Ducting - Rheem RGFG Installation Instructions Manual

DUCTING

Proper airflow is required for the correct
operation of this furnace.
Too little airflow can cause erratic oper-
ation and can damage the heat
exchanger. The supply and return duct
must carry the correct amount of air for
heating and cooling if summer air con-
ditioning is used.
Size the ducts according to acceptable
industry standards and methods. The
total static pressure drop of the supply
and return duct should not exceed 0.2"
w.c.
WARNING
NEVER ALLOW THE PRODUCTS
OF COMBUSTION FROM THE
FLUE TO ENTER THE RETURN
AIR DUCTWORK OR THE CIRCU-
LATED AIR SUPPLY. ALL RETURN
DUCTWORK MUST BE ADE-
QUATELY SEALED AND
SECURED TO THE FURNACE
WITH SHEET METAL SCREWS;
AND JOINTS, TAPED. SECURE
ALL OTHER DUCT JOINTS WITH
APPROVED CONNECTIONS AND
SEAL AIRTIGHT. WHEN A FUR-
NACE IS MOUNTED ON A PLAT-
FORM WITH RETURN THROUGH
THE BOTTOM, IT MUST BE
SEALED AIRTIGHT BETWEEN
THE FURNACE AND THE RETURN
AIR PLENUM. THE FLOOR OR
PLATFORM MUST PROVIDE
PHYSICAL SUPPORT OF THE
FURNACE WITHOUT SAGGING,
CRACKS, OR GAPS AROUND THE
BASE, PROVIDING A SEAL
BETWEEN THE SUPPORT AND
THE BASE.
FIGURE 5
BOTTOM PANEL REMOVAL
NOTE: FILTER AND FILTER-ROD ARE SHIPPED
ON TOP OF SOLID BOTTOM. REMOVE FILTER
AND FILTER ROD TO ACCES SOLID BOTTOM
FAILURE TO PREVENT PROD-
UCTS OF COMBUSTION FROM
BEING CIRCULATED INTO THE
LIVING SPACE CAN CREATE
POTENTIALLY HAZARDOUS CON-
DITIONS, INCLUDING CARBON
MONOXIDE POISONING THAT
COULD RESULT IN PERSONAL
INJURY OR DEATH.
DO NOT, UNDER ANY CIRCUM-
STANCES, CONNECT RETURN OR
SUPPLY DUCTWORK TO OR
FROM ANY OTHER HEAT PRO-
DUCING DEVICE SUCH AS A
FIREPLACE INSERT, STOVE, ETC.
DOING SO MAY RESULT IN FIRE,
CARBON MONOXIDE POISONING,
EXPLOSION, PERSONAL INJURY
OR PROPERTY DAMAGE.
IMPORTANT: Some high efficiency filters
have a greater than normal resistance to
airflow. This can adversely affect furnace
operation. Be sure to check airflow if
using any filter other than the factory-pro-
vided filter.
UPFLOW UNITS
1. Position the unit to minimize long
runs of duct or runs of duct with
many turns and elbows.
WARNING
UPFLOW FURNACE: A SOLID METAL
BASE PLATE MUST BE INSTALLED IN
THE FURNACE BOTTOM WHEN USING
SIDE AIR RETURN. FAILURE TO
INSTALL A BASE PLATE COULD
CAUSE THE PRODUCTS OF COMBUS-
TION TO CIRCULATE INTO THE LIVING
SPACE AND CREATE POTENTIALLY
HAZARDOUS CONDITIONS, INCLUD-
ING CARBON MONOXIDE POISONING
OR DEATH.
2. Open the return air compartment.
a. If using side return air, do not
remove the bottom base.
b. Cut an opening in the side .
The opening should be cut the
full width of the knockouts on
the unit.
NOTE: When using side
return, return air plenums,
RXGR-C17B, C21B and C24B
are available from the factory.
c. Remove the bottom base, if
using bottom return air.
Remove the panel by remov-
ing the two screws attaching
the base to the front base
angle. See Figure 5.
NOTE: Where the maximum
airflow is 1800 CFM or more,
both sides or the bottom must
be used for return air.
3. Connect the return duct or return
air cabinet to the unit. Make the
connection air tight to prevent
entraining combustion gases from
an adjacent fuel-burning appli-
ance.
4. Be sure to have adequate
space for the unit filter.
NOTE: DO NOT take return air
from bathrooms, kitchens, furnace
rooms, garages, utility or laundry
rooms, or cold areas. DO NOT
use a rear air return.
5. If summer air conditioning is
desired, position the indoor coil on
the supply air side of the unit.
Insure that no air can bypass this
coil.
6. Connect the supply air plenum to
the furnace plenum opening.
IMPORTANT: If a flexible duct
connector must be used, it MUST
be rated for a minimum tempera-
ture of 250°F. continuous.
ADS-5422-01
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