Part number 550-100-090/0809
gas
-
fired
water
boiler
—
Boiler Manual
66
Sidewall vent/air termination:
Separate pipes
Allowable vent/air pipe materials
Use only the materials listed in
1.
Figure 12, page 17.
Purchase termination plates and bird screens separately. See the
2.
parts list at the end of this manual.
Maximum piping length
Locate the terminations such that the total air piping and vent pip-
1.
ing from the boiler to the termination will not exceed the maximum
length given in Figure 74.
Maximum lengths listed in
2.
Figure 74 allow for 2 elbows. Additional
elbows required a reduction in maximum length as explained in
the table notes.
Connecting from termination to boiler
Install the terminations as instructed in the following. Then pro-
1.
ceed to page 75 to complete the air and vent piping between the
termination and the boiler.
Determine location — separate elbows
A gas vent extending through an exterior wall shall not
terminate adjacent to the wall or below building exten-
sions such as eaves, parapets, balconies or decks. Failure
to comply could result in severe personal injury, death
or substantial property damage.
Locate the vent/air terminations using the following guidelines.
1.
The air piping must terminate in a down-turned elbow as shown in
2.
Figure 75. This arrangement avoids recirculation of flue products
into the combustion air stream.
Apply the configuration on the left side of
a.
Figure 75 unless
the terminations would fail to meet minimum clearance to
grade or snow line.
Apply the configuration on the right side of
b.
Figure 75 when
the terminations need to be raised higher to meet clearance to
grade or snow line.
The vent and air pipes may run up as high as 4 feet, as shown in
c.
Figure 75 right side with no enclosure. The vent and air pipes
must be secured with braces, and all clearances and lengths
must be maintained. Space braces no further than 24 inches
apart. (See WARNING below for extremely cold climates.)
External venting greater than 4 feet requires an insulated enclo-
d.
sure around the vent and air pipes. The vent and air termina-
tions must exit through the enclosure as shown in Figure 75,
maintaining all required clearances.
The vent piping must terminate in an elbow pointed outward or
3.
away from the air inlet, as shown in Figure 75.
Do not exceed the maximum lengths of the outside vent
piping shown in Figure 75. Excessive length exposed to
the outside could cause freezing of condensate in the vent
pipe, resulting in potential boiler shutdown. In extremely
cold climates, install an insulated chase around the vent
piping, particularly when using longer lengths. The chase
must allow for inspection of the vent pipe, and insulation
must be protected from water.
Maximum piping lengths for separate vent
Figure 74
and air pipe sidewall termination
Boiler
Ultra–
Maximum
Piping, 2” *
Maximum
Piping, 3” *
Maximum
Piping, 4” *
Feet
Elbows
Feet
Elbows
Feet
Elbows
80 **
100
2
100
2
Not
allowed
105 **
100
2
100
2
155
Not allowed
100
2
230
Not allowed
30
2
100
2
299
Not allowed
Not allowed
100
2
399
Not allowed
Not allowed
100
2
* Install pipe reducers to adapt from pipe size used to the out-
side diameter required at the boiler You do not have to reduce
allowable pipe length for the reducers
** Ultra-80 and 105 boilers installed with 2-inch vent piping
automatically derate due to the pressure loss in the vent and
air piping The derate ranges up to 10% for the Ultra-80 at 100
feet or 15% for the Ultra-105 at 100 feet
For piping using more than 2 elbows, reduce maximum allow-
able length:
• 7 feet for each additional 4-inch elbow (90° or 45°)
• 7 feet for each additional 2 or 3-inch long radius elbow
• 16 feet for each 2 or 3-inch short radius elbow
• 7 feet for each 2 or 3-inch 45-degree elbow.
Sidewall termination — separate pipes
Figure 75
— configuration options and minimum
clearances from vent to air terminations