Trane S9V2B040U3PSBB Installer's Manual page 27

Option 2 — Top combustion air intake
If sloping the combustion air intake pipe is not possible, install a DWV
Tee as close to the furnace as possible with drain and trap to prevent
condensation from occurring in the furnace cabinet. Do not tee AC
condensate and combustion air condensate trap together.
Option 3 — Side combustion air intake
If sloping the combustion air intake pipe is not possible, install an
approved DWV Tee as close to the furnace as possible with drain and
trap.
18-CE01D1-1M-EN
F F u u r r n n a a c c e e G G e e n n e e r r a a l l I I n n s s t t a a l l l l a a t t i i o o n n
Option 2
Combustion air
exhaust
Combustion air
intake
Approved DWV Tee
Field fabricated trap
Primary drain vent stack must
terminate below the bottom of
the condensate trap
To an approved
vented drain
Option 3
Combustion air
intake
Approved DWV Tee
Field fabricated trap
Primary drain vent stack must
terminate below the bottom of
the condensate trap
To an approved
vented drain
Combustion air
exhaust
27