Johnson Controls Residential Gas TM9V MP - Manual (Page 4)

438335-UIM-B-0509
4 Johnson Controls Unitary Products
FURNACE LOCATION AND CLEARANCES
The furnace shall be located using the following guidelines:
1.
Where a minimum amount of air intake/vent piping and elbows will
be required.
2. As centralized with the air distribution as possible.
3. Where adequate combustion air will be available (particularly
when the appliance is not using outdoor combustion air).
4. Where it will not interfere with proper air circulation in the confined
space.
5. Where the outdoor vent terminal will not be blocked or restricted.
Refer to “VENT CLEARANCES” located in SECTION VII of these
instructions. These minimum clearances must be maintained in
the installation.
6. Where the unit will be installed in a level position with no more than
1/4” (6.4 mm) slope side-to-side and front-to-back to provide
proper condensate drainage.
Installation in freezing temperatures:
1.
Furnace shall be installed in an area where ventilation facilities
provide for safe limits of ambient temperature under normal oper-
ating conditions. Ambient temperatures must not fall below 32°F
(0°C) unless the condensate system is protected from freezing.
2. Do not allow return air temperature to be below 55º F (13°C) for
extended periods. To do so may cause condensation to occur in
the main heat exchanger, leading to premature heat exchanger
failure.
3. If this furnace is installed in an unconditioned space and an
extended power failure occurs, there will be potential damage to
the internal components. Following a power failure situation, do
not operate the unit until inspection and repairs are performed.
4. Special precautions MUST be made if installing furnace in an area
which may drop below freezing. This can cause improper opera-
tion or damage to the equipment. If the furnace is installed in an
area that has the potential of freezing, the drain line must be pro-
tected. Use a 3 to 6 watt per foot at 115 vac, 40º F (4.4°C) self-reg-
ulating, shielded and waterproof heat tape. Wrap the drain line
outside of the furnace with the heat tape and secure with ties. Fol-
low the heat tape manufacturer's recommendations.
Clearances for access/service:
Ample clearances should be provided to permit easy access to the unit.
The following minimum clearances are recommended:
1. Twenty-four (24) inches (61 cm) between the front of the furnace
and an adjacent wall or another appliance, when access is
required for servicing and cleaning.
2. Eighteen (18) inches (46 cm) at the side where access is required
for passage to the front when servicing or for inspection or replace-
ment of flue/vent connections.
In all cases, accessibility clearances shall take precedence over clear-
ances for combustible materials where accessibility clearances are
greater.
Installation in a residential garage:
A gas-fired furnace for installation in a residential garage must be
installed so the burner(s) and the ignition source are located not less
than 18” (46 cm) above the floor, and the furnace must be located or
protected to avoid physical damage by vehicles.
* 24" clearance in front and 18" on side recommended for service access.
All furnaces approved for alcove and attic installation.
SECTION II: DUCTWORK
DUCTWORK GENERAL INFORMATION
The duct system’s design and installation must:
1. Handle an air volume appropriate for the served space and within
the operating parameters of the furnace specifications.
2. Be installed in accordance of National Fire Protection Association
as outlined in NFPA standard 90B (latest editions) or applicable
national, provincial, state, and local fire and safety codes.
3. Create a closed duct system. For residential and non-HUD Modu-
lar Home installations, when a furnace is installed so that the sup-
ply ducts carry air circulated by the furnace to areas outside the
space containing the furnace, the return air shall also be handled
by a duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace.
4. Complete a path for heated or cooled air to circulate through the
air conditioning and heating equipment and to and from the condi-
tioned space.
When the furnace is used with a cooling coil, the coil must be installed
parallel with, or in the supply air side of the furnace to avoid condensa-
tion in the primary heat exchanger. When a parallel flow arrangement is
used, dampers or other means used to control airflow must be ade-
quate to prevent chilled air from entering the furnace. If manually oper-
ated, the damper must be equipped with means to prevent the furnace
or the air conditioner from operating unless the damper is in full heat or
cool position.
When replacing an existing furnace, if the existing plenum is not the
same size as the new furnace then the existing plenum must be
removed and a new plenum installed that is the proper size for the new
furnace. If the plenum is shorter than 12” (30.5 cm) the turbulent air flow
may cause the limit controls not to operate as designed, or the limit con-
trols may not operate at all.
The duct system is a very important part of the installation. If the duct
system is improperly sized the furnace will not operate properly.
The ducts attached to the furnace plenum, should be of sufficient size
so that the furnace operates at the specified external static pressure
and within the air temperature rise specified on the nameplate.
If a matching cooling coil is used, it may be placed directly on the fur-
nace outlet and sealed to prevent leakage. If thermoplastic evaporator
‘A’ coil drain pans are to be installed in the upflow/horizontal configura-
tion, then extra 2” (5.1 cm) minimum spacing may be needed to ensure
against drain pan distortion.
Improper installation in an ambient below 32ºF (0.0° C) could create
a hazard, resulting in damage, injury or death.
Liquid anti-freeze will cause damage to internal plastic parts of this
furnace. DO NOT attempt to winterize the furnace using liquid
anti-freeze.
Table 1: Unit Clearances to Combustibles
Application Upflow Downflow Horizontal
Top 1" 0" 0"
Vent 0" 0" 0"
Rear 0" 0" 0"
Side 0" 0" 1"
Front* 0" 0" 0"
Floor Combustible Combustible 1
1. For combustible floors only when used with special sub-base.
Combustible
Closet Yes Yes Yes
Line Contact No No Yes
The cooling coil must be installed in the supply air duct, down-
stream of the furnace. Cooled air may not be passed over the heat
exchanger.
The minimum plenum height is 12” (30.5 cm). The furnace will
not operate properly on a shorter plenum height. The minimum
recommended rectangular duct height is 4” (10.2 cm) attached to
the plenum.