Using Offsets/Returns - Heatilator ST42A Owner's Manual

B. Using Offsets/Returns
To bypass any overhead obstructions, the chimney may be
offset using a 30-deg (SL1130) 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 offset/returns
greater than 30° are used.
Table 5.2
A B
in. mm in.
3-7/8 98 14-1/2
6-1/4 159 18-5/8
9-1/4 235 23-3/4
12-1/4 311 29
14-5/8 371 33
17-5/8 448 38-1/4
21-1/4 540 44-5/8 1133
23-5/8 600 48-3/4 1238
27-1/4 692 55-3/4 1416
29-5/8 752 59 1499
32-5/8 829 64-1/4 1632
35-5/8 905 69-1/2 1765
38 965 73-5/8 1870
41 1041 78-3/4 2000
44-5/8 1133 85 2159
47 1194 89-1/8 2264
50-5/8 1286 95-1/2 2426
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.
mm SL1106 SL1112 SL1118 SL1136 SL1148
368 - - -
473 1 - -
578 - 1 -
737 - - 1
838 - 2 -
972 - 1 1
- - -
1 - -
- - -
1 - -
- 1 -
- - 1
- 2 -
- 1 1
- - -
1 - -
- - -
Heatilator • ST42A • 35038 Rev G • 02/05
• 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 fi 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 fi nd the number of chimney
sections required and the model number of those particular
chimney parts.
• Whenever the chimney penetrates a fl oor/ceiling, a fi restop
spacer must be installed.
• The effective height of the fi replace assembly is measured
from the base of the fi replace to the top of the starter collar.
See Dimensions in Section 12.
- -
- -
- -
- -
- -
- -
1 -
1 -
- 1
Figure 5.3
- 1
Example: Your "A" dimension from Figure 5.3
- 1
is 14-1/2 in. (368 mm). Using Table 5.2 the
- 1
dimension closest to, but not less than 14-1/2
- 1
in. (368 mm) is 14-5/8 in. (371 mm) using a 30°
- 1
offset/return. It is then determined from the table
1 1
that you would need 33 in. (838 mm) (Dimension
1 1
"B") between the offset and return. The chimney
- 2
components that best fi t your application are two
SL1112s.
A
B
1-1/4 in. (32 mm)
OVERLAP
Chimney Offset/Return
17