Fireplace heating unit

A fireplace heating unit comprising, a firebox including top, bottom, back and side walls, a housing spaced from and surrounding said firebox, partition means mounted in the space between said firebox and said housing and surrounding said firebox on at least five sides thereby defining an inner air chamber between the firebox and one side of the partition means and an outer air chamber between the opposite side of said partition means and said housing, outside air inlet means connected to said partition means and communicating with said inner air chamber, whereby the incoming outside air is preheated by the firebox, heated air outlet means connected to said inner chamber and communicating with the room to be heated, heated air inlet means connected to said firebox and communicating with said inner air chamber, whereby a portion of the incoming heated outside air is used as combustion air;

• room air inlet and outlet means connected to the outer chamber, whereby room air is only circulated through said outer chamber, and insulation means mounted on and substantially covering said partition means to thereby maintain the air in the inner chamber at an extremely high temperature, whereby the heat conducted from the firebox walls to the air in the inner chamber, and the insulation means maintaining the heat in the inner chamber causes the combustion air to reach a temperature high enough to ignite the exhaust gases in the firebox to thereby eliminate exhaust smoke.