Offsets/Returns - Heatilator A36C Installation Manual

B. 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. Secure offsets with screws ( not to exceed 1/2" / 13 mm in length) Secure returns with strapping.
Straight chimney sections may be secured with screws. Keep chimney sections from separating or twisting.
• Measure the shift needed to avoid the overhead obstruction. Refer to dimension A in Figure 4.2.
• Find the appropriate A dimension listed in Table 4.3. The B dimension coinciding with the A dimension measurement in
Table 4.3 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.
Figure 4.2 Chimney Offset/Return
Table 4.3 Offset Dimensions
15-degree
A B
in. mm in. mm
1 5/8 41 13 3/8 340
2 7/8 73 17 3/4 451
4 1/8 102 22 3/8 568
4 1/2 114 23 5/8 600
5 3/4 146 28 1/4 718
6 152 29 3/8 746
7 1/4 184 34 864
7 3/4 197 36 1/8 918
8 3/4 222 39 3/4 1010 16 1/4
10 3/8 264 45 5/8 1159 19 1/4
10 5/8 270 46 3/4 1187 20 1/2
11 7/8 302 51 3/8 1305 22 1/4
13 1/2 243 57 1/4 1454 25 1/4
13 3/4 349 58 3/8 1483 26 1/2
15 381 63 1600 28 1/4
16 1/2 419 68 3/4 1746 31 1/4
18 457 74 5/8 1895 34 1/4
19 5/8 498 80 3/8 2042 37 1/4
20 5/8 524 84 1/8 2137 39 1/8
22 3/4 578 91 7/8 2334 43 1/4 1099 84 1/8 2137
24 610 96 1/2 2451 45 1/8 1146 87 1/4 2216
25 7/8 657 103 1/2 2629 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.
Heatilator • A36/42C, A36/42CH • Installers Manual • 4017-262 • Rev D • 10/07/13
16
A
B
1-1/4 in. (32 mm)
OVERLAP
30-degree
A B
in. mm in. mm
3 5/8 92 15 1/2 394
5 1/2 140 18 5/8 473
7 1/4 184 21 3/4 552
8 1/2 216 23 3/4 603
10 1/4 260 27 686
11 1/2 292 29 737
13 1/4 337 32 1/8 816
14 1/2 368 34 1/8 867
413 37 3/8 949
489 42 1/2 1080
521 44 5/8 1133
565 47 3/4 1213
641 52 7/8 1343
673 55 1397
718 58 1/8 1476
794 63 1/4 1607
870 68 1/2 1740
946 73 3/4 1873
994 76 7/8 1953
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) us-
ing a 30° offset/return.
You determine from the table that you need 34 1/8 in.
(867 mm) (Dimension "B") between the offset and re-
turn.
The chimney component that best fits your application is
one SL324.
SL306 SL312 SL318 SL324 SL336 SL348
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1 - - 1
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1 - - -
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1 -
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