Lennox EL180UH060NE36A - General Venting Requirements; Venting Rules and Tables

Page 14
Do not install a manual damper, barometric draft regulator,
or ue restrictor between the furnace and the chimney.
Never connect a Category I appliance to a chimney that is
servicing a solid-fuel appliance. If a replace chimney ue
is used to vent this appliance, the replace opening must
be permanently sealed.
A type B or listed chimney lining system that passes
through an unused masonry chimney ue is not consid-
ered to be exposed to the outdoors.
General Venting Requirements
Vent all EL180UHNE furnaces according to these instruc-
tions:
1 - Vent diameter recommendations and maximum
allowable piping runs are found in the provided
venting tables.
2 - In no case should the vent or vent connector diameter
be less than the diameter specied in the provided
venting tables.
3 - The minimum vent capacity determined by the sizing
tables must be less than the low re input rating and
the maximum vent capacity must be greater than the
high re input rating.
4 - Single appliance vents - If the vertical vent or tile-
lined chimney has a larger diameter or ow area than
the vent connector, use the vertical vent diameter to
determine the minimum vent capacity and the vent
connector diameter to determine the maximum vent
capacity. The ow area of the vertical vent, however,
shall not exceed 7 times the ow area of the listed
appliance categorized vent area, drafthood outlet
area or ue collar area unless designed according to
approved engineering methods.
5 - Multiple appliance vents - The ow area of the largest
section of vertical vent or chimney shall not exceed
7 times the smallest listed appliance categorized
vent area, drafthood outlet area or ue collar area
unless designed according to approved engineering
methods.
6 - The entire length of single wall metal vent connector
shall be readily accessible for inspection, cleaning,
and replacement.
7 - Single appliance venting congurations with zero
lateral lengths (TABLE 3) are assumed to have
no elbows in the vent system. For all other vent
congurations, the vent system is assumed to have
two 90° elbows. For each additional 90° elbow or
equivalent (for example two 45° elbows equal one
90° elbow) beyond two, the maximum capacity listed
in the venting table should be reduced by 10% (0.90
x maximum listed capacity).
8 - The common venting TABLE 4 and TABLE 5
were generated using a maximum horizontal vent
connector length of 1-1/2 feet (.46 m) for each inch
(25 mm) of connector diameter as follows:
TABLE 2
Connector Diameter
inches (mm)
Maximum Horizontal
Connector Length feet (m)
3 (76) 4-1/2 (1.37)
4 (102) 6 (1.83)
5 (127) 7-1/2 (2.29)
6 (152) 9 (2.74)
7 (178) 10-1/2 (3.20)
Common Venting Using Tile-Lined Interior Masonry Chimney and Combined Vent Connector
MINIMUM LENGTH = AS SHORT AS PRACTICAL.
FOR MAXIMUM LENGTH SEE NOTE TO LEFT
INTERIOR TILE-LINED
MASONRY CHIMNEY
NOTE - the chimney must be properly
sized per provided venting tables or
lined with listed metal lining system.
PERMANENTLY
SEALED FIREPLACE
OPENING
VENT
CONNECTOR
NOTE- Refer to provided venting tables
for installations.
FURNACE
OTHER
APPLIANCE
AIR FLOW
FIGURE 17