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Window insulation kits offer an affordable way to cut the cost of your energy bill and make your home less drafty. For those who can’t afford to replace their windows, these kits are a great alternative.
Most window insulation kits work the same way, by attaching a sheet of heat-shrink plastic or other insulating material to the window panes with double-sided tape or magnetic strips. But since they don’t all perform equally well, we put several of the most popular options to the test in our own homes. Based on those tests, we chose the
<ol><li><strong>BEST OVERALL:</strong>
3M Indoor Window Insulator Kit
<p><strong>Get the 3M indoor window insulation kit at</strong> Amazon.
Runner-Up
Duck Brand Max Strength Window Kit
<p><strong><strong>Get the Duck Brand Max Strength window insulation kit at</strong> Amazon.
Best Bang for the Buck
Duck Brand Shrink Film Window Insulation Kit
<p><strong>Get the Duck Brand shrink film window insulation kit at</strong> Amazon.
Best for Outdoor Use
3M Outdoor Window Insulation Kit
<p><strong>Get the 3M outdoor window insulation kit at</strong> Amazon.
Best Insulation Tape
Yotache Weather Stripping Foam Seal Tape
<p><strong>Get the Yotache window insulation tape at</strong> Amazon.
Best for Multiple Windows
Frost King Window Insulation Shrink Kit
<p><strong>Get the Frost King window insulation kit at</strong> Amazon.
ALSO TESTED
The StangH Portable Thermal Insulated Blackout different foil types, such as plastic, magnetic, and reflective. Features like film thickness, dimensions, reusability, and installation requirements will determine which insulation kit is most suitable for your home.
Several window insulation product types are 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 windows. These kits include double-sided tape and a plastic film that is attached to a window and then shrunk with a blow dryer to create an airtight seal.
- Magnetic insulation kits require DIYers 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.
Dimensions
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 to seal several windows. It’s essential for shoppers to know their windows’ dimensions to determine which kit will work for their home.
Air Lock
Window insulation kits create a trap for air between the window and the film. That trap is called an air lock. Double-sided tape, which holds the film in place on the window pane, will create an air lock. By pressing the film firmly onto the tape, users can create a strong bond that keeps drafts out.
Film Thickness
To create a long-lasting seal, durable film is a must. Durability is often determined by the film’s thickness. Thick film offers more resistance to punctures from kids or pets. It’s also easier to apply correctly, thus establishing a good seal. Thick film does a better job of insulating windows. Standard window film is about 19 micrometers (μm) thick, while heavy-duty film can be as thick as 38 μm.
Number of Windows
Some homes have only one or two truly drafty windows, while others have a slew of them. Choose a kit that has enough film to cover all the drafty windows. Many kits come in multipacks that can cover up to 10 windows. They come with sheets of film that can be cut to size, so every window that needs insulation can be covered.
Reusability
Window insulation kits are meant to be temporary solutions to drafty windows. The good news is that most of these kits are reusable, so buyers won’t have to purchase a new kit every year. Films 19 μm 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.
Installation/Application
The best window insulation kits are effective, affordable, and easy to install. Most kits are installed by placing double-sided tape around the perimeter of the window jamb. Then, window film is applied to the tape. At the bottom of the window, the film is attached to a piece of tape on the sill, making a seal. Finally, the film is heated with a handheld blow dryer to create a transparent, airtight seal free from wrinkles.
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 preventing cold air from entering a 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 airtight 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 it doesn’t block those precious rays of winter sun from shining into a home.
Q. How effective is window insulation film?
Some window insulation kits claim to reduce a home’s energy consumption by up to 35 percent. Users will need to install these products carefully and on every leaky window to maximize their effectiveness.
Meet the Tester
Tom Scalisi is a full-time DIY and construction writer for many of the largest websites in the industry, including BobVila.com, This Old House, Family Handyman, and Forbes as well as his own pest control blog.
