Vermont Casting 647 BFC - Manual (Page 5)

5
BFC36 Balance Flue Heat-Circulating Fireplace
7412647
D
Rise
B
G
H
B
Offset
C
E
6 FT.
G
H
A
Hearth
Floor
Chimney
Section
CHIMNEY FLUE EXIT
Elbow
FP269
MBUF
5/16/96
rev. 5/25
TCS8A
Support
Example 1 Example 2 Example 3
Chimney Requirements - Offset Installations
Notes: G + H cannot exceed 20 feet.
Air Space Clearances: = 2” Min. to Combustibles
Illustration Key
The following safety rules apply to
offset installations (letters correspond
with illustration above):
A. Height of the chimney is measured
from the hearth to the chimney exit.
BFC36
Maximum: 50’0”
Minimum:
Without Elbows
14’6”
With 2 Elbows* 14’6”
With 4 Elbows* 21’0”
B. Do not use more than 4 elbows per
chimney.
Attach the straps of the return (top)
elbow to a structural framing member.
The offset (first) elbow of any pair does
not have straps.
FP269
C. The chimney cannot be more than 30˚
(45˚ in Canada) from the vertical plane in
any installation*.
D. The maximum length of the angled run
of the total chimney system is 20 feet. (G
plus H cannot exceed 20 feet.)
E. A chimney support (Model TCS8A)
is required every 6 feet of angled run of
chimney. Chimney supports are required
for every 30 feet and 60 feet of vertical
chimney height above the hearth.
Determine the offset distance of your
chimney arrangement from the centerline
of the fireplace to the centerline of the
chimney where it is to pass through the
first ceiling.
NOTE: This offset distance may not be
your full offset distance. See Examples 2
and 3.
Fig. 3 Chimney system requirements.
IWF282
0 0 0 0 0 3” 11”
1 0 0 0 0 8¹⁄₄" 20"
0 1 0 0 0 11¹⁄₄" 25¹⁄₄"
2 0 0 0 0 13¹⁄₂" 29¹⁄₄"
1 1 0 0 0 16¹⁄₂" 34¹⁄₄"
0 0 1 0 0 20¹⁄₄" 40³⁄₄"
2 1 0 0 0 21³⁄₄" 43¹⁄₂"
0 0 0 1 0 26¹⁄₄" 51¹⁄₄"
0 1 1 0 0 28¹⁄₂" 55¹⁄₄"
1 0 0 1 0 31¹⁄₂" 60¹⁄₄”
0 1 0 1 0 34¹⁄₂" 65¹⁄₂"
0 0 2 0 0 37¹⁄₂" 70³⁄₄"
1 1 0 1 1 41¹⁄₂" 77³⁄₄"
0 0 1 1 1
45" 83³⁄₄"
0 1 2 0 1 47¹⁄₄" 87¹⁄₂"
0 0 0 2 1
51" 94"
0 1 1 1 1 53¹⁄₄" 98"
0 0 3 0 1 56¹⁄₄" 103¹⁄₄"
0 1 0 2 1 59¹⁄₄" 108¹⁄₂"
0 0 2 1 1 62¹⁄₄" 113¹⁄₂"
0 1 3 0 1 64¹⁄₂" 117¹⁄₂"
0 0 1 2 1 68¹⁄₄"
124"
0 1 2 1 1 70¹⁄₂" 128"
0 0 0 3 1 74¹⁄₄" 134¹⁄₂"
0 1 1 2 2
78" 140³⁄₄"
0 0 3 1 2 81" 146"
0 1 0 3 2 84" 151¹⁄₄"
0 0 2 2 2 87" 156¹⁄₂"
0 1 3 1 2 89¹⁄₄" 160¹⁄₄"
0 0 1 3 2
93" 166³⁄₄"
0 1 2 2 2 95¹⁄₄" 170³⁄₄"
0 0 0 4 2 99¹⁄₄" 177³⁄₄"
0 1 1 3 2 101¹⁄₄" 181³⁄₄"
0 0 3 2 2 104¹⁄₄" 186¹⁄₄"
0 1 0 4 2 107¹⁄₄" 191¹⁄₂"
0 0 2 3 2 110¹⁄₄" 196³⁄₄"
0 1 3 2 3 114" 203¹⁄₄"
0 0 1 4 3 117³⁄₄" 209³⁄₄"
0 1 2 3 3 120" 213¹⁄₂"
0 0 0 5 3 123³⁄₄"
220"
30˚ Elbow Offsets
1’ 1¹⁄₂' 3’ 4’
Chimney Support
Offset Rise
FP282
MBUF
5/26/96
OFFSET
RISE
30°
Return
Elbow
30°
Return
Elbow
30°
Offset
Elbow
30°
Offset
Elbow