International comfort products F8MXL, Installation Instructions Manual

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Specifications are subject to change without notice.
APPLIANCE APPLICATION REQUIREMENTS
Appliance operation has a significant impact on the
performance of the venting system. If the appliances are
sized, installed, adjusted, and operated properly, the venting
system and/or the appliances should not suffer from
condensation and corrosion. The venting system and all
appliances shall be installed in accordance with applicable
listings, standards, and codes.
The furnace should be sized to provide 100 percent of the
design heating load requirement plus any margin that occurs
because of furnace model size capacity increments. Heating
load estimates can be made using approved methods
available from Air Conditioning Contractors of America
(Manual J); American Society of Heating, Refrigerating, and
Air − Conditioning Engineers; or other approved engineering
methods. Excessive oversizing of the furnace could cause
the furnace and/or vent to fail prematurely. When a metal vent
or metal liner is used, the vent must be in good condition and
be installed in accordance with the vent manufacturer’s
instructions.
To prevent condensation in the furnace and vent system, the
following precautions must be observed:
1. The return − air temperature must be at least 60 _ F
(16 _ C)db except for brief periods of time during warm −
up from setback at no lower than 55 _ F (13 _ C) db or
during initial start − up from a standby condition.
2. Adjust the gas input rate per the installation instruc-
tions. Low gas input rate causes low vent gas temper-
atures, causing condensation and corrosion in the fur-
nace and/or venting system. Derating is permitted only
for altitudes above 2000 ft. (610 M).
3. Adjust the air temperature rise to the midpoint of the
rise range or slightly above. Low air temperature rise
can cause low vent gas temperature and potential for
condensation problems.
4. Set the thermostat heat anticipator or cycle rate to re-
duce short cycling.
Air for combustion must not be contaminated by halogen
compounds which include chlorides, fluorides, bromides, and
iodides. These compounds are found in many common home
products such as detergent, paint, glue, aerosol spray,
bleach, cleaning solvent, salt, and air freshener, and can
cause corrosion of furnaces and vents. Avoid using such
products in the combustion − air supply. Furnace use during
construction of the building could cause the furnace to be
exposed to halogen compounds, causing premature failure of
the furnace or venting system due to corrosion.
Vent dampers on any appliance connected to the common
vent can cause condensation and corrosion in the venting
system. Do not use vent dampers on appliances common
vented with this furnace.
ADDITIONAL VENTING REQUIREMENTS
A 4” (101 mm) round vent elbow is supplied with the furnace.
A 5 − inch (127 mm) or 6 − inch (152 mm) vent connector may
be required for some model furnaces. A field − supplied
4 − inch − to − 5 − inch (101 − 127 mm) or 4 − inch − to − 6 − inch (101
− 152 mm) sheet metal increaser fitting is required when
5 − inch (127 mm) or 6 − inch (152 mm) vent connector is used.
See Figure 35 − Figure 47 Venting Orientation for approved
vent configurations.
NOTE : Vent connector length for connector sizing starts at
furnace vent elbow. The 4 − inch vent elbow is shipped for
upflow configuration and may be rotated for other positions.
Remove the 3 screws that secure vent elbow to furnace,
rotate furnace vent elbow to position desired, reinstall screws.
The factory − supplied vent elbow does NOT count as part of
the number of vent connector elbows.
The vent connector can exit the furnace through one of 5
locations on the casing.
1. Attach the single wall vent connector to the furnace
vent elbow, and fasten the vent connector to the vent
elbow with at least two field − supplied, corrosion − resist-
ant, sheet metal screws located 180 _ apart.
NOTE : A flue extension is recommended to extend from the
furnace elbow to outside the furnace casing. If flue extension
is used, fasten the flue extension to the vent elbow with at
least two field − supplied, corrosion − resistant, sheet metal
screws located 180
_
apart. Fasten the vent connector to the
flue extension with at least two field − supplied, corrosion
resistant sheet metal screws located 180 _ apart.
2. Vent the furnace with the appropriate connector as
shown in Figure 35 − Figure 47.
3. Determine the correct location of the knockout to be re-
moved.
4. Use a hammer and screwdriver to strike a sharp blow
between the tie points and work the slug back and forth
until the slug breaks free.
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs.
Use care and wear appropriate protective clothing,
safety glasses and gloves when handling parts and
servicing furnaces.
CAUTION
!