Vermont Casting DVRT41 - Manual (Page 16)

16
DVRT41 Direct Vent Gas Fireplace
10006740
In Figure 28 & 29, dimension A plus B must not be
greater than 17’ (5.2m)
• The maximum number of 45
°
elbows permitted per
side wall installation is two (2). These elbows can
be installed in either the vertical or horizontal run.
• For each 45
°
elbow installed in the horizontal run,
the length of the horizontal run MUST be reduced
by 18” (457mm). This does not apply if the 45
°
elbows are installed on the vertical part of the vent
system.
• The maximum number of elbow degrees in a sys-
tem is 270
°
. (Fig. 30)
Example:
Elbow 1 = 90
°
Elbow 2 = 45
°
Elbow 3 = 45
°
Elbow 4 = 90
°
Total angular variation = 270
°
1
2
3
4
1
2
3
4
1 + 2 + 3 + 4 = 270
°
FP1180
Fig. 30 Maximum elbow usage.
• The maximum number of 90
°
elbows per side wall
installation is three (3). (Fig. 2)
• If a 90
°
elbow is fitted directly on top of the fireplace
flange the maximum horizontal vent run before the
termination or a vertical rise is 36” (914mm). (Fig.
27)
3 x 90
°
Elbows
3 x 90
°
Elbows
FP1176
Fig. 26 Maximum three (3) 90
°
elbows per installation.
7’6"
(2.3m)
A B
A + B = 17’ (Max.)
(5.2m)
FP1178
Fig. 28 Horizontal run reduction.
36"
(914mm)
Max.
36"
(914mm)
Max.
FP1177
Fig. 27 Maximum horizontal run with no rise.
A + B = 17’
(518cm) Max.
10'
(254 cm)
7'
(178 cm)
Fig. 29 Maximum vent run with elbows.
V584-201
8'
(244 cm)
A B
• If a 90
°
elbow is used in the horizontal vent run
(level height maintained) the horizontal vent length
is reduced by 36” (914mm). (Fig. 28 & 29) This does
not apply if the 90
°
elbows are used to increase or
redirect a vertical rise. (Fig. 26)
Example: According to the vent graph (Page 13) the
maximum horizontal vent length in a system with a 7
¹⁄₂
’
(2.3m) rise is 20’ (6m) and if a 90
°
elbow is required in
the horizontal vent it must be reduced to 17’ (5.2m).