18
Heatilator • Birmingham BIR50-B Installation Manual • 4059-701 • Rev G • 06/29/15
G. Assemble Chimney Sections
• Attach the first chimney section or offset onto
the top of the fireplace (Figure 4.3). Sheet metal
screws are required to connect chimney section
to the fireplace starter collar. Continue to add
additional sections of chimney as needed.
• Use a wall strap every eight feet of chimney
height.
• For each additional chimney section use four
of the sheet metal screws provided to make a
secure connection between the chimney sections
(Figure 4.4). Do not penetrate the inner liner of
the chimney.
Figure 4.3
Figure 4.4
H. 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 ft. Chimney draft will be restricted and could cause overheating
and fire.
• Measure the shift required to avoid the overhead obstruction
(Offset, Figure 4.5).
• Find the appropriate offset dimension listed in Table 4.2.
• The rise (see Figure 4.5) coinciding with the offset dimension
measurement in Table 4.2 represents the required vertical
clearance needed to complete the offset/return.
Table 8.2
Elbow
Angle
from
Vertical
Chimney
Length
Between
Elbows
Offset
Inches
Rise
Inches
Offset
Millimeters
Rise
Millimeters
15°
0
2 5/8
21 5/8
67
549
15°
12 in./
305 mm
5 1/2
32 1/4
140
819
15°
18 in./
457 mm
7 1/8
38
181
965
15°
36 in./
914 mm
11 3/4
55 3/8
298
1407
15°
48 in./
1219 mm
14 7/8
67
378
1702
30°
0
6 1/4
24 1/2
159
622
30°
12 in./
305 mm
11 3/4
34
298
864
30°
18 in./
457 mm
14 3/4
39 1/4
375
997
30°
36 in./
914 mm
23 3/4
54 7/8
603
1394
30°
48 in./
1219 mm
29 3/4
65 1/4
756
1657
RISE
OFFSET
Figure 4.5
