| 126 / | HD | STOVES AND FURNACES |
| 99 R | DF | HOT-AIR FURNACES {24} |
| 110 R | ![]() | .~ Compressed air {6} |
| 110 A | DF | .~.~> Blower and air damper |
| 110 AA | DF | .~.~> Downflow of air being heated |
| 110 B | DF | .~.~> Unit heaters |
| 110 C | DF | .~.~> Gas and air mixing |
| 110 D | DF | .~.~> Unitary fan and heater |
| 110 E | DF | .~.~> Thermally actuated air-propelling means |