Johnson Controls TM9X*MP installation manual UIM-B-01211, Downward Venting, Outdoor Combustion Air

697936-UIM-B-01211

DOWNWARD VENTING

In some applications, it may be necessary to run the vent pipe and air intake downwards. If this is to be done, the following rules must be fol- lowed.

•	A condensate trap hose must be connected to both the air intake
	pipe and the vent pipe at the lowest part of the horizontal run.
•	The condensate drain trap must have a trap of a minimum of six
	inches.
•	The total vertical downward distance must not exceed sixteen feet.
• The condensate drain hose must be connected to a condensate
	drain pump, a open or vented drain or into the condensate drain
	line from the furnace.
•	The condensate drain lines must not pass through unconditioned
	spaces where the temperature may fall below freezing.
•	The condensate drain line must be primed at the initial start-up

Outdoor Combustion Air

Combustion Air Intake/Vent Connections

This installation requires combustion air to be brought in from outdoors. This requires a properly sized pipe (Shown in Figure 33) that will bring air in from the outdoors to the furnace combustion air intake collar on the burner box. The second pipe (Shown in Figure 33) is the furnace vent pipe.

NOTICE

An optional plastic birdscreen is shipped in the loose parts bag with every furnace. This may be installed in the intake collar to prevent any small objects from entering the furnace.

prior to the start of heating season.

16’ MAX

6” MIN.

Connects to collar on top of burner box

Vent pipe cements into socket just above top panel

Or vent pipe may be clamped into outlet of drain coupling

6” MIN.

FIGURE 33: Downward Venting

COMBUSTION AIR SUPPLY

All installations must comply with Section 5.3, Air for Combustion and Ventilation of the National Fuel Gas Code, ANSI Z223.1 or Sections 7.2, 7.3 or 7.4 of CAN/CGA B149.1 or .2 Installation Code - latest edi- tions.

This furnace is certified to be installed with one of three possible com- bustion air intake configurations.

1.	OUTDOOR COMBUSTION AIR: This is a direct vent configuration
	where the combustion air is supplied through a PVC or ABS pipe
	that is connected to the PVC coupling attached to the furnace and
	is terminated in the same atmospheric zone as the vent. This type
	of installation is approved on all models. Refer to Figure 33.
2.	AMBIENT COMBUSTION AIR: Combustion air is supplied from
	the area surrounding the furnace through openings in the furnace
	casing. The combustion air and the vent pipes are not terminated in

FIGURE 34: Direct Vent Air Intake Connection and Vent Connection

The combustion air intake pipe should be located either through the wall (horizontal or side vent) or through the roof (vertical vent). Care should be taken to locate side vented systems where trees or shrubs will not block or restrict supply air from entering the terminal.

Also, the terminal assembly should be located as far as possible from a swimming pool or a location where swimming pool chemicals might be stored. Be sure the terminal assembly follows the outdoor clearances listed in Section #1 “Outdoor Air Contaminants.”

Ambient Combustion Air Supply

This type installation will draw the air required for combustion from within the space surrounding the appliance and from areas or rooms adjacent to the space surrounding the appliance. This may be from within the space in a non-confined location or it may be brought into the furnace area from outdoors through permanent openings or ducts. It is not piped directly into the furnace. A single, properly sized pipe from the furnace vent connector to the outdoors must be provided. It is recom- mended that the supplied intake coupling & 18” of pipe be attached to the furnace to prevent accidental blockage of the combustion air intake.

the same atmospheric zone. Refer to Figure 28 for vent termina-

tions. Refer to "Ambient Combustion Air Supply" for proper installa-

tion. Refer to Figure 34.

3. VENTILATED COMBUSTION AIR: Combustion air is supplied

through a PVC or ABS pipe that is connected to the PVC coupling

attached to the burner box and is terminated in a ventilated attic or

crawl space. The combustion air and the vent pipes are not termi-

nated in the same atmospheric zone. Refer to Figure 36 for attic

and crawl space termination. Only the combustion air intake may

terminate in the attic. The vent must terminate outside.

COMBUSTION AIR

Vent pipe cements into socket just above top panel

Or vent pipe may be clamped into outlet of drain coupling

FIGURE 35: Combustion Airflow Path Through The Furnace Casing

Johnson Controls Unitary Products 25