Lennox MERIT ML195UH Installation Instructions Manual page 33

Furnace with Evaporator
Coil Using a Common Drain
(Trap at coil is optional)
(1" min. to 2" Max.above
condensatedrain connection)
Condensate
Drain Connection
FIGURE 51
Evaporator
(Trap at coil is optional)
Drain Pan
Evaporator drain
line required
Furnace with Evaporator Coil Using a Common Drain
(Unit shown in horizontal left−hand discharge position)
Coil
Condensat e Drai n
Connection
Piping from furnace and evaporator coil must slope
down a minimum 1/4" per ft. toward trap
When combining the furnace and evaporator coil
drains together, the A/C condensate drain outlet must
be vented to relieve pressure in order for the furnace
pressure switch to operate properly.
4"min
5"max
5' max.
PVC Pipe Only
FIGURE 52
Page 33
IMPORTANT
(4" min. to 5" Max.above
condensatedrain connection)