Smoke Hoods and Chimneys
This is a cut-away view of a thatched hut with a small three stone fire. The fire needs to be small because there is no chimney; the smoke merely filters through the roof or through a hole. A large fire would create too much draught that could carry sparks up to the roof and start a fire.
The three stone fire has been used for many thousands of years. It combines an efficient combustion area with a stable platform for a cooking pot. If used correctly, with good quality dry wood, it can burn with very little smoke. Poor quality damp wood or too much wood can create more smoke than can quickly 
escape through the roof . The smoke can fill the hut and poison the occupants. These inefficient open fires cause health damage through indoor smoke pollution, burn far more wood than necessary and waste the energy of the people who gather the firewood. This in turn leads to deforestation as people cut down the trees around them for fuel.
The Smoke Bay is a section of a house that is dedicated to collecting smoke. It gets its name from the space between each of the vertical wall and roof truss frames of the house, which are called bays. In this example a roof truss is infilled with material similar to the outside walls. This infilled truss acts as a barrier to the smoke as it rises to the roof, Instead of allowing smoke access to the entire roof as in the small thatched hut example. A hole in the roof allows the smoke to escape and creates a draught that pulls smoke out of the house. The smoke bay can also be used as a smoker. Meat was hung on hooks inside the smoke bay to be preserved by the smoke.

The smoke hood, in this case, is another step between an open indoor fire and fireplace with a chimney. It was used from the late medieval period to the mid 17th century. The smoke hood creates a draught that draws the smoke and sparks from the fire and releases them above the roof. This means less smoke in the house and less chance of fire. A good example of a smoke hood can be seen at Plimoth Plantation in Massachusetts.

The Masonry Fireplace and Chimney