Heatilator • CI60 • 4013-031 Rev M • 10/06
18
B. Using Offsets/Returns
To bypass any overhead obstructions, the chimney may be
offset using an offset/return.
An offset and return may be attached together or a chimney
section(s) may be used between an offset and return.
Perform the following steps to determine the correct chim-
ney component combination for your particular installation:
•
Measure how far the chimney needs to be shifted to enable
it to avoid the overhead obstacle. See Figure 5.3. Use
dimension “A” to determine chimney section required to
achieve the needed shift.
• After determining the offset dimension, refer to Table 5.2
and
¿
nd the “A” dimension closest to but not less than the
distance of shift needed for your installation.
• The “B” dimension that coincides with the “A” dimension
represents the required vertical clearance that is needed
to complete the offset and return.
• Read across the chart and
¿
nd the number of chimney
sections required and the model number of those particular
chimney parts.
•
Whenever the chimney penetrates a
À
oor/ceiling, a ceiling
¿
restop must be installed.
•
The effective height of the
¿
replace assembly is measured
from the base of the
¿
replace to the top of the starter collar.
See Dimensions in Section 12.
Table 5.2
A
B
1-1/4 in. (32 mm)
OVERLAP
Figure 5.3
Chimney Offset/Return
Example:
Your “A” dimension from
Figure 5.3 is 14 1/2 in. (368 mm). Using
Table 5.2 the dimension closest to, but
not less than 14 1/2 in. (368 mm) is
15 3/4 in. (400 mm) using a 30° offset/
return. It is then determined from the
table that you would need 36 5/8 in.
(930 mm) (Dimension “B”) between
the offset and return. The chimney
components that best
¿
t your application
are two SL412s.
Fire Risk
• Draft will be restricted if offset/returns
greater than 30° are used.
WARNING
A
B
SL406
SL412
SL418
SL436
SL448
in.
mm
in.
mm
4 7/8
124
17 7/8
454
-
-
-
-
-
7 1/4
184
2 2
559
1
-
-
-
-
9 3/4
248
26 1/8
664
2
-
-
-
-
10 1/4
260
27 1/4
692
-
1
-
-
-
12 3/4
324
31 3/8
797
1
1
-
-
-
13 1/4
337
32 3/8
822
-
-
1
-
-
15 3/4
400
36 5/8
930
-
2
-
-
-
18 1/8
460
40 3/4
1035
1
2
-
-
-
18 3/4
476
41 3/4
1060
-
1
1
-
-
21 3/4
552
4 7
1194
-
-
2
-
-
22 1/4
565
48
1219
-
-
-
1
-
24 3/4
629
52 1/8
1324
1
-
-
1
-
27 3/4
705
57 3/8
1457
-
1
-
1
-
28 1/4
718
58 3/8
1483
-
-
-
-
1
30 3/4
781
62 1/2
1588
1
-
-
-
1
33 3/4
857
67 3/4
1721
-
1
-
-
1
36 3/4
933
73
1854
-
-
1
-
1
39 3/4
1010
78 1/8
1984
-
-
-
2
-
41 1/8
1045
82 3/8
2092
1
-
-
2
-
45 3/4
1162
88 1/2
2248
-
-
-
1
1
48 1/8
1222
92 3/4
2356
1
-
-
1
1
51 3/4
1314
98 7/8
2511
-
-
-
-
2
Proper assembly of air cooled chimney parts results in an overlap of chimney joints
of 1-1/4 in. (32 mm). Effective length is built into this table.
¨
