SYSTEM OPERATION
11
Location Requirements and Considerations
WARNING
To prevent possible equipment damage, personal injury or
death, the following bullet points must be observed when
installing the unit.
Follow the instructions listed below when selecting a fur-
nace location. Refer also to the guidelines provided in the
Combustion and Ventilation Air Requirements
section in this
manual or the installation instructions for details.
•
Centrally locate the furnace with respect to the
proposed or existing air distribution system.
•
Ensure the temperature of the return air entering the
furnace is between 55°F and 100°F when the furnace
is heating.
•
If the furnace is installed in an application where the
typical operating sound level of a furnace is deemed
objectionable, an optional sound reduction kit is
available. Consult your local distributor for more details.
•
Provide provisions for venting combustion products
outdoors through a proper venting system. Special
consideration should be given to vent/flue pipe routing
and combustion air intake pipe when applicable.
•
80% Furnaces:
All installations must be vented in
accordance with National Fuel Gas Code, NFPA 54/
ANSI Z223.1 - lateset edition. In Canada the furnaces
must be vented in accordance with the National
Standard of Canada, CAN/CGA B149.
•
Ensure upflow or horizontal furnaces are not installed
directly on carpeting, or any other combustible material.
The only combustible material allowed is wood.
•
A special accessory subbase must be used for upright
counterflow unit installations over any combustible
material (including wood). Refer to subbase instructions
for installation details. (
NOTE:
A subbase will not be
required if an air conditioning coil is located beneath
the furnace between the supply air opening and the
combustible floor.
•
Exposure to contaminated combustion air will result
in safety and performance-related problems. Do not
install the furnace where the combustion air is exposed
to the following substances:
chlorinated waxes or cleaners
chlorine-based swimming pool chemicals
water softening chemicals
deicing salts or chemicals
carbon tetrachloride
halogen type refrigerants
cleaning solutions (such as perchloroethylene)
printing inks
paint removers
varnishes
hydrochloric acid
cements and glues
antistatic fabric softeners for clothes dryers
and masonry acid washing materials
•
Seal off a
non-direct vent
furnace if it is installed near
an area frequently contaminated by any of the above
substances. This protects the
non-direct vent
furnace
from airborne contaminants. To ensure that the enclosed
non-direct
vent
furnace has an adequate supply of
combustion air, vent from a nearby uncontaminated
room or from outdoors. Refer to the
Combustion and
Ventilation Air Requirements
section in this manual or
the installation instructions for details.
•
If the furnace is used in connection with a cooling
unit, install the furnace upstream or in parallel with
the cooling unit coil. Premature heat exchanger failure
will result if the cooling unit coil is placed ahead of the
furnace.
•
If the furnace is installed in a residential garage, position
the furnace so that the burners and ignition source are
located not less than 18 inches (457 mm) above the
floor. Protect the furnace from physical damage by
vehicles.
•
If the furnace is installed horizontally, the furnace
access doors must be vertical so that the burners fire
horizontally into the heat exchanger. Do not install the
unit with the access doors on the “up/top” or “down/
bottom” side of the furnace.
Clearances and Accessibility
Installations must adhere to the clearances to combustible
materials to which this furnace has been design certified.
The minimum clearance information for this furnace is pro-
vided on the unit’s clearance label. These clearances must
be permanently maintained. Refer to Specification Sheet for
minimum clearances to combustible materials. Clearances
must also accommodate an installation’s gas, electrical, and
drain trap and drain line connections.
NOTE:
In addition to
the required clearances to combustible materials, a mini-
mum of 24 inches service clearance must be available in
front of the unit.
A furnace installed in a confined space (i.e., a closet or utility
room) must have two ventilation openings with a total min-
imum free area of 0.25 square inches per 1,000 BTU/hr of
furnace input rating. One of the ventilation openings must be
within 12 inches of the top; the other opening must be within
12 inches of the bottom of the confined space. In a typical
construction, the clearance between the door and door frame
is usually adequate to satisfy this ventilation requirement.
Furnace Suspension
If suspending the furnace from rafters or joist, use 3/8”
threaded rod and 2”x2”x1/8” angle iron as shown in the fol
-
lowing figure. If the furnace is installed in a crawl space it
must also be suspended from the floor joist or supported by
a concrete pad. Never install the furnace on the ground or
allow it to be exposed to water. The length of rod will depend
on the application and the clearances necessary.
