26
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)
V
H2
H1
H
Table J
H
+ H
1
+ H
2
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 + H2 = 40 feet (12.2 m) Max
H = 8 feet (2.438 meters) Max.
H + H1+ H2 = 20 feet (6.096 meters) Max.
Example:
If 20 feet total (H+H
1
+H
2
)
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 horizontal run
up to a maximum total (H+H
1
+H
2
)
horizontal run of 20 feet.
Table K
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
H
H1
V1
v
Wall Firestop / Spacer
(SV4.5HF)
u
Ceiling Firestop /
Spacer (SV4.5VF)
u
Ceiling Firestop /
Spacer (SV4.5VF)
v
Wall Firestop
/ Spacer (SV4.5HF)
v
Wall Firestop / Spacer
(SV4.5HF)
Figure 41
- Side Vent, THREE 90 DEGREE ELBOWS
Square termination (SV4.5HT-2) shown
Square termination
(SV4.5HT-2) shown.
Figure 42
-
Top Vent, THREE 90 DEGREE ELBOWS
u
When using Secure Flex
®
, use
Firestop / Spacer SF4.5VF
v
When using Secure Flex, use
Firestop / Spacer SF4.5HF
NOTE:
See
Table 8
as an aid in
venting component selection for
a particular range of exterior wall
thicknesses.
u
When using Secure Flex,
use Firestop / Spacer
SF4.5VF
v
When using Secure Flex,
use Firestop / Spacer
SF4.5HF
NOTE:
See
Table 8
as an aid
in venting component selec-
tion for a particular range of
exterior wall thicknesses.
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 horizontal run of 20 feet.
An elbow is acceptable as 1 foot of verti-
cal rise except where an elbow is the only
vertical component in the system. See
Figure 38
.
