Lennox International Inc Gas Units, G61MP Series Units Typical Exhaust Pipe Connections

TYPICAL EXHAUST PIPE CONNECTIONS

HORIZONTAL DIRECT OR NON−DIRECT VENT

APPLICATIONS

(Horizontal Right−Hand Air

Discharge Application Shown)

CAUTION

Do not discharge exhaust into an existing stack or stack that also serves another gas appliance. If verti- cal discharge through an existing unused stack is re- quired, insert PVC pipe inside the stack until the end

*2" maximum length for −110, −111 −135 only

DO NOT transition from smaller to larger pipe size in horizontal runs of exhaust pipe.

2−1/2", 3", OR 4"

TRANSITION

*2"

2"

2"

36B−045

36B−070

36B−071

48C−090

60C−090

60C−091

48C−110

60C−110*

60C−111*

60D−135*

2"

36B−045

36B−070

36B−071

36C−090

60C−090

60C−091

is even with the top or outlet end of the metal stack.

CAUTION

The exhaust vent pipe operates under positive pres- sure and must be completely sealed to prevent leak- age of combustion products into the living space.

Intake Piping

The G61MP furnace may be installed in either direct vent or non−direct vent applications. In non−direct vent applica- tions, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be consid- ered and guidelines listed in Combustion, Dilution and Ven- tilation Air section must be followed.

The G61MP unit is designed for either left−side or right−side air intake connections in either upflow or downflow applica- tions. In horizontal applications, air intake must be brought in through the top. Intake air piping is independent of ex- haust piping.

FIGURE 24

IMPORTANT

Exhaust piping and condensate trap must be installed on the same side of the unit in upflow and dowflow applications or use alternate drain kit 76M20.

2 − All horizontal runs of exhaust pipe must slope back to- ward unit. A minimum of 1/4" (6mm) drop for each 12" (305mm) of horizontal run is mandatory for drainage. Horizontal runs of exhaust piping must be supported ev- ery 5 feet (1.52m) using hangers.

NOTE − Exhaust piping should be checked carefully to make sure there are no sags or low spots.

3 − On the opposite side of the cabinet, glue the provided 2" ABS vent plug into the unused ABS flue collar with ABS or all purpose solvent cement.

4 − Route piping to outside of structure. Continue with installation following instructions given in piping ter- mination section.

Follow the next four steps when installing the unit in direct vent applications, where combustion air is taken from out- doors and flue gases are discharged outdoors. The pro- vided air intake screen must not be used in direct vent ap- plications.

1 − Use transition solvent cement to connect PVC pipe to the ABS slip connector located on the side of the burn- er box.

2 − Use a #7 sheet metal screw to secure the intake pipe to the connector, if desired. A pilot indentation is provided in the slip connector to assist in locating and starting the fas- tener.

3 − Glue the provided 2" ABS plug into the unused ABS air intake connector on the opposite side of the cabinet with ABS all pupose cement.

4 − Route piping to outside of structure. Continue with instal- lation following instructions given in general guide lines for piping terminations and in intake and exhaust piping ter- minations for direct vent sections. Refer to figure 25 for pipe sizes.

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