Page 11
Pub. No. 41-5010-20
Installation Instructions
GENERAL VENTING INSTRUCTIONS
VENT PIPING
These furnaces have been classified as Fan-Assisted Combustion
System, Category I furnaces under the “latest edition” provisions
of ANSI Z21.47 and CAN/CGA 2.3 standards. Category I furnaces
operate with a non-positive vent static pressure and with a flue
loss of not less than 17 percent.
NOTE:
If desired, a sidewall termination can be accomplished through
the use of an “add-on” draft inducer. The inducer must be in-
stalled according to the inducer manufacturer’s instructions. Set
the barometric pressure relief to achieve -0.02 inch water column.
NOTE:
When the downflow furnace is vented through the left side of
the furnace cabinet using the provided cutout, Type B vent
piping must be used.
The furnace shall be connected to a factory built chimney
or vent complying with a recognized standard, or a ma-
sonry or concrete chimney lined with a lining material
acceptable to the authority having jurisdiction.
▲
WARNING
!
Furnace venting into an unlined masonry chimney or con-
crete chimney is prohibited. Failure to follow this warning
could result in property damage, personal injury, or death.
VENTING INTO A MASONRY CHIMNEY
If the chimney is oversized, the liner is inadequate, or flue-gas
condensation is a problem in your area, consider using the
chimney as a pathway or chase for type “B” vent or flexible vent
liner. If flexible liner material is used, size the vent using the “B”
vent tables, then reduce the maximum capacity by 20% (multiply
0.80 times the maximum capacity).
Internal Masonry Chimneys
Venting of fan assisted appliances into a lined, internal masonry
chimney is allowed only if it is common vented with at least one
natural draft appliance;
OR
, if the chimney is lined with type “B”,
double wall vent or suitable flexible liner material (See Table 7).
▲
WARNING
!
The chimney liner must be thoroughly inspected to insure no
cracks or other potential areas for flue gas leaks are present in the
liner. Liner leaks will result in early deterioration of the chimney.
Failure to follow this warning could result in carbon monox-
ide poisoning or death.
TABLE 7
* Flexible chimney liner size is determined by using the type “B” vent size for the
available BTUH input, then reducing the maximum capacity by 20% (multiply
maximum capacity times 0.80). The minimum capacity is the same as shown in
the “B” vent tables.
Internal
Type Furnace
Single Fan
Assist
Fan Assist
+
Fan Assist
Fan Assist
+
Natural
No
No
Yes
Tile Lined Chimney
No
No
No
External
Yes
Yes
Yes
“B” Vent
Flexible Metal
Chimney Lining
Yes*
Yes*
Yes*
MASONRY CHIMNEY VENTING
πππππ
(D*)
2
4
=
X 7
External Masonry Chimney
Venting of fan assisted appliances into external chimneys (one or
more walls exposed to outdoor temperatures), requires the chim-
ney be lined with type “B”, double wall vent or suitable flexible
chimney liner material. This applies in all combinations of com-
mon venting as well as for fan assisted appliances vented alone.
▲
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow the installation instructions for the venting
system being placed into operation could result in carbon
monoxide poisoning or death.
The following installation practices are recommended to mini-
mize corrosion caused by condensation of flue products in the
furnace and flue gas system.
1. Avoid an excessive number of bends.
2. Horizontal runs should pitch upward at least 1/4" per foot.
3. Horizontal runs should be as short as possible.
4. All vent pipe or connectors should be securely supported and
must be inserted into, but not beyond the inside wall at the
chimney vent.
5. When vent connections must pass through walls or partitions
of combustible material, a thimble must be used and installed
according to local codes.
6. Vent pipe through the roof should be extended to a height
determined by National Fuel Gas Code or local codes. It should
be capped properly to prevent rain water from entering the vent.
Roof exit should be waterproofed.
7. Use type “B” double wall vent when vent pipe is routed
through cool spaces (below 60° F).
8. Where long periods of airflow are desired for comfort, use long
fan cycles instead of continuous airflow.
9. Apply other good venting practices as stated in the venting
section of the National Fuel Gas Code ANSI Z223.1 “latest
edition”. (Reference CATAGORY 1 Venting Guide, Pub. No.
18-CH23D1-2 for additional information).
10.
Vent connectors serving appliance vented by natural
draft or non-positive pressure shall not be connected into
any portion of a mechanized draft system operating under
positive pressure.
11. Horizontal pipe runs must be supported by hangers, straps or
other suitable material in intervals at a minimum of every 3 feet
of pipe.
12. A furnace shall not be connected to a chimney or flue serving
a separate appliance designed to burn solid fuel.
13. The flow area of the largest section of vertical vent or chimney
shall not exceed 7 times the smallest listed appliance categorized
vent area, flue collar area, or draft hood outlet area unless designed
in accordance with approved engineering methods.
Maximum Vent or Tile
Lined Chimney Flow Area
*Drafthood outlet diameter, flue collar diameter, or listed appliance categorized vent diameter.
