How Can Buildings Reduce Window Heat? The 5 Best Window Films for Heat Reduction

How Can Buildings Reduce Window Heat? The 5 Best Window Films for Heat Reduction

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How Can Buildings Reduce Window Heat

Window film is one of the most efficient and cost-effective ways to reduce heat in your home or office building. Not only do window films save you time and money, but they also benefit the environment — while increasing  the aesthetic value of your building. 

Professional installation of high-quality heat reduction window films doesn’t have to be complicated. First, the correct 3M window film product needs to be recommended by a certified dealer, like Window Film Depot.  In this post, we’ve compiled the basic science of window heat transfer, the most effective ways to reduce window heat, plus five excellent options for heat reduction window film that cater to residential and commercial properties alike.

Read on learn about:

Understanding Window Heat Transfer

Generally, heat transfer occurs when there is a temperature difference between two objects or spaces, flowing from hot to cold. Heat transfer occurs in three ways:


  • Conduction: The movement of heat through a solid material.
  • Convection: The movement of heat due to the movement of fluid.
  • Radiation: The movement of heat through absorption, reflection, or transmission through electromagnetic waves, mainly in the infrared region.

Naturally, the rules of heat transfer also apply to windows. As interior spaces warm up in winter months, windows transfer heat outside; during hotter summer months, meanwhile, windows absorb heat, warming up air-conditioned spaces and forcing HVAC systems to work harder.

The effects of heat transfer can be extremely detrimental on home temperature costs. According to the Department of Energy, about 30% of a home’s heating energy is lost through windows, while about 76% of sunlight that falls on standard double-pane windows enters to become heat in cooling seasons. To increase heat reduction, property-owners have several options to apply to their windows.

Most Effective Ways to Reduce Window Heat

Most Effective Ways to Reduce Window Heat

There are numerous options for property-owners looking to improve heat reduction properties within home or business. Popular options include weatherstripping, blackout blinds, and even insulating windows with bubble wrap. Two of the most popular opinions, however, are window shades and window film.

Heat Reduction Window Shades vs. Window Film

Heat reduction cellular shades are designed to fold up at the top or bottom of a window, allowing for retractable heat reduction. Traditionally, cellular shades also “shade” a room by obscuring light, offering additional control of natural light within a space.

Window film, meanwhile, is a more permanent solution that is applied onto existing windows. Once installed, window film stays in place throughout the year for consistent, constant window heat reduction. Aesthetically, window film comes in a wide range of opacities, from optically clear to tinted, depending on your property’s needs.

Because window film offers more flexible visibility while maintaining heat reduction, it exceeds window shades in terms of design capability. Temperature control window film can still allow nearly all of the natural light of a traditional window, or provide a tinted environment for properties looking for greater privacy. Adding shades or curtains to windows with film provides additional design flexibility without having to rely solely on them for heat reduction benefits.

How Well Does Temperature Control Window Film Work?

How Well Does Temperature Control Window Film Work

Professionally installed window film is scientifically proven to offer more powerful, consistent heat reduction than other methods. EFILM software models based on the Department of Energy’s standards to model a building before and after window film have shown 3M window film products to reduce up to 78% of the sun’s heat, leading to a net negative carbon impact within six months of installation. 

Beyond heat reduction, installing window film can offer financial incentives for businesses. The recently passed Inflation Reduction Act made it so properties can gain tax credits for reducing emissions of Greenhouse Gasses and Hydrofluorocarbons. Utility companies in some cities even rebate the installation of window film by as much as 50% — making window film a clear financial choice.

Additionally, ConSol Energy and Environmental Solutions, a leading consulting firm for builders, government agencies, utilities, and trade associations, calculated the effects of adding window film to a commercial building. Their study found that temperature control window films installed on single-pane glass showed paybacks in as little as 1.4 years and provided an annual energy savings of 19 kWh/sq ft of glass.

Clearly, exterior window films offer a considerable amount of heat reduction and improved energy efficiency. They are an affordable solution compared to replacing entire windows and can be installed much more quickly with minimal interference in your day-to-day.

Window Heat Reduction Film Installation Options

Window Heat Reduction Film Installation Options

There are quite a few heat reduction window film products available, but they can be broken down into two main categories: those that are installed inside and those installed outside. Both add an additional layer of heat reduction to your existing windows, essentially upgrading them from single-pane windows to double-pane windows, or double to triple.

Interior Installation with Window Heat Reduction Film Kits

This type of window film is applied to the inside of a home or office building. Film heat reduction kits include a large piece of shrink-wrapping plastic that can be cut to size and an adhesive material like tape or magnets which are used to secure the plastic film to the window frame. Once installed, a heating element like a hairdryer is applied to the plastic, which shrinks it to the correct size.

Window film heat reduction kits are one of the cheapest ways to increase heat reduction in your home. However, since they are installed inside, they can be unsightly – which is why many homeowners tend to steer clear of them. Window heat reduction kits need to be installed and removed every year with the change of the seasons. So, if you’re looking for short-term, one-season use, then they might work for you.

Exterior Installation with Retrofit Heat Reducing Window Films

These window films are made up of multiple layers of ultra-thin plastics which are applied with an adhesive to the exterior of existing window glass. Once installed, these films are nearly invisible unless you want to incorporate tinting or mirroring for privacy.

Because they are a permanent solution, these window films have the additional benefit of heat retention in the winter along with retaining cool air in the summer, so you get energy efficiency year-round.

They also provide UV blocking capabilities which will keep your furniture and merchandise from fading and prevent glare for those inside, making for a more comfortable environment overall.

5 Best Window Films for Heat Reduction

Five Best Window Films for Heat Reduction

Convinced about the merits of installing heat reducing window film on your property? We’ve identified 5 excellent options that cater to residential and commercial properties alike.

3M Residential Ceramic Sun Control Window Film

One of the best heat reducing window film options on the market today, the 3M Residential Ceramic Sun Control Window Film will reject up to 80% of harmful heat-producing infrared rays. It also blocks harmful UV rays that can lead to fading, extending the lives of your furnishings. The non-metalized film is manufactured with a scratch-resistant coating that provides clarity and clear views. This ceramic series is also capable of rejecting up to 59% of the heat coming through your windows, which is especially valuable during the warm summer months.

3M Sun Control Night Vision Series Window Film

Ideal for commercial properties, this window film rejects up to 71% of the sun’s heat to reduce glare and eye discomfort. The film offers enhanced views with very low interior reflectivity, especially at night. Its scratch-resistant coating will provide clear views, while the unique nano-technology provides great color stability. As above, you also get the all-important blocking of harmful UV rays that can cause your furniture to fade.

3M Residential Sun Control Prestige Exterior Series

Arguably the best window film for heat reduction available today, this unit does an excellent job at keeping your space nice and cool. The non-metalized film will reject up to 97% of infrared light, providing energy savings and greater comfort. It allows a high transmission of visual light, adding great aesthetics and a stylish exterior. All products in the prestige exterior series range are great for the environment, becoming carbon negative as quickly as 6 months after installation.

3M Residential Sun Control Neutral Series

An excellent heat reducing window film for those on a budget. This product has excellent heat rejection, resulting in significant energy savings and improved comfort. The soft hues give this window film a very sleek and stylish look, while also reducing glare and any eye discomfort. Harmful UV rays will help prevent your furniture from fading quickly and the comprehensive warranty minimizes any risk on your end.

3M Commercial Traditional Sun Control Series

This modern and stylish series is geared towards commercial properties — offering a great way to improve the energy performance of your building without breaking the bank. It blocks up to 99% of harmful UV rays and is excellent at maximizing your privacy. The tinted reflective films are great for your energy performance and can have this product pay for itself within 3 years.

Contact Window Film Depot, Experts in Window Heat Reduction Film

Providing substantial energy savings, benefiting the environment, and boasting seamless design, window heat reduction film is an essential purchase for businesses looking to lower the energy impact of their windows. For smooth installation and expert advice on what temperature control film is best for your property, you should consult the experts.

At Window Film Depot, we tailor our window film solutions to your property’s unique needs — combining incredible communication with hands-on installation from one of our experienced team members. Contact us today to start the process of finding window heat reduction film for your home or business.