25
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Installation and Operation Instructions
900300-00, 01/2018
Innovative Hearth Products
DRT35ST and DRT35PF Direct-Vent Gas Fireplaces
HORIZONTAL VENT FIGURES/TABLES (continued)
H1
V
H
V
H
H1
u
When using Secure Flex, use Firestop
/ Spacer SF4.5VF
v
When using Secure Flex, use Firestop
/ Spacer SF4.5HF
u
When using Secure Flex
®
, use Firestop /
Spacer SF4.5VF
v
When using Secure Flex, use Firestop /
Spacer SF4.5HF
u
Ceiling Firestop
/ Spacer (SV4.5VF)
v
Wall Firestop/
Spacer (SV4.5HF)
u
Ceiling Firestop
/ Spacer (SV4.5VF)
v
Wall Firestop/
Spacer (SV4.5HF)
v
Wall Firestop/
Spacer (SV4.5HF)
Table G
H+H
1
Maximum
H
Maximum
V Minimum
feet
(meter)
feet
(meter)
feet
(meter)
5
(1.524)
2
(0.610)
1
(0.305)
10
(3.048)
4
(1.219)
2
(0.610)
15
(4.572)
6
(1.829)
3
(0.914)
20
(6.096)
8
(2.438)
4
(1.219)
V + H + H1 = 40 feet (12.2 m) Max
H = 8 feet (2.438 meters) Max.
H + H1 = 20 feet (6.096 meters) Max.
Example:
If 20 feet of (H + H
1
) horizontal vent
run is needed, then 4 feet minimum of (V) vertical
vent will be required.
This table shows a 1(V) to 5(H) ratio. For every 1
foot of (V) vertical, you are allowed 5 feet of (H+
H
1
) horizontal run, up to a maximum horizontal
run of 20 feet.
Table H
H
+ H
1
Maximum
V Minimum
feet
(meter)
feet
(meter)
3
(0.914)
Elbow Only
5
(1.524)
1
(0.305)
10
(3.048)
2
(0.610)
15
(4.572)
3
(0.914)
20
(6.096)
4
(1.219)
V +
H
+ H
1
= 40 feet (12.2 m) Max.
H
+ H
1
= 20 ft. (6.096 m) Max.
Figure 39
-
Side Vent, TWO 90 DEGREE ELBOWS
Figure 40
-
Top Vent, TWO 90 DEGREE ELBOWS
Square termination
(SV4.5HT-2) shown
Square termination
(SV4.5HT-2) shown
See Table 8 on Page 24 as an aid in venting
component selection for a particular range of
exterior wall thicknesses.
See Table 8 on Page 24 as an aid in venting
component selection for a particular range
of exterior wall thicknesses.
Example:
If 20 feet of (H + H
1
) horizontal vent run
is needed, then 4 feet minimum of (V) vertical vent
will be required.
This table shows a 1(V) to 5(H) ratio. For every 1
foot of (V) vertical, you are allowed 5 feet of (H+
H
1
) horizontal run, up to a maximum horizontal
run of 20 feet.
An elbow is acceptable as 1 foot of vertical rise except
where an elbow is the only vertical component in
the system. See
Figure 38
.
