Abstract: A novel horizontal-vertical (H-V) direct vented gas heating unit comprises a box-shaped heating unit having seven walls which surround a combustion chamber. One of the seven walls comprises a diagonal wall connected between the back vertical wall and the top wall. An exhaust stack extends through the diagonal wall and is surrounded at its exit by a coaxial fresh air inlet adapter which connects to a fresh air passageway which extends down the back wall. An inner heat exchanger comprise passageways which extend along six of the seven walls outside the combustion chamber. The fresh air passageway on the back wall extends through the heat exchanger passageway in the back wall and enters a plenum having two exits, one of which is positioned opposite the upper level and the other opposite the lower level of a dual level burner.

Abstract: Method and means for enhancing the visible length and color of high efficiency gas flames in an artificial gas log fireplace/gas burner system is characterized by selecting from a plurality of metallic salt compounds, compounds having a low melting point and the ability to exhibit light in the visible spectrum when the metallic salt compounds absorb energy from a gas flame. The metallic salt compounds are placed in a high temperature area of the burner system adjacent the gas flames so that at the melting point of the metallic salt an ionized vapor is generated which is directed into the path of the combustion air being supplied to the gas burner. The energy level of the ionized metallic salt compounds are elevated and when subsequently cooled, they emit light in the visible spectrum which combines with the gas flames and colors the invisible flame spectrum so that the invisible gas flames become visible and appear longer and exhibit natural colors.