It's that time of year when peoples' thoughts turn to staying warm, fireplaces often come up as a method of doing so. There are many kinds, and all have their strengths and weaknesses. In North America, one of the weaknesses is that it is really hard to find units that don't look like something grandma had, so this post will be illustrated primarily with European designs that demonstrate what a good designer can do.
Like this one, the Gyrofocus, designed by Dominique Imbert in 1968, that is in design museums around the world and in 2009, was voted "The world's most beautiful object."
But like all open wood burning fireplaces, it is hopelessly inefficient. An open fireplace can draw as much as 300 cubic feet of heated room air up the chimney every minute. They also produce a lot of particulate pollution, so much so that the City of Montreal has banned them and wants them all eliminated by the end of the decade.
Fireplaces can be improved by bringing in outside air for combustion and having glass doors, but they still are pretty ineffective.