Sterling GG-120 User Manual

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4.  Slope horizontal runs upward 
from the gas unit heater at least 
1/4-inch per foot (21mm/m) 
m i n i m u m .  H o r i z o n t a l  Ve n t 
Connector length should not 
ex c e e d   7 5 %   o f   t h e   ve r t i c a l 
height of the vent pipe for single 
wall, or 100% of the ver tical 
height for B-Vent connectors. 
Maximum vent connector length 
is 10 feet (3m). For exceptions 
see Ch. 10 of the National Fuel 
G a s   C o d e ,   A N S I   Z 2 2 3 . 1 . 
Horizontal portions of the venting 
s y s t e m   s h a l l   b e   s u p p o r t e d 
at minimum intervals 
o f   4   fe e t   ( 1 . 2 m )   ( i n 
C a n a d a ,   s u p p o r t   a t 
3 foot inter vals  (1m) 
minimum intervals. 
5.  Use as few elbows as 
possible.
6.  Seal all vent pipe joints 
and seams to prevent 
leakage. Use General 
Electric RTV-108, Dow-
Corning RTV-732, or 
e q u i va l e n t   s i l i c o n e 
sealant with a temper-
ature rating of 500 deg. F, 
HORIZONTALLY VENTED, CATEGORY I - Figure 13 
Observe the following precautions 
when venting the unit:
1.  Use fl ue pipe of the size shown 
on Table 5. All heaters must be 
vented with a UL Listed, Type B 
or single wall vent. Refer to Table 
5 for dimensional restrictions.   
2.  E a c h   u n i t   m u s t   h a v e   a n 
individual vent pipe and vent 
terminal.  
Unit  must not be 
connected to other vent systems 
or to a chimney.
3.  A   m i n i m u m   ve r t i c a l   r i s e   i s 
required for Category I venting. 
See Table 5 for specifications. 
The vent terminal must be at 
least 3 feet (1m) above grade, 
or in snow areas, at least 3 
feet (1m) above the snow line 
to prevent blockage by snow.  
Install a weather cap over the 
vent opening. An Amer ivent 
A m e r i c a p   o r   M e t a l b e s t o s 
vent cap must be supplied by 
the customer for each power 
vented unit.
4.  Through the wall venting for these 
appliances shall not terminate 
over public walkways, or over an 
area where the condensate or 
vapor could create a nuisance, 
hazard, or could be detrimental to 
the operation of regulators, relief 
valves, or other equipment.
5.  Seal all vent pipe joints and 
seams to prevent leakage. Use 
General Electric RTV-108, Dow-
Corning RTV-732, or equivalent 
silicone sealant with a tempera-
ture rating of 500 deg. F, or 3M 
# 425 aluminum foil tape (or 
equivalent). The vent system 
must be installed to prevent 
collection of condensate. Pitch 
horizontal pipes downward 1/4 
inch per foot (21mm per meter) 
toward the outlet for condensate 
drainage. Install a tee with a 
condensate drain at the low point 
of the pipe (see Figure 13). As 
an alternate, a 3/8 inch diameter 
hole may be drilled at the low 
point of the pipe for condensate 
drainage.
6.  Horizontal portions of the venting 
system shall be suppor ted at 
minimum intervals of 4 feet (1.2m) 
to prevent sagging (in Canada, 
support at 3 foot (1m) minimum 
intervals).
8.  Avoid running vent pipe through 
unheated spaces. When this 
cannot be avoided, insulate the 
pipe to prevent condensation of 
moisture on the walls of the pipe.
VERTICALLY VENTED, CATEGORY I - Figure 12  
Observe the following precautions 
when venting the unit:
1.  Use flue pipe of the same size 
as the fl ue connection(s) on the 
gas unit heater 4" (102mm). All 
heaters must be vented with a 
UL Listed, Type B or single wall 
vent, a factory built chimney, or 
a lined brick and mortar chimney 
that has been constructed in 
accordance with the National 
Building Code. All tables and 
dimensions assume B vent for 
the fl ue and single wall pipe or B 
vent for the connector.
2.  E a c h   u n i t   m u s t   h a v e   a n 
individual vent pipe and vent 
terminal.  
Unit  must not be 
connected to other vent systems 
or to a chimney.
3.  A minimum vertical rise of 5 feet 
(1.5m) is required for Category 
I venting. The top of the vent 
pipe should extend at least 2 
feet (0.61m) above the highest 
point on the roof. Consideration 
should be made for anticipated 
snow depth.  Install an Amerivent 
Americap or Metalbestos vent 
cap over the vent opening.
or 3M #425 aluminum foil tape (or 
equivalent).
7.  Avoid running vent pipe through 
unheated spaces. When this 
cannot be avoided, insulate the 
pipe to prevent condensation of 
moisture on the walls of the pipe. 
Insulate vent pipe runs longer 
than 10 ft (3m). Insulation should 
be a minimum of 1/2" (12.7 mm) 
thick foil faced.
Figure 12
STANDARD COMBUSTION