Vent Pipe Installation; Pipe Routing & Support - Nordyne M2RC-080 Installation Instructions Manual

NOTE: Always use the same or larger size
piping for combustion air as is used for the
exhaust vent.
Vent Pipe Installation
Pipe Routing and Support
Route piping as directly as possible between
the furnace and the outdoors and remember
that routing affects pipe size requirements per
the preceding section. Locate the combustion
air intake and the vent exhaust in the same
atmospheric pressure zone - i.e. both must exit
the building though the same portion of exterior
wall or roof. Vent piping must be sloped upwards
not less than 1/4" per foot in the direction from
the furnace to the terminal. This is to ensure
that any condensate flows back to the furnace
(where it can be disposed of through the
condensate disposal system).
CAUTION:
Combustion air must not be drawn from
a corrosive atmosphere.
_]-he qua!ity of outdoor air must also be
considered. Be sure that the combustion air
intake is not located near a source of solvent
fumes or other chemicals which can cause
corrosion of the furnace combustion system.
Piping must be mechanically supported so that
its weight does not bear on the furnace. Supports
must be at intervals no greater than five feet,
and at smaller intervals if necessary to ensure
that there are no sagging sections to trap water
(See Figures 14 & 15).
Figure 16 illustrates vent and combustion air
pipe sizes exiting the furnace. Transition to the
correct pipe size must be done close to the
furnace so that the full length of pipe is of proper
size.
These condensing furnaces have been certified
for installation with zero clearance between
vent piping and combustible surfaces. However,
it is good practice to allow space forconvenience
in installation and service.
Pipe Couplings at the Furnace
The provided rubber couplings should be in-
stalled in the combustion air (use 3" diameter
coupling) and vent (2" diameter) pipes to allow
for servicing. These couplings are designed to
fit snugly over the pipe and be secured to the
pipes using the provided hose clamps. Use 3"
x 2" flexible coupling at furnace on 2" vent pipe
and on upflow units use 3" diameter coupling
above coil box, as shown in Figures 14 and 15.
Refer to figures 14 and 15 for the proper
installation of these couplings.
Location of Outdoor Terminations
Vent and combustion air intake terminations
must be located to ensure proper furnace
operation and to conform to applicable codes.
Figure 13 illustrates necessary distances from
the vent termination to windows andbuilding
air intakes. In Canada, the Canadian Fuel
Gas Code takes precedence over these
draft vent
termin_d /
Air Intet
Dite_ Vetlt
terminal -
more than
50,000 Btuh
Figure 13. Vent Termination Clearances
14