16
18-CD37D1-2-EN
Installer’s Guide
VENT TERMINATIONS
For
DIRECT VENT APPLICATION:
The Furnaces must be
vented to the exterior of the house and combustion air MUST
come through the inlet air pipe FROM OUTSIDE AIR.
NOTE:
BAYVENT200* accessories can be used for inlet
and outlet terminals when the pipes do not exit the
structure together.
For Canadian applications, venting systems must meet
ULC-S636 requirements.
For
NONDIRECT VENT APPLICATION:
The Furnace shall
be vented to the exterior of the house, but combustion air may
enter from the surrounding area as long as combustion air
requirements are met. (See AIR FOR COMBUSTION AND
VENTILATION)
FURNACE VENT / INLET PIPE INSTALLATION IN TWO
PRESSURE ZONE CONFIGURATIONS
There are many different variations of the vent / inlet air
pipe combination. The vent / inlet air combination used for
installation of these Furnaces depends on the needs of the
location. However, these guidelines must be followed:
1. The Furnace must vent outside the structure.
2. Furnace combustion air requirements must be met for
non-direct, single pipe applications.
3. For direct vent application of these Furnaces, the vent
pipe and air inlet pipe do not have to exit in the same
air space or even on the same surface of the structure.
However, the longest individual pipe will decide the value
for the longest allowable equivalent vent/ inlet air length
as shown in the vent length table on page 19.
NOTE: For single pressure zone applications, see Figure
30.
The following are
EXAMPLES ONLY
:
EX. 1 —
Example 1 shows that the vent may go vertical while the inlet
air may be on any side of the structure. The vent pipe would
decide the maximum equivalent length for the pipe depending
on the furnace and pipe size.
EX. 2 —
Example 2 shows the vent pipe exhausting through the roof
and the inlet air coming from the interior of the house. The inlet
air coming from the interior of the house must meet combus-
tion requirements for area, etc., as shown in the section AIR
FOR COMBUSTION AND VENTILATION in this Installer’s
Guide.
EX. 3 —
Example 3 shows the vent exiting one side of the house while
the inlet air is on the opposite side of the structure. Here
the vent pipe length must be within the allowable length for
the size of Furnace and size of the vent pipe. This example
demonstrates that the pipes do not have to exit on the same
side of the structure.
EX. 4 —
The inlet air does not have to come from outside the structure.
Example 4 shows the inlet air, may come from the attic if the
requirements for combustion air are met as shown in the sec-
tion AIR FOR COMBUSTION AND VENTILATION.
NOTE: If only the flue gas pipe is to the outside of the
structure, a straight section of pipe (long enough to exit
the Furnace cabinet) must be attached to the inlet air side
with an elbow (which is 5 to 10 equiv. ft.) installed on the
end to prevent dust and debris from falling directly into
the Furnace.
Furnace
Air
Inlet
Vent
Example 1
Furnace
Vent
Air
Inlet
(See Note)
Example 2
Furnace
Air
Inlet
Vent
Example 3
Furnace
Air
Inlet
Vent
Attic
Vent
(See Note)
Example 4
