I Tested 12 Ways to Insulate a Window — Only 3 Were Worth It

Window Insulation Test: Key Findings

The video tests 12 low-cost ways to insulate windows. The most effective options trap still air against the glass. Sealing drafts around the window is essential: insulation won’t work well if air can move around it.

The Three Methods That Worked Best

• Heat-shrink window film: Apply the tape to the window frame—not the glass—then stretch the clear film across the opening and shrink it with a hair dryer. The air pocket between the film and glass acts like an extra pane. Install it before a power outage if you may need a hair dryer.
• Large-bubble bubble wrap: Cut it to fit the glass, mist the glass with water, and press the wrap on with the bubbles facing the glass. Don’t pop the bubbles. It’s inexpensive, removable, and lets in daylight, though it blurs the view.
• Rigid foam board: Cut it to fit snugly inside the window opening and add weather-stripping tape around the edges. It provided the strongest insulation in the test, but blocks light and the view.

Practical Setup and Safety Tips

• Seal gaps first with rope caulk or weather stripping, then add insulation.
• During an outage, choose one room to keep warm—preferably one with few windows and an interior wall—and prioritize insulating it.
• Uncover south-facing windows on sunny winter days to collect heat, then cover them again at dusk. North-facing windows that get little sun can stay covered.
• Prepare and label materials in advance, and keep them together in an accessible tote. Bubble wrap and foam can be used without electricity.
• Keep at least one bedroom window easy to open for escape. Don’t wedge rigid foam into an escape window unless it can be removed quickly with one hand.
• Keep foam away from candles, heaters, and other flames. Never use a grill, generator, camp stove, or gas oven indoors for heat. Keep generators and grills outside, and use a battery-powered carbon monoxide alarm near sleeping areas.
• Check insulated windows weekly for condensation, pooled water, frost, or mildew. These may indicate a poor seal and potential moisture damage.
• Treat these as temporary or emergency measures, not as substitutes for proper window repairs or replacement. They slow heat loss but don’t produce heat, and their benefits are generally smaller on modern double-pane windows.

Methods That Performed Poorly

• Foil and emergency Mylar blankets taped directly to glass conducted cold rather than providing useful insulation.
• Towels, cardboard, and sheets offered limited or short-lived benefits.
• Curtains with gaps at the top, sides, or bottom allowed cold air to circulate.
• Rope caulk stopped drafts but did not insulate the glass by itself.

Locations, Products, and Speaker

• Locations mentioned: Walmart, Tractor Supply, hardware stores, old farmhouses, cabins, campers, rentals, and suburban homes.
• Products and materials: Heat-shrink window insulation kits, large-bubble wrap, rigid foam board, rope caulk, weather-stripping tape, thermal curtains, and emergency Mylar blankets.
• Speaker: The host of Ivan’s Survival Journal, sharing personal experience with long power outages and a home window-insulation test.