2 in intake/vent nominal pipe, 19-1/2 in L air inlet pipe
Note: the Concentric vent reduces the allowable intake/vent piping length by 5 ft from that listed in the basic furnace installation instructions
The combustion air and vent pipe fittings must conform ANSI and ASTM standards D1785, F891, D2665, D2241, D2661, or F628, pipe cement and primer must conform to ASTM standards D2564 or D2235
In Canada, construct all combustion air and vent pipes for this units of CSA or ULC certified Schedule 40 PVC, PVC-DWV, or ABS-DWV pipe and pipe cement