Fact or Fiction: Will Tin Foil Behind the Radiator Warm Up Your Space?

It’s no secret that older homes are hard to heat. As temperatures drop, old-school radiators can struggle to keep a single room warm, much less an entire house. And if that house has leaky, thin walls, most of the hot air being pumped out of the radiator can just seep right out into the cold outdoors.

As winter approaches, a heating hack is making its way around the internet, promising to increase the temperature in rooms warmed by a radiator. Whether or not it works is another story— let’s take a look.

The Tin Foil Radiator Hack

The hack— as seen on TikTok, in the Irish Sun and many other places online— is straightforward: wrap an old piece of cardboard in tinfoil and place it between your radiator and the wall. The idea is that the tin foil will bounce heat back into the room that otherwise would have escaped out through the poorly insulated wall.

Does the tinfoil radiator hack work?

The science behind the hack is sound, at least in theory. Tin foil is made to reflect heat— it doesn’t conduct or absorb heat. By positioning a large sheet of foil directly behind a radiator, you’re certainly going to reflect at least some heat back into the room.

The question is really whether the tin foil will make a noticeable difference in the room’s temperature. That will depend on the room. This tin foil hack might be able to significantly raise the temperature in a small room, but probably wouldn’t make a substantial difference in a larger, more open room.

Is This Tin Foil Radiator Hack Dangerous?

Anytime a DIYer comes across a home hack online— especially one that involves a potential fire hazard— they should ask one question immediately: is this a safety risk? Placing tin foil and cardboard behind a radiator is not inherently dangerous. After a couple of winters, though, the tin foil will start to oxidize, which could cause trouble.