Fire constructions

A fire construction comprising a firebox defining a combustion chamber in which a fuel can be burnt, a front opening for access to the combustion chamber for the placement of said fuel configured to be closable by a door, a first air supply means for delivering air into the combustion chamber to support combustion of the fuel therein, and a second air supply means for supplying additional air to further support combustion of particulates and other pollutants rising up within the combustion chamber as by-products of primary combustion, the second air supply means comprising a supply conduit connecting the combustion chamber with an air supply, the supply conduit having a cross section that increases as the supply conduit opens into the combustion chamber to have a generally frustoconical flared region at a location above the fuel in the firebox, wherein the fire construction is a residential fireplace.