Since the energy crisis of 2022, prices have been on the rise - households paid up to 30% more last winter, according to the Federal Network Agency. Particularly in old buildings, a lot of energy is lost through windows, walls, and the cold surface behind radiators; up to 7% of the heat is lost here.
The method: Place aluminum foil behind the radiator to direct radiated heat back into the room. Heating professionals recommend this reflective solution; it works like a heat mirror and costs almost nothing: a roll of aluminum foil usually costs less than 2 euros and is sufficient for several radiators.