Remember all wood fires need air (oxygen) to operate
In order for a wood fire to function correctly, it needs air (oxygen). The flue system is designed to pull air through the fire, but if your house is too airtight, the fire is fighting the natural draught in the flue and you will likely experience problems.
The recommended solution is to open a window to overcome the negative pressure of the house. If all the windows are closed, the oxygen level can be reduced. The wood fire needs oxygen to operate and so do you. It’s easy to doze off in front of the television, but you could be starving yourself of oxygen, so have a window open!