Vent Termination Clearances For Installations In The Usa And Canada - Lennox G51MP Unit Information

exhaust pipe must be painted or wrapped to protect insula-
tion from deterioration. Exhaust pipe insulation may not be
necessary in some specific applications.
NOTE − During extremely cold temperatures, below approx-
imately 20°F (6.7°C), units with long runs of vent pipe
through unconditioned space, even when insulated, may
form ice in the exhaust termination that prevents the unit
from operating properly. Longer run times of at least 5 min-
utes will alleviate most icing problems. Also, a heating cable
may be installed on exhaust piping and termination to pre-
vent freeze−ups. Heating cable installation kit is available
from Lennox. See Condensate Piping section for part num-
bers.
C
A − Clearance above grade − 12 in. (305mm) minimum.
B − Clearance to window or door that may be opened −
for vent installations in USA − 12 in. (305mm) minimum.
for vent installations in Canada − 12 in. (305mm) minimum
for appliances  100,000 Btuh (30 kW);
36 in. (0.9m) minimum for appliances > 100,000 Btuh (30
kW).
C − Do not position terminations directly under roof eaves.
D − Clearance to electric meters, gas meters, regulators, and
relief equipment −
for vent installations in USA − 48 in (1219mm) minimum.
for vent installations in Canada − see current edition of CSA
B149 Code.
* Note −
(I) Dimensions are from the current edition of The National Fuel Gas Code − ANSI-Z223.1/NFPA 54 for USA installa-
tions. In Canada, refer to current edition of CSA B149 installation codes. Local codes or regulations may require dif-
ferent clearances.
(II) In Non-Direct Vent installations, combustion air is taken from indoors and the flue gases are discharged to the outdoors.
VENT TERMINATION CLEARANCES
FOR INSTALLATIONS IN THE USA AND CANADA*
FIGURE 26
Do not use screens or perforated metal in exhaust ter-
minations. Doing so will cause freeze−ups and may
block the terminations.
For Canadian Installations Only:
In accordance to CSA International B149 installation
codes, the minimum allowed distance between the
combustion air intake inlet and the exhaust outlet of
other appliances shall not be less than 12 inches
(305mm).
−
G51MP VENT TERMINATION
−
AIR INLET OF OTHER APPLIANCE
D
E
E − Clearance to non−mechanical air supply inlet or outlet
for vent installations in USA − 48 in. (1219mm) minimum
horizontal and below, 12 in. (305mm) minimum above.
for vent installations in Canada − 12 in. (305mm) minimum
for appliances  100,000 Btuh (30 kW);
36 in. (0.9m) minimum for appliances > 100,000 Btuh (30
kW).
F − Clearance to mechanical air supply inlet −−
for vent installations in USA − 36 in. minimum (914mm).
G − Clearance to mechanical air supply inlet −−
for vent installations in Canada − 72 in. (1829mm) mini-
mum.
H − Do not point terminations into recessed areas such as win-
dow wells, stairwells or alcoves.
J − Do not position terminations directly above a walkway.
Page 28
IMPORTANT
IMPORTANT
less than
10 ft (3.048M)
D
F
G