The masonry stove: hot stuff

THE fuel shortages of the early '70s caused many people to seek alternatives to conventional oil heating. The most popular heating system was a method reclaimed from the past: the wood-burning iron stove. In the excitement of rediscovery, some of the problems of our forefathers were overlooked. Masonry heating offers solutions to some problems that are inherent in today's popular wood stoves.

Because the combustion and heat transfer occur in the same chamber in an iron stove, the heat escapes rapidly through the thin metal walls and the fire cannot (and probably should not) reach the 1,100 degrees required for clean combustion, in which the wood is totally consumed. If the wood stove did reach that temperature it would be glowing red hot.

By separating the combustion area (the firebox) from the heat dissipation area (the flues), masonry stoves burn cleanly, leaving no creosote -- a major cause of chimney fires and a recurring problem with iron stoves.

A century ago, pollution was not due as much to industrial production as it was to the extensive use of wood-burning stoves. Big chunks of wood used to feed the fire never burned completely, emitting much smoke, a sure sign of unburned fuel. After the initial lighting of the fire in a masonry stove, there should be no visible smoke coming from the chimney.

Because the iron wall of a wood stove is in direct contact with the air, not only is the stove dangerous to touch, but it ``cooks'' the dust particles that land on it, eventually parching the air in the room and making breathing uncomfortable.

In addition, iron stoves need to be frequently fed; the masonry stove needs firing only twice a day to keep a room comfortably warm and its brick or tile surface about 150 degrees, not hot to the touch.