Window insulation kits are an affordable solution to cut the cost of your energy bill and make your home less drafty. When you cannot afford to replace windows, they’re a good option to upgrade ones that are not energy efficient.
Most window insulation kits work the same way: you put a sheet of heat-shrink plastic or other insulating material on the window panes with double-sided tape or magnetic strips to add a layer of insulation. The best window insulation kits are easy to install and provide an effective barrier to drafts. Windows that have been treated with insulation cannot usually be opened, meaning these kits are a seasonal solution to drafty windows.
Read on for shopping considerations when selecting this type of window treatment, and to learn why these are among the best window insulation kits available.
- BEST OVERALL: Duck Brand Indoor 5-Window Shrink Film Insulator Kit
- RUNNER UP: 3M Indoor Window Insulator Kit
- EASIEST TO APPLY: Duck 5 Window Insulation Kit
- BEST FOR OUTDOOR USE: 3M Outdoor 2-Window Insulation Kit
- BEST FOR LARGE WINDOWS: 3M Indoor 1-Window Insulation Kit
- BEST FOR PATIO DOORS: Duck MAX Strength Heavy Duty Insulating Film
- ALSO CONSIDER: Frost King V73/9H Indoor Shrink Window Kit
What to Consider When Choosing the Best Window Insulation Kit
There are a number of factors to consider when shopping for window insulation kits. Window insulation kits are available in plastic, magnetic, and reflective foil types. Features including film thickness, dimensions, reusability, and installation requirements will determine which insulation kit is most suitable for your home.
There are several window insulation product types on the market: plastic film, magnetic barriers, and reflective foil insulation.
- Plastic film insulation kits are the easiest and most cost-effective way to seal off your windows. They use double-sided tape and a plastic film you can shrink with a hairdryer to create an airtight seal.
- Magnetic insulation kits require you to install magnetic strips around the window, then cut the film to match. They can be more challenging to install than plastic film kits, and the magnets often create a less-than-airtight seal.
- Reflective foil insulation kits use shiny metal insulation to keep drafts out. They aren’t transparent, so they block light, and their effectiveness depends on the seal, which can be challenging to get right. These insulation kits tend to be pricier than plastic film and magnetic options.
Windows come in all sizes, so look for kits with enough film to cover your windows. Most kits come with enough plastic sheets and double-sided tape for sealing several windows. It’s essential to know your windows’ dimensions so you’ll know which kit will work for your home.
Window insulation kits work by creating a trap for air between the window and the film. That trap is called an airlock. Double-sided tape, which holds the film in place on the window pane, will let you create an airlock. By pressing the film firmly onto the tape, you’ll create a strong bond that keeps drafts out.
To create a long-lasting seal, you need durable film. Durability is often a factor of the film’s thickness. Thicker film offers more resistance to punctures from kids or pets. It’s also easier to apply correctly and establish a good seal. Thicker film also does a better job of insulating your windows. Standard window film is about .7 millimeters thick, while heavy-duty film can be as thick as 1.5 millimeters.
Number of Windows
Some homes have only one or two truly drafty windows, while others have a slew of them. Pick a kit that has enough film to cover all of your drafty windows Many kits come in multipacks that can cover up to 10 windows. They come with sheets of film you cut to size, so you have the coverage for every window in need of insulation.
Window insulation kits are meant to be temporary solutions to drafty windows. The good news is that most of these kits are reusable, so you won’t have to buy a new kit every year. Films with .7 millimeters or thicker can be peeled off the double-sided tape, folded up and stored when winter is over. The double-sided tape won’t be reusable, but a roll of double-sided tape is cheaper than a houseful of window kits.
The best window insulation kits are effective, affordable, and easy to install. You can install most kits by placing double-sided tape around the perimeter of the window jamb. You’ll then stick the window film to the tape. At the bottom of the window, attach the film to a piece of tape on the sill, making a seal. Heat the film with a handheld blow dryer to create a transparent airtight seal, free from wrinkles.
Our Top Picks
The following recommendations are among the best window insulation kits available in their respective categories.
If you’re looking for a great all-around window film to help keep your home’s warm air where it belongs, check out this option from Duck. This kit comes with a single roll of film that measures 62 inches wide and 210 inches long, allowing you to seal off up to five 3-foot by 5-foot windows. The kit also comes with 84 feet of Duck double-sided tape.
Duck’s window film 7 millimeters thick and shrinks easily with a hairdryer after installation. As long as you’re careful when you remove the film, you’ll be able to reuse it for several years.
From 3M, this kit comes with enough film to cover up two 3-foot by 5-foot windows. At .75 millimeters thick (.05 thicker than average), 3M’s film is relatively thick for enhanced insulation. The film comes in one sheet, measuring just over 5 feet wide and 17.5 feet long that you cut to fit. This kit also comes with a 12-yard roll of double-sided tape to facilitate installation and ensure the film stays up all season long.
Perhaps the most difficult part of installing window film is hanging the top edge. This Duck kit solves that problem, as it comes out of the package with a pre-taped top edge. Once you have set this edge along the top of the window, completing the installation is a simple matter of running the included double-sided tape down the sides of the window jamb and sill. Duck’s kit enables coverage of up to five 3-foot by 5-foot windows.
If you would prefer to install insulating film on the outside of your window, you’ll need a long-lasting product that can hold up to the elements. This outdoor-use window film was created by 3M for that very purpose. Capable of covering up to two 3-foot by 5-foot windows, 3M’s kit comes with a sheet of .75-millimeter-thick film that’s more than 5 feet wide and 7 feet long. It also includes just under 14 yards of high-quality, double-sided tape. Install this kit with the same process as an indoor window film kit: cut, tape, shrink, and trim.
Covering a large feature window with a standard window film kit isn’t an option. To do that, you’ll need a specially designed product like this one from 3M. This kit gets the job done with a single sheet of 19.5 by 6 feet plastic film. Boasting a thickness of .75 millimeters, 3M’s outdoor insulating film is extra durable, and the kit comes with all the double-sided tape necessary for application.
Duck’s heavy-duty insulating film is, at 1.5 millimeters, more than double the thickness of the brand’s standard indoor film. This extra thickness gives the film extra durability, enabling it to withstand wear and tear throughout the season. The film sheet measures 7 feet wide by 10 feet long, giving you more than enough material to cover a patio door (or two 4-foot by 6-foot windows). Despite its special design, this Duck product installs the same way as any other, with scissors, double-sided tape, and a hairdryer.
Comfort aside, one of the most important reasons to insulate drafty windows is to save energy and lower your monthly utility bill. Saving energy also benefits the environment. With Frost King’s window film, you can reduce your carbon footprint related to heating and cooling by up to 35 percent. This kit comes with enough individual sheets of .75-millimeter-thick plastic to cover nine 3-foot by 5-foot windows. It also includes 165 feet of double-sided tape.
FAQs About Your New Window Insulation Kit
Still have questions about choosing the best window insulation kits? Here’s some more information to help you decide.
Q. How does a window insulation kit work?
Window insulation kits create an effective barrier that prevents cold outside air from getting into your home. Heat-shrink film applied to the window pane with double-sided tape creates an air gap that works like a thermal window.
Q. What is the difference between window insulation kits and insulated curtains?
Insulated curtains do a good job of keeping the cold temperatures at bay, but they don’t create air-tight seals to hold back drafts like window insulation kits do. Plus, insulated curtains must be closed to work, so they block natural light. Window insulation film is usually clear, so you don’t block that beneficial winter sunshine from shining into your home.
Q. How effective is window insulation film?
Some window insulation kits claim to reduce your energy consumption by up to 35 percent. While that’s a significant savings, you need to install these kits carefully and on every leaky window to experience their true potential.