9
around doors and windows. These changes have helped in
reducing heating/cooling costs but have created a problem
supplying combustion and ventilation air for gas fired and
other fuel burning appliances. Appliances that pull air out
of the house (clothes dryers, exhaust fans, fireplaces, etc.)
increase the problem by starving appliances for air.
House depressurization can cause back drafting or improper
combustion of gas-fired appliances, thereby exposing
building occupants to gas combustion products that could
include carbon monoxide.
If this furnace is to be installed in the same space with
other gas appliances, such as a water heater, ensure there
is an adequate supply of combustion and ventilation air for
the other appliances. Refer to the latest edition of the
National Fuel Gas Code NFPA 54/ANSI Z223.1 or CAN/CSA
B149.1-15 Installation Codes or applicable provisions of the
local building codes for determining the combustion air
requirements for the appliances.
Most homes will require outside air be supplied to the furnace
area by means of ventilation grilles or ducts connecting
directly to the outdoors or spaces open to the outdoors such
as attics or crawl spaces.
I
NSTALLATION
P
OSITIONS
This furnace may be installed in an upright position or
horizontal on either the left or right side panel. Do not
install this furnace on its back. For
upright upflow
furnaces,
return air ductwork may be attached to the side panel(s)
and/or basepan. For
horizontal upflow
furnaces, return air
ductwork must be attached to the basepan. For both
upright
or horizontal counterflow
furnaces, return ductwork must
be attached to the basepan (top end of the blower
compartment).
NOTE:
Ductwork must never be attached
to the back of the furnace. Contact your distributor for
proper airflow requirements and number of required
ductwork connections. Refer to “Recommended Installation
Positions” figure for appropriate installation positions,
ductwork connections, and resulting airflow arrangements.
H
ORIZONTAL
A
PPLICATIONS
& C
ONSIDERATIONS
When installing a furnace horizontally, additional
consideration must be given to the following:
F
URNACE
S
USPENSION
If suspending the furnace from rafters or joists, use 3/8"
threaded rod and 2”x2”x1/8” angle iron as shown in the
following diagram. The length of rod will depend on the
application and the clearances necessary.
If the furnace is installed in a crawl space it must 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.
2" 2" 3/8"
ANGLE
IRON
(3
PLACES
)
X X
Figure 2
F
RONT
C
OVER
P
RESSURE
S
WITCH
T
UBE
L
OCATION
When a furnace is installed horizontally with left side down
the front cover pressure switch tube must be re-located to
the lower port of the collector box cover.
1. Remove tube from front cover pressure switch and
collector box cover.
2. Remove rubber plug from bottom collector box port
and install on top collector box port.
3. Locate 24” x 1/4” tube in bag assembly.
4. Install one end on front cover pressure switch.
5. Route tube to lower port on collector box cover and
cut off excess tubing.
D
RAIN
T
RAP
AND
L
INES
In horizontal applications the condensate drain trap is secured
to the furnace side panel, suspending it below the furnace.
A minimum clearance of 5 ½” below the furnace must be
provided for the drain trap. Additionally, the appropriate
downward piping slope must be maintained from the drain
trap to the drain location. Refer to
Condensate Drain Trap
and Lines
for further details. If the drain trap and drain line
will be exposed to temperatures near or below freezing,
adequate measures must be taken to prevent condensate
from freezing.
L
EVELING
Leveling ensures proper condensate drainage from the heat
exchanger. For proper flue pipe drainage, the furnace must
be level lengthwise from end to end. The furnace should
have a slight tilt from back to front with the access doors
downhill from the back panel approximately 1/2 to 3/4 inches.
The slight tilt allows the heat exchanger condensate,
generated in the recuperator coil, to flow forward to the
recuperator coil front cover.
A
LTERNATE
V
ENT
/F
LUE
AND
C
OMBUSTION
A
IR
C
ONNECTIONS
In horizontal installations provisions for alternate flue and
combustion air piping are available for upflow furnaces with
