Convected air from the room to be heated enters two first air spaces (10) through two front inlets (12) and circulates through passageways (13) between inner and outer casings forming the fireplace and re-enters the room through front air outlets (14). Cold fresh air from outside the room enters a second air space (14), between the two first air spaces (10), and can be fed into the room through a control vent (16) for promoting combustion within the fire and/or can be fed into the first air spaces (10) so as to supplement the convected air flowing through the passageways (11).