Open Fireplaces ~ for domestic purposes these are a means of
providing a heat source by consuming solid fuels with an output
rating of under 50 kW. Room-heaters can be defined in a similar
manner but these are an enclosed appliance as opposed to the
open recessed fireplace.
Components ~ the complete construction required for a domestic
open fireplace installation is composed of the hearth, fireplace
recess, chimney, flue and terminal.
See also BS 5854: Code of practice for flues and flue structures in
buildings.
Open Fireplaces and Flues