Ducting; Upflow Installations - Rheem 801S Series Installation Instructions Manual

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 cooling if
summer air conditioning is used.
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 EXCEED .8
INCHES W.C. THIS WILL INCLUDE ANY AIR CONDI-
TIONER COIL, AIR FILTRATION SYSTEM, ZONING
SYSTEM, DUCTWORK, ETC. REFER TO ADDED
EQUIPMENT TECHNICAL INFORMATION TO OBTAIN
PRESSURE DROP INFORMATION WHEN EQUIP-
MENT IS OPERATING AT RECOMMENDED HEAT-
ING OR COOLING CFMS.
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.
WARNING
THE SOLID METAL BASE (SHIPPED WITH THE 801P
FURNACE) PLATE MUST BE INSTALLED IN THE
FURNACE BOTTOM WHEN USING SIDE AIR RE-
TURN. FAILURE TO INSTALL A BASE PLATE COULD
CAUSE THE PRODUCTS OF COMBUSTION TO CIR-
CULATE INTO THE LIVING SPACE AND CREATE
POTENTIAL LY HAZARDOUS CONDITIONS, INCLUD-
ING CARBON MONOXIDE POISONING OR DEATH.
FOR BOTTOM RETURN, A SOLID METAL BASE PAN
MUST NOT BE INSTALLED. SEE FIGURE 5.

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 open-
ing 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 in-
door 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 Fig-
ure 7.
5. Connect the return air ducting to the return-air opening
at the bottom and/or side of the unit. Make the connec-
tions air-tight to prevent the migration of toxic fumes
and odors including carbon monoxide from migrating
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,
garages or cold areas. Avoid return air from utility rooms,
kitchens, laundry rooms and bathrooms.
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.

DUCTING

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