exposure: UV rays are damaging to the carpets, furniture fabrics, wallpaper, and hanging pictures or art inside a room. Window films are effective at reducing UV rays, even if they are not so good at saving energy, so they will reduce damage inside.
  
• Less condensation: There is a much lower chance of misting or fogging in windows with a film, which is owed to better thermal insulation. Condensation can cause humidity, mould, and other problems indoors that can affect your comfort and health.
  
• Heat reduction: While the films reflect heat either way they reduce heat in the glass itself, which is excellent for window films in car windows. Lots of cars use ceramic window films that offer a translucent way of preventing excess heat from accumulating.
  
• Glare reduction: Many people use films to reduce glare in a car, but it is used in very tall buildings with large UV exposure for the same reason. Glare can damage eyes and reduce visibility inside a room, such as in a tall office building, but a film reduces this.
  
• Safety boosts: Commercial, domestic, and vehicular window films can provide a safety boost in the event of damage. Car windows with a film stop the glass from shattering and reduce the chance of a crack occurring in the event of an accidental impact.
  
• Security benefits: Vandalism such as graffiti causes a huge detriment to a property. If you use a window film, you can remove and replace it cost-effectively if this happens. There is an extra level of resistance to intentional scratching or window etching, too.
  
• Higher privacy: Many people install an opaque film with the primary goal of making privacy easier, such as for a bathroom on a low floor or with a street-facing window. If you install a window film you can block the view without blocking much natural light.
  
• Aesthetics: You can easily change the appearance of a window, such as with a floral or pattern design on a front door, while boosting energy efficiency and adding the other benefits we describe above. Many businesses use films for branding and advertising.
  

Even if a window film does not save money by boosting energy efficiency as much as a double or triple-glazed window might, it offers a few other benefits and can deliver increases on less energy-efficient windows that will make them well worth the investment for many people.