Bottom Return Air Opening [Upflow Models ]; Filters - Read This Section Before Installing The Return Air Ductwork - Goodman GKS9 Installation Instructions Manual

Example:
static reading from return duct = -.1" w.c.
static reading from supply duct = .3" w.c.
total external static pressure on this system = .4" w.c.
NOTE: Both readings may be taken simultaneously and read di-
rectly on the manometer if so desired. If an air conditioner coil or
Electronic Air Cleaner is used in conjunction with the furnace, the
readings must also include theses components, as shown in the
following drawing.
4. Consult proper tables for the quantity of air.
If the total external static pressure exceeds the maximum listed on
the furnace rating plate, check for closed dampers, registers, un-
dersized and/or oversized poorly laid out duct work.
Checking Static Pressure
(80% Furnace Shown, 90% Similar)
B R A O
OTTOM ETURN IR PENING
The bottom return air opening on upflow models utilizes a "lance
and cut" method to remove sheet metal from the duct opening in
the base pan. To remove, simply press out the lanced sections by
hand to expose the metal strips retaining the sheet metal over the
duct opening. Using tin snips, cut the metal strips and remove the
sheet metal to free the duct flanges. Using the scribe line along
the duct flange as a guide, unfold the duct flanges around the
perimeter of the opening using a pair of seamer pliers or seamer
tongs. NOTE: Airflow area will be reduced by approximately 18% if
duct flanges are not unfolded. This could cause performance is-
sues and noise issues.
E
DGES OF SHEET METAL HOLES MAY BE SHARP
PRECAUTION WHEN REMOVING SHEET METAL FROM DUCT OPENING
[U M ]
PFLOW ODELS
WARNING
. U
SE GLOVES AS A
CUT USING TIN SNIPS
CUT FOUR CORNERS
AFTER REMOVING SHEET
METAL
When the furnace is used in connection with a cooling unit, the
furnace should be installed in parallel with or on the upstream side
of the cooling unit to avoid condensation in the heating element.
With a parallel flow arrangement, the dampers or other means
used to control the flow of air must be adequate to prevent chilled
air from entering the furnace and, if manually operated, must be
equipped with means to prevent operation of either unit unless the
damper is in the full heat or cool position.
When the furnace is installed without a cooling coil, it is recom-
mended that a removable access panel be provided in the outlet
air duct. This opening shall be accessible when the furnace is
installed and shall be of such a size that the heat exchanger can be
viewed for visual light inspection or such that a sampling probe
can be inserted into the airstream. The access panel must be
made to prevent air leaks when the furnace is in operation.
When the furnace is heating, the temperature of the return air en-
tering the furnace must be between 55°F and 100°F.
F - R T
ILTERS EAD HIS
R A D
ETURN IR UCTWORK
Filters must be used with this furnace. Discuss filter maintenance
with the building owner. Filters do not ship with this furnace, but
must be provided by the installer. Filters must comply with UL900
or CAN/ULCS111 standards. If the furnace is installed without fil-
ters, the warranty will be voided.
On upflow units, guide dimples locate the side return cutout
locations. Use a straight edge to scribe lines connecting the
dimples. Cut out the opening on these lines. NOTE: An
undersized opening will cause reduced airflow.
.
28
PRESS OUT BY HAND
SCRIBE LINES OUTLINING
DUCT FLANGES
Duct Flange Cut Outs
S B I
ECTION EFORE NSTALLING
T
HE