Where should I fit a carbon monoxide detector in a room with a log burner?

That's a really important question, because carbon monoxide is a gas that's produced when carbon fuels burn but don't burn properly. It's very poisonous and can kill people while they sleep, so it's great that you're thinking of installing a carbon monoxide detector. What you need to know is whether carbon monoxide is lighter or heavier that the rest of the stuff in the air, which is mostly nitrogen and oxygen. The answer is that carbon monoxide is lighter. What you need to do is put your detector either high up on a wall or on the ceiling. However it should be kept 6 to 12 inches from the corners.