Hearth ventilators for domestic fireplaces

Claim 1

An improved system for providing a supply of air to a fireplace for supporting combustion in the firebox thereof and for cooling the walls of the fireplace from a source outside the space wherein the fireplace is installed said fireplace comprising a firebox having a hearth floor, a rear wall, opposite side walls, and a front firebox opening, said fireplace having an outer housing surrounding said firebox in spaced relationship so as to form air passageways between said outer housing and each said wall and hearth of said firebox, said passageways including a front passageway opening adjacent the front edge of said hearth, said improved system, comprising: (a) at least one elongated duct extending from communication at one end with the outside air source to a position laterally adjacent the fireplace; (b) an air manifold extending horizontally substantially fully across the front of the fireplace, closely adjacent and in front of the lower, front edge of the firebox; (c) communication means through which the outside air passes from said duct into said manifold; and (d) means defining an elongated opening fully across the front of the fireplace through which the interior of said manifold communicates with the space immediately below and in front of the firebox, whereby outside air from said manifold is drawn into the firebox to support combustion, and to pass cool air beneath the hearth and to the walls of the fireplace to cool said walls, (e) a horizontal baffle means within said manifold for dividing the air into an upper layer directed towards the interior of said firebox through said front firebox opening thereof for supporting combustion, and a lower layer directed toward said front passageway opening for providing cooling air to said passageways to cool said walls of said firebox and to provide air to said firebox for combustion.