Installation, Operation & Maintenance Manual
Bosch 96% AFUE Gas Furnace
| 31
Bosch Thermotechnology Corp.
|
04.2019
Data subject to change
Figure 27
VENT
2”
MIN.
COMBUSTION AIR
Double Horizontal Combustion Air Intake and Vent Termination
Figure 28
MIN.
6”
Exhaust
Double Vertical Combustion Air Intake and Vent Termination
8.6 Combustion & Ventilation Air Requirements
8.6.1 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 editions.
This furnace is certifi ed to be installed with one of three possible combustion air
intake confi gurations.
1. Outdoor Combustion Air:
This is a direct vent confi guration 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 29.
2. Ambient Combustion Air:
Combustion air is supplied from the area surrounding the furnace through
openings in the furnace cabinet. The combustion air and the vent pipes are
not terminated in the same atmospheric zone. Refer to Figure 24 for vent
terminations. Refer to Section "Ambient Combustion Air Supply" for proper
installation. Refer to Figure 30 and 31.
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 terminated
in the same atmospheric zone. Refer to Figure 31 for attic and crawl space
termination. Only the combustion air intake may terminate in the attic. The
vent must terminate outside.
8.6.2 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 29) 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 29) is the furnace vent pipe.
Figure 29
Air Intake
Exhaust
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
Table 9.
8.6.3 Ambient Combustion Air
This type of 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-confi ned
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 fi eld
supplied.
WARNING: CARBON MONOXIDE POISONING HAZARD
It is recommended that the supplied intake coupling
and 18” of pipe be attached to the furnace to prevent
accidental blockage of the combustion air intake.
Figure 30
COMBUSTION AIR
Combustion Air
fl
ow Path Through The Furnace Cabinet
