Patent ID: 6880545

Claim:
A heating apparatus comprising: a blower box; at least one heating section wall defining a heating space in fluid communication with said blower box, said heating space having a back side proximate said blower box and an opposite facing front side disposed distal from said blower box; a plurality of vertically spaced apart pairs of spaced apart first and second heated air distribution plenums disposed in said heating space, said spaced apart first and second heated air distribution plenums having a heated air inlet opening in fluid communication with said blower box and said spaced apart pairs forming a return air conduit therebetween extending between said back side and said front side of said heating space and having a return air outlet end in fluid communication with said blower box; each of said first and second heated air distribution plenums having a substantially planar heated air distribution plate facing a space between said first and second heated air distribution plenums and having a plurality of heated air outlet openings; and a heating surface suitable for supporting an object to be heated disposed between each said spaced apart first and second heated air distribution plenums.