[john_b]

Open fireplaces are mostly used for decoration, not heat. The heat transfer characteristics of a traditional stone open fireplace are rather poor. Most of the heat escapes upward through the chimney, which has to be sized large enough to prevent the smoke problem you mention from becoming noticeable to the inhabitants. Depending on the fire's temperature, much of the heat that does make it into the house is due to radiation, not convection.

For fireplaces-as-heating-systems, rather than fireplaces-as-decoration, closed designs like these are more common:

http://1.bp.blogspot.com/-N6cx8wcRWuU/Uay6KyIgGTI/AAAAAAAAEk...

http://www.jushistone.com/wp-content/uploads/2014/02/firepla...