You don’t typically think of candles as effective heat sources, at least not to heat up an entire room. However, the Egloo terracotta heater claims to do just that. By using four small candles and two nested clay domes, it is able to generate enough heat to warm up an office sized room for up to 5 hours at a time. After that, just get a new set of candles. These are super cheap, going for as little as $4 for 100 at IKEA.
The nested dome design, as well as the use of clay ensures that as much of the heat generated by the candles is distributed back to the room at a rate that allows for comfortable enjoyment. It won’t warm your entire home up, but if you’ve got one chilly room you find yourself in often, you might want to consider this innovative alternative. It’s a $60 pledge on their well-funded Indiegogo, and comes in various finishes.