0766 Draft hoods
0767 Vent connector slope
0768 Vent connector length
0769 Vent connector support
0770 Combustible clearances for vent connectors and B-vents
0771 Size of vent connector
0772 Chimney/vent connections
0773 Vent connector extends too far into chimney | 0774 Backdrafting

0775 House air flow

0776 Typical supply and return register locations

0777 Distribution components for forced air heating

0778 Factors affecting air supply

0779 Blowers - belt drive and direct drive

0780 Fan belts on furnace blowers |