Masonry Heating--Not Just a Fireplace

Masonry heating is an ancient technology that is still in use today. A masonry heater is a beautiful architectural feature that uses a quick burning fire to heat up the thermal material of a chimney to radiate heat throughout the house. The radiant heat may last 18 to 24 hours. The thermal mass to absorb the heat is where the beauty comes in: these can be made from brick, stone, tile or stucco.

Kachel tiles are specifically made for this purpose and sometimes this type of heating may be known as a Kachel oven (kachelofen) or tile stove. Other traditional names may be used, like Russian or Finnish fireplace or Swedish stoves.

Because of their design, masonry heaters may also be called contraflow stoves. The principal of the heat transfer is to use a series of channels within the chimney to hold in heat.  A separate small chimney vent is used as a typical chimney is, as a smoke exhaust outlet.

A simplified representation of the contraflow heat channels. A masonry heat system would likely have a maze of contraflow chambers snaking through to hold the heat.

A peek at the construction of a masonry heater may help illustrate how the technology works, and what an impressive home design feature it can be.