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
- BEST BANG FOR THE BUCK: Duck Brand Indoor 10-Window Shrink Film Insulator Kit
- BEST FOR LARGE WINDOWS: 3M Indoor 1-Window Insulation Kit
- BEST HEAVY DUTY: Duck MAX Strength Heavy Duty Insulating Film
- BEST LONG LASTING: 3M Outdoor 2-Window Insulation Kit
- ECO-FRIENDLY PICK: Frost King V73/9H Indoor Shrink Window Kit
- EASIEST TO INSTALL: Duck 5 Window Insulation 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 product to keep your home’s warm air where it belongs, check out Duck Brand Indoor 5-Window Shrink Film Insulator Kit. 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. It also comes with 84 feet of Duck double-sided tape.
The film in the kit is 7 millimeters thick and shrinks easily with a hairdryer after a proper installation. As long as you’re careful when you remove the film, you’ll be able to reuse it for several years.
The 3M Indoor Window Insulator Kit has enough film to cover up to five 3-foot by 5-foot windows. The film in this kit is .75 millimeters thick, (.05 thicker than average) so it provides superior insulation. The film comes in one sheet, measuring just over 5 feet wide and 17.5 feet long that you cut to fit.
The 3M Indoor Window Insulator Kit comes with a 10-yard roll of 3M’s Scotch double-sided tape to ensure the film stays up all season long. The insulation material improves the R-value (a measure of thermal resistance) of your windows by 90 percent, which will go a long way to lowering your heating costs.
The Duck Brand Indoor 10-Window Shrink Film Insulator Kit allows you to cover all of your windows at an affordable price while also reducing your energy costs. This kit features .7-millimeter film in two sheets, enough to cover 10 3-foot by 5-foot windows.
This insulation kit also comes with 168 feet of Duck Brand double-sided tape. The sheets are reusable, so you can peel the film off your windows and store them away until they’re needed again.
Massive windows have plenty of potential points for cold air to seep in, and covering them with a standard kit isn’t an option. The 3M Indoor 1-Window Insulation Kit gets the job done with a single sheet of 19.5 by 6 feet plastic film.
With a thickness of .75 millimeters, this 3M insulator is more durable than a standard film, and a good choice for homes with pets and children. This kit also comes with 27 yards of 3M’s Scotch double-sided tape.
Duck MAX Strength Heavy Duty Insulating Film can stand up to homes with children and pets who might tear up thinner window insulation. This kit comes with a sheet of 1.5-milimeter thick film—more than double the thickness of Duck’s standard films. The MAX Strength Kit comes with a sheet measuring 7 feet wide by 10 feet long, enough to cover a patio door, one large window, or two 4-foot by 6-foot windows.
Though the film is thicker than the standard insulating kit, it installs and shrinks the same way, with double-sided tape, a hairdryer, and scissors for trimming. Due to its thickness, you’ll be able to reuse it season after season.
If you prefer to install your insulation film on the outside of your window, you’ll need a long-lasting product that can hold up to the elements. The 3M kit fits the bill, with its high-quality window film.
This 3M kit comes with a sheet of .75-millimeter-thick film that’s more than 5 feet wide and 7 feet long. It comes with just under 14 yards of high-quality, double-sided tape, providing enough material to handle two 3-foot by 5-foot windows. Install this kit with the same process as indoor window kits: cut, tape, shrink, and trim.
Comfort aside, one of the most important reasons to insulate your leaky windows is the impact you can have on the environment. The less you run your heater or air conditioner, the kinder you are to the planet. Frost King’s kit can help reduce your carbon footprint related to heating and cooling costs by up to 35 percent.
This Frost King 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.
The hardest part of installing your window insulation kit is hanging the top edge. Duck Brand’s 5 Window Insulation Kit solves that problem, as it comes out of the package with a pre-taped top edge. Simply run the included Duck double-sided tape down the sides of the window jamb and the sill.
This kit comes with a roll of film that measures over 5 feet wide and 16.5 feet long with a thickness of .7 millimeters. It also includes enough double-sided tape to cover up to five 3-foot by 5-foot windows. Just be careful as you remove the pre-taped edge to ensure that you can reuse the film for an additional season.
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.