26
Table 8.2
B. Using Offsets/Returns
• Use an offset/return to bypass overhead obstructions.
• An offset and return can be used as a single entity or separated by chimney section(s).
WARNING! Risk of Fire! DO NOT use offset/returns greater than 30°. Chimney draft will be restricted and could cause
overheating and fire.
• Measure the shift needed to avoid the overhead obstruction. Refer to dimension A in Figure 8.3.
• Find the appropriate A dimension listed in Table 8.2.
• The B dimension coinciding with the A dimension measurement in Table 8.2 represents the required vertical clearance
needed to complete the offset/return.
• Read across the chart to find the number of chimney sections/model numbers needed between the offset and return.
A
B
1-1/4 in. (32 mm)
OVERLAP
Figure 8.3 Chimney Offset/Return
Heat & Glo • HST-42D • 27177 • Rev AF • 1/11
15-degree
SL306 SL312 SL318 SL324 SL336 SL348
30-degree
A
Offset
B
Height
A
Offset
B
Height
in.
mm
in.
mm
in.
mm
in.
mm
1-5/8
41
13-3/8
340
-
-
-
-
-
-
3-5/8
92
15-1/2
394
2-7/8
73
17-3/4
451
1
-
-
-
-
-
5-1/2
140
18-5/8
473
4-1/8
102
22-3/8
568
2
-
-
-
-
-
7-1/4
184
21-3/4
552
4-1/2
114
23-5/8
600
-
1
-
-
-
-
8-1/2
216
23-3/4
603
5-3/4
146
28-1/4
718
1
1
-
-
-
-
10-1/4
260
27
686
6
152
29-3/8
746
-
-
1
-
-
-
11-1/2
292
29
737
7-1/4
184
34
864
-
2
-
-
-
-
13-1/4
337
32-1/8
816
7-3/4
197
36-1/8
918
-
-
-
1
-
-
14-1/2
368
34-1/8
867
8-3/4
222
39-3/4
1010
1
-
-
1
-
-
16-1/4
413
37-3/8
949
10-3/8
264
45-5/8
1159
-
-
2
-
-
-
19-1/4
489
42-1/2
1080
10-5/8
270
46-3/4
1187
-
-
-
-
1
-
20-1/2
521
44-5/8
1133
11-7/8
302
51-3/8
1305
1
-
-
-
1
-
22-1/4
565
47-3/4
1213
13-1/2
243
57-1/4
1454
-
-
-
2
-
-
25-1/4
641
52-7/8
1343
13-3/4
349
58-3/8
1483
-
-
-
-
-
1
26-1/2
673
55
1397
15
381
63
1600
1
-
-
-
-
1
28-1/4
718
58-1/8
1476
16-1/2
419
68-3/4
1746
-
1
-
-
-
1
31-1/4
794
63-1/4
1607
18
457
74-5/8
1895
-
-
1
-
-
1
34-1/4
870
68-1/2
1740
19-5/8
498
80-3/8
2042
-
-
-
1
-
1
37-1/4
946
73-3/4
1873
20-5/8
524
84-1/8
2137
1
-
-
1
-
1
39-1/8
994
76-7/8
1953
22-3/4
578
91-7/8
2334
-
-
-
-
1
1
43-1/4
1099
84-1/8
2137
24
610
96-1/2
2451
1
-
-
-
1
1
45-1/8
1146
87-1/4
2216
25-7/8
657
103-1/2 2629
-
-
-
-
-
2
49-1/4
1251
94-1/2
2400
Proper assembly of air-cooled chimney parts result in an overlap at chimney joints of 1-1/4 in. (32 mm). Effective length is built
into this chart.
Example:
Your “A” dimension from Figure 8.3 is 14 1/2 in. (368
mm). Using Table 8.2 the dimension closest to, but
not less than 14 1/2 in. (368 mm) is 14 1/2 in. (368
mm) using a 30° offset/return.
You determine from the table that you need 34 1/8 in.
(867 mm) (Dimension “B”) between the offset and
return.
The chimney component that best fits your applica-
tion is one SL324.
