21
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
VERTICAL VENT FIGURES / TABLES (CONTINUED)
H1
V
V1
H
Table C
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 + V1 + 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 total (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 total horizontal run of 20 feet.
Figure 32
- Side Vent - THREE ELBOWS
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)
u
Ceiling Firestop /
Spacer (SV4.5VF)
v
Wall Firestop/
Spacer (SV4.5HF)
Table D
H +
H
1
Maximum
V Minimum
feet
(meter)
feet
(meter)
5
(1.524)
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)
H + H
1
= 20 feet (6.096 m) Max.
V + V
1
+ H + H
1
= 40 ft. (12.192 m) Max.
V
H1
H
V1
u
Ceiling
Firestop / Spacer
(SV4.5VF)
v
Wall Firestop/
Spacer (SV4.5HF)
Example:
If 20 feet total (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 total 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
.
Figure 33-
Top Vent - THREE ELBOWS
u
When using Secure Flex, use Firestop / Spacer SF4.5VF
v
When using Secure Flex, use Firestop / Spacer SF4.5HF
