Energy conservation during the winter is quite the challenge, and if you’re living off the grid you are likely looking for any way to keep the house warm. The trouble is, even the best-insulated home has a leak somewhere. There are ways to close these gaps, such as weather-stripping or shrink wrap, but these can be expensive options or unsuitable for some places. Surprisingly, cardboard can be an economical and convenient insulator, and Eco-Mothering has a list of ways to use cardboard to keep your home warm during the harsh winter months.
Cardboard can be used as a removable draft blocker for windows and doors, or as a vent cover for window air conditioning units. The article recommends corrugated cardboard for the best insulation, although any version can block the exchange of air to some degree. The best part is that cardboard is easy to come by you can just re-purpose some old boxes!