34 FURNACES, BOILERS, WATER HEATERS, AND BURNERS AND ACCESSORIES THEREFOR AND PARTS THEREOF, AND AIR CONDITIONING APPARATUS-NAMELY, ROOM TYPE UNITS FOR COOLING, HUMIDIFYING, FILTERING AND CIRCULATING AIR, FOR USE IN HOMES, HOSPITALS, HOTELS, AND OFFICES; AND AIR CONDITIONING FLUID FUEL BURNING FURNACES FOR HEATING, HUMIDIFYING, FILTERING, AND CIRCULATING AIR IN BUILDINGS, AND COMPONENT PARTS THEREOF