11
Proper air flow is required for the correct operation of this
furnace. Restricted air flow can cause erratic operation
and can damage the heat exchanger. The duct system
must carry the correct amount of air for heating and cool-
ing if summer air conditioning is used.
IMPORTANT: When using outside air, design and adjust
the system to maintain a return air temperature ABOVE
55° F during the heating season.
NOTE: Return air grilles and warm air registers must not
be obstructed or closed.
UPFLOW INSTALLATIONS
1. Position the unit to minimize long runs of duct or runs
of duct with many turns and elbows.
2. For side return: Cut an opening in the side. The
opening should be cut the full width and height of the
knockouts on the unit. See Figure 6.
3. If summer air conditioning is desired, position the
indoor coil on the supply-air side of the unit. Ensure
that no air can bypass the coil.
4. Connect the furnace to the supply air plenum. See
Figure 7.
5. Connect the return air ducting to the return-air open-
ing at the bottom and/or side of the unit. Make the
connections air-tight to prevent the migration of toxic
fumes and odors including carbon monoxide from mi-
grating into the living space.
6. If a filter is installed near the furnace, be sure to have
adequate space for installation and removal of the
unit filter.
7. NOTE: Where the maximum airflow is 1800 CFM or
more, BOTH sides or the bottom must be used for the
return air. Do not take return air from the back of the
unit.
NOTE: DO NOT take return air from furnace rooms, ga-
rages or cold areas. Avoid return air from utility rooms,
kitchens, laundry rooms and bathrooms.
DUCTING
Ducting
WARNING
BLOWER AND BURNERS MUST NEVER BE OPERATED
WITHOUT THE BLOWER DOOR IN PLACE. THIS IS TO
PREVENT DRAWING GAS FUMES (WHICH COULD CON-
TAIN HAZARDOUS CARBON MONOXIDE) INTO THE
HOME THAT COULD RESULT IN PERSONAL INJURY OR
DEATH.
WARNING
THE SOLID METAL BASE PLATE MUST BE IN-
STALLED IN THE FURNACE BOTTOM WHEN USING
SIDE AIR RETURN. FAILURE TO INSTALL A BASE
PLATE COULD CAUSE THE PRODUCTS OF COM-
BUSTION TO CIRCULATE INTO THE LIVING SPACE
AND CREATE POTENTIAL LY HAZARDOUS CONDI-
TIONS, INCLUDING CARBON MONOXIDE POISON-
ING OR DEATH. FOR BOTTOM RETURN, A SOLID
METAL BASE PAN MUST NOT BE INSTALLED. SEE
FIGURE 5.
!
WARNING
SOME HEATING AIRFLOW VALUES MAY BE
HIGHER THAN THOSE REQUIRED FOR COOLING.
BE SURE TO SIZE DUCT FOR THE MAXIMUM POS-
SIBLE AIRFLOW VALUE.
SIZE AIRFLOW DISTRIBUTION SYSTEM TO AC-
CEPTABLE INDUSTRY STANDARDS AND METH-
ODS. TOTAL STATIC PRESSURE DROP OF THE
AIR DISTRIBUTION SYSTEM SHOULD NOT EX-
CEED .8 INCHES W.C. THIS WILL INCLUDE ANY
AIR CONDITIONER COIL, AIR FILTRATION SYS-
TEM, ZONING SYSTEM, DUCTWORK, ETC. REFER
TO ADDED EQUIPMENT TECHNICAL INFORMA-
TION TO OBTAIN PRESSURE DROP INFORMATION
WHEN EQUIPMENT IS OPERATING AT RECOM-
MENDED HEATING OR COOLING CFMS.
!
WARNING
ZONING SYSTEMS ARE NOT DIRECTLY SUPPORTED
IN THIS MANUAL. IF A THIRD PARTY SYSTEM IS USED
REFER TO THE MANUFACTURER OF THAT PRODUCT
FOR INSTALLATION AND OPERATION INSTRUCTIONS.
ZONING SYSTEMS USED ON THIS PRODUCT MUST
HAVE SENSORS TO PREVENT FURNACES AND/OR
HEATING ELEMENTS FROM CYCLING ON INTERNAL
LIMIT CONTROLS. THE ZONING SYSTEM MUST NOT
ALLOW THE EVAPORATOR COILS AND/OR HYDRONIC
COILS TO FREEZE.
!
!