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:
WARNING
Fire Risk
•Draft will be restricted if offsets/returns greater than 30° are used.
•Measure how far the chimney needs to be shifted to enable it to avoid the overhead obstacle. See Figure 5.1. Use dimension “A” to determine chimney section required to achieve the needed shift.
•After determining the offset dimension, refer to Table 5.2 and find 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 find the number of chimney sections required and the model number of those particular chimney parts.
•Whenever the chimney penetrates a floor/ceiling, a ceiling firestop must be installed.
•The effective height of the fireplace assembly is measured from the base of the fireplace to the top of the starter collar. See Dimensions in Section 12.
Table 5.2
| A |
| B | SL1106 | SL1112 | SL1118 | SL1136 | SL1148 | ||
in. |
| mm | in. |
| mm | SL406 | SL412 | SL418 | SL436 | SL448 |
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 | 47 |
| 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
A 
B
OVERLAP
Figure 5.1 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 fit your application are two SL1112s or SL412s.
Outdoor Lifestyles by Hearth & Home Technologies Inc. • Montana | 15 |