Page 66
Intake Piping
The EL297UHV furnace may be installed in either direct 
vent  or  non-direct vent applications.  In  non-direct  vent 
applications, when intake air will be drawn into the furnace 
from the surrounding space, the indoor air quality must be 
considered and guidelines listed in Combustion, Dilution 
and Ventilation Air section must be followed.
Follow the next two steps when installing the unit in Direct 
Vent applications,  where  combustion  air  is  taken  from 
outdoors  and  ue  gases  are  discharged  outdoors. The 
provided air intake screen must not be used in direct 
vent applications (outdoors).
1 -   Use transition solvent cement or a sheet metal screw 
to secure the intake pipe to the inlet air connector.
2 -   Route piping to outside of structure. Continue with 
installation  following  instructions  given  in  general 
guidelines  for  piping  terminations  and  intake  and 
exhaust piping terminations for direct vent sections. 
Refer to TABLE 22 for pipe sizes.
TYPICAL AIR INTAKE PIPE CONNECTIONS
UPFLOW NON−DIRECT
VENT APPLICATIONS
INTAKE
DEBRIS
SCREEN
(Provided)
NOTE - Debris screen and elbow may be rotated, so that
screen may be positioned to face forward or to either side.
Min 2”
FIGURE 25 
TYPICAL AIR INTAKE PIPE CONNECTIONS
HORIZONTAL NON−DIRECT VENT APPLICATIONS
(Horizontal Right−Hand Air Discharge Application Shown)
INTAKE
DEBRIS
SCREEN
(Provided)
OR
NOTE - Debris screen may be positioned straight out
(preferred) or with an elbow rotated to face down.
coupling
PVC pipe
Min 2”
FIGURE 26 
Follow the next two steps when installing the unit in Non-
Direct Vent applications where combustion air is taken 
from indoors or ventilated attic or crawlspace and ue ga 
ses are discharged outdoors.
1 -   Use  eld-provided  materials  and  the  factory-
provided air intake screen to route the intake piping 
as shown in FIGURE 25 and FIGURE 26. Maintain 
a  minimum  clearance  of  3”  (76mm)  around  the 
air  intake  opening.  The  air  intake  opening  (with 
the  protective  screen)  should  always  be  directed 
forward or to either side in the upow position, and 
either  straight  out  or  downward  in  the  horizontal 
position.
The air intake piping must not terminate too 
close to the ooring or a  platform.  Ensure that 
the intake air inlet will not be obstructed by 
loose insulation or other items that may clog the 
debris screen.
2 -   If intake air is drawn from a ventilated attic (FIGURE 
27)  or  ventilated  crawlspace  (FIGURE  28)  the 
exhaust  vent  length  must  not  exceed  those  listed 
in  TABLE  23.  If  3”  diameter  pipe  is  used,  reduce 
to  2”  diameter  pipe  at  the  termination  point  to 
accommodate the debris screen.
3 -   Use a sheet metal screw to secure the intake pipe 
to the connector, if desired.