Dunkirk XEB-3 Installation, Operation & Maintenance Manual page 17

1,
,
3,
,
5,
These boilers may be vented horizontally as shown in
Figure 10. The vent pipe is pitched down from the boiler to
the vent termination. Do not connect other appliances to this
vent.
Vent Pipe Material:
A. UL ListedZ-FlexZ-Vent stainless steelvent pipe from
boiler to vent termination,
-or-
B.
UL ListedHeat-FabSaf-T-Vent stainless steelvent pipe
from boiler to vent termination,
-or-
C. UL ListedFlex-LStaR-34stainless steelvent pipe from
boiler to vent termination,
-or-
D. UL ListedProTech FasNSealstainless steel vent pipe from
boiler to vent termination.
Clearance to Combustible Materials: For stainless steelvent
pipe maintain 6" minimum air space clearance to combustible
materials.
Vent Pipe Size:
A. 2, 3, 4 and 5 section boilers use 3" vent pipe connected
directly to the outlet of the induced draft blower.
B.
6 and 7 section boilers use 4" vent pipe, starting with a 3"
to 4" stainless steelvent pipe transition that is connected
directly to the outlet of the induced draft blower. Do not
use 3" vent pipe on 6 or 7 section boilers.
Vent Pipe Length:
A. For stainless steel vent pipe, the maximum horizontal vent
length is 30feet plus one 90°elbowplus termination fitting.
6,
Vent Termination Fitting: For all vent pipe materials, you may
use either:
A. A 90° elbow pointing down, fitted with a minimum 114"
mesh screen to keep out rodents and birds. The elbow shall
be of the same material and size as vent pipe. The elbow
exit should be at least 6" awayfrom exterior wall as shown
in Figure
10.
B.
-0r-
Tjernlund VH- 1 Series sidewall vent hood. For 2, 3, 4, 5
section boilers use VH- 1-3", For 6, 7 section boilers use
VH-1-4".
7. Vent Pipe Termination Location (Figure 10):
a.
When venting through combustible walls, combustible
clearancesmust be considered. TheVH- 1 Sidewallvent
hood provides both the outside vent termination and a
double wallpipe for passing through a combustible wall
up to 8" thick (VH-1-4") or 9" thick (VH-1-3").The hole
in the wall must be 61_ '' square for 3"vent pipe and 7 1/2"
square for 4" vent pipe, in order to insert the VH- 1 side
wall vent hood. The VH- 1may also be used in noncombus-
tible walls.
B.
If the 90° elbow is the termination fitting of choice,then
the singlewall pipe will be passing through the sidewall.
For combustible walls, a ULlisted thimble shall be used
where the single wallpipe passes through the wall. For
combustible walls using Z-Vent, Saf-T-Vent,or StaR-34
vent pipe, use the following:
• 3" vent pipe - use Simpson's Duravent 3" thimble
•4" vent pipe - use Simpson's Duravent 4" thimble. Maxi-
mum wall thickness with this thimble is 7 inches.
B.
C.
Minimum horizontal vent length for all vent materials is 2
feet plus one 90° elbowplus termination fitting.
For additional elbowsreduce the maximum vent length as
shown:
•3" - 90° elbow - reduce vent length 3 feet per each 3" elbow
•4" - 90° elbow - reduce vent length 6 feet per each 4" elbow
For combustible wallsusing ProTech FasNSealwhere the singlewall
vent pipe must pass through the side wall, a UL ListedFasNSealwall
thimble shall be used.
The thimble is adjustable for differentwall thickness, with a maxi-
mum wallthickness of 7 inches. Sealthe thimble along the outside
edge of the plate with caulk or siliconeand fasten to the wall with
screwsor nails.
Example: 6 section boiler has 3 elbows plus the termination fitting.
This means 2 additional 4" elbows will be used, at 6 feet per elbow.
This is equivalent to 12 feet of pipe (2 x 6 =12), therefore maximum
vent length is now 18 feet (30 -12 =18).
C. For single wallpipe through non-combustible walls, the
hole through the wallneed only be large enough to main-
tain the pitch of the vent pipe, and provide proper seal-
ing. A thimble is not required for single wall pipe passing
through noncombustible walls.
D. Theventing system shall terminate at least 3 feet above