INSTALLATION CONSIDERATIONS
11
•
Isolate a nondirect furnace from an area 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, posi
-
tion 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 provided on
the unit’s clearance label. These clearances must be perma
-
nently 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. If the alternate combustion air
intake or vent/flue connections are used on a 90% furnace,
additional clearances must be provided to accommodate
these connections. Refer to
Vent Flue Pipe and Combustion
Air Pipe
section in this manual or the installation instructions
for details.
NOTE:
In addition to the required clearances
to combustible materials, a minimum 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" thread
-
ed rod and 2”x2”x1/8” angle iron as shown in the following
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.
2" 2" 1/8"
ANGLE
IRON
(3
PLACES
)
X
X
GAS
PIPING
90% Suspended Furnace Shown
Existing Furnace Removal
NOTE:
When an existing furnace is removed from a venting
system serving other appliances,
the venting system may be
too large to properly vent the remaining attached appliances.
The following vent testing procedure is repro duced from the
American National Standard/National Standard of Canada
for Gas-Fired Central Furnaces ANSI Z21.47, latest edition,
CSA-2.3b, latest edition Section 1.23.1.
The following steps shall be followed with each appliance connected
to the venting system placed in operation, while any other appliances
connected to the venting system are not in operation:
a. Seal any unused openings in the venting system;
b. Inspect the venting system for proper size and horizontal pitch,
as required by the National Fuel Gas Code, ANSI Z223.1 or the
CSA B149 Installation Codes and these instructions. Determine
that there is no blockage or restriction, leakage, corrosion and
other deficiencies which could cause an unsafe condition;
c. In so far as practical, close all building doors and windows and
all doors between the space in which the appliance(s) connected
to the venting system are located and other spaces of the building.
Turn on clothes dryers and any appliance not connected to the
venting system. Turn on any exhaust fans, such as range hoods
and bathroom exhausts, so they shall operate at maximum speed.
Do not operate a summer exhaust fan. Close fireplace dampers;
d. Follow the lighting instructions. Place the appliance being in-
spected in operation. Adjust thermostat so appliance shall operate
continuously;
e. Test for draft hood equipped spillage at the draft hood relief
opening after 5 minutes of main burner operation. Use the flame
of a match or candle;
f. After it has been determined that each appliance connected to
the venting system properly vents when tested as outlined above,
return doors, windows, exhaust fans, fireplace dampers and any
other gas burning appliance to their previous conditions of use;
