Window Films – What to Look For

Films are another great option for improving the efficiency of your homes windows. This option is most commonly exercised when a homeowner is looking for an upgrade without necessarily replacing the glass or other aspects of the window. Window films are commonly sold as extensions to your existing windows. 

Window Films

Window films are exactly what they sound like, films applied to your homes windows to help reduce the energy lost through your windows and glass. These films block against solar heat gain, and protect against UV exposure. Films are most commonly adopted in southern climates because they can also block the suns heat in the winter. 

They are also particularly useful for homeowners who are looking for an unobstructed view out of their window and don’t have a need to prevent glare or heat gain. They are also an excellent choice if you have a furniture layout that blocks a portion or all of the window. Finally, they are always a recommendation for public buildings such as art galleries or museums who are trying to prevent color from being washed out of their exhibits. 

Window films consist of three layers: 

Window Film Cross Section

Films typically have three layers: an adhesive layer that sits against the glass, a polyester film layer, and a scratch-resistant coating. You may also choose options such as tints, UV blockers, or thicker films that offer security. Low-e films are also emerging as an energy-saving option.

Window films are the first window attachment to be rated by the National Fenestration Rating Council (NFRC), which also created window labeling and ratings for consumers. The NFRC’s Window Film Energy Performance Label looks like this:

NFRC Sample Label

The effectiveness of these reflective films depends on:

·        Size of window glazing area

·        Window orientation

·        Climate

·        Building orientation

·        Whether the window has interior insulation.

Window films have some overall disadvantages:

·        Loss of interior light or visible transmittance

·        Extra care required for cleaning

·        Reflections

What to look for in a Window Warranty

Just like every window is not created equally because of their NFRC rating, not all window warranties are the same either. 

Warranties on products are meant to both inspire confidence in the consumers perception of a product and to protect a consumer from any repairs or replacement costs associated with a product malfunction or failure during any warranty period.  

Warranties on new or replacement windows are critical in protecting your wallet from costly damages. Furthermore, warranties on the glass may be available and offered separately from your window based on the manufacturer. Below are some tips to help differentiate different warranties associated with windows. 

Questions to ask about Window Warranties when shopping for new windows

  • Do you offer a warranty on all your windows?
  • How long is the warranty valid for?
  • Does the warranty cover all parts? Only the Window Frame? Only the Window Glass?
  • Is the warranty limited or full?
  • Does the warranty cover labor?
  • How easy is it to register for the warranty?
  • How soon can I expect my window to be fixed or replaced while under warranty?
  • Is the warranty transferable (passed along to subsequent homeowners)?

Window Warranty Basics

Window warranties are NOT mandatory, which could leave you in a hot water if your new windows start giving you problems. We recommend asking your window installer the following questions to ensure your window’s warranty is right for your situation.

Do you offer a warranty on your windows? Since warranties are not mandatory, some companies may not offer or include a warranty for your windows. If your contractor does not offer any warranties with the installation, consider purchasing a warranty directly from the manufacturer. If neither option is available this should be an immediate red flag and should consider finding a different window contractor.

How long is the warranty valid for? The scope of warranties often differ by product, brand, or manufacturer. Some warranties may be a “lifetime” warranty, meaning they are valid forever. Others may only be valid for one, five, or 10 years, while others may last as long as 20! Always ask which parts and services are included with the warranty!

Does the warranty cover all parts? A window may seem simple, but depending on the function, it may have moving parts like in double hung or casement windows. A manufacturer’s warranty may or may not cover the glass, hardware (e.g. its lock, hinges), window screen, etc. Be sure to ask what parts are covered in your window’s warranty. Ideally, all parts are protected under your warranty and the labor associated with fixing any defective parts.

Does the warranty cover labor? Similar to covering the various parts of a window, a warranty may or may not cover its installation. Although you can rely on most companies to properly install a window (especially if they are a window and door company), your windows may be installed incorrectly and result in insecure seals or a malfunction. Common sealant failures are explained in depth by the largest sealant manufacturer if you are installing windows on your own.

Is the warranty a limited warranty or full warranty? Not every window warranties are the same. If your window comes with a full warranty then all parts should be replaced by the manufacturer or contractor in a reasonable amount of time at your convenience. A limited warranty is more strictly regulated and may only apply to certain parts or appeal to specific defects. Limited warranties offer less coverage than a full warranty and are only as specific in their coverage as the manufacturer or retailer wants.

Energy Savings Guide to Replacing Your Home Windows

This article will teach you how to take advantage of energy rating on your homes windows by understanding and utilizing the information regarding your homes zone rating, the window warranty, and the window efficiency claims. 

The most information regarding the effects of energy loss, heat loss, and solar reflectance for your windows is located on the NFRC label, like the image below. The NFRC (National Fenestration Rating Council) label illustrates the test results from an independent testing laboratory which will enable you to compare and understand the performance of your windows and a potential window replacement. While, independent testing results are not required by law from window manufacturers and installers, the majority of large residential and commercial window suppliers subject their products to this level of scrutiny.

 Therefore, the NFRC label is both your assurance that your windows meet specific energy regulations and a comparison tool to identify the replacement window for your need. The test and rating scale for NFRC labels is displayed below. 

NFRC Label Example

NFRC Categories

Energy Star: The shaded potions of the map show where a window meets Energy Star criteria. This unit passes muster nationwide.

Visible Transmittance (VT): Specifies how much light passes through; 0 is opaque, 1 is transparent. Glass with a VT of .60 or more looks clear. A VT below 0.40 gives things a grayish cast.

U-Factor: Measures how effectively a window stops heat flow. The smaller the number, the better the performance.

Solar Heat Gain Coefficient (SHGC): Indicates the ability of the glass to block the sun’s heat. The lower the number, the less heat gets in. In the northern zone (see map below), an SHGC of 0.32 or more can offset less-than-ideal U-factors up to 0.30.

Know Your Energy Rating Zone

In many instances, two windows that look exactly the same may not perform exactly the same. In short, not all windows are created equally. The differences between two identical windows can be seen more visibly by differences in the energy efficiency ratings. The Federal Law dictates specific efficiency ratings based on your geographic location. Below is a map which dictates the minimum level of efficiency based on your location in the United States. 

Energy Star Regions based on Efficiency

Perhaps the most important take away from this article should be that the minimum energy rating for your windows IS NOT the recommended rating. 

Colder climates such as the Midwest (Wisconsin, Minnesota, Illinois) it is recommended to have at least triple pane glass windows with a high solar reflectance rating (U factor) to offset the costs associated with cold winters and hot summers. 

Think of your windows as an investment, and with any investment consider the window and glass package that best fits your homes needs.

Energy Saving Tips

Try these tips for enhancing the performance of your window by improving the glass and insulation.

Low-e coatings: These transparent, micron-thin layers of metal reflect heat either toward the interior (in cold climates) or toward the exterior (in warm ones), depending on the glass surface they’re fused to. The can reduce heat loss (or gain) by as much as 35 percent, per information from the U.S. Department of Energy.

Inert gases: Air trapped between panes insulates fairly well, but if a gas such as Argon is used instead, performance improves by 16 percent. Xenon and krypton insulate even better than argon. These heavier gasses will improve the R-Value of your windows by at least 0.5 points.

Warm-edge spacers: Standard aluminum spaces conduct lots of heat through the edges of double-pane glass. Nonmetallic, warm-edge spacers bring those loses down by 10 percent, per Cardinal Glass, and make it more difficult for condensation to corm on inside panes.

For more information on why to replace your windows read more here.