Installation
900414-00 12/2015
Innovative Hearth Products
MHD 35/40 Series Direct-Vent Gas Fireplaces
35
Securing screws
in three (3) places
through perforation
and into the pipe
Table 26 - Rear Vent—Three 90° Elbows
H + H
1
+ H
2
Maximum
H Maximum
V Minimum
V
*
When using
Secure Flex
, use
Ceiling Firestop/Spacer
SF4.5VF
.
**
When using
Secure Flex
, use
Wall Firestop/Spacer
SF4.5HF
.
Wall Firestop/Spacer
SV4.5HF**
®
Ceiling
Firestop/Spacer
SV4.5VF*
H
1
H
H
2
When using Secure
Flex
®
, use ceiling
firestop/spacer
SF4.5VF.
When using Secure
Flex, use wall firestop/
spacer SF4.5HF.
*
**
Wall firestop/spacer
SV4.5HF **
Ceiling
firestop/spacer
SV4.5VF *
H
V
H1
H2
feet
meters
feet
meters
feet
meters
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 + H
1
+ H
2
= 60 ft (18.288 m) maximum
H = 8 ft (2.438 m) maximum
H + H
1
+ H
2
= 25 ft (7.62 m) maximum
Install the U-shaped vent restrictor in any vent run with more than 4 ft of
vertical rise. See
Page 21
for more information.
See
Table 20
as an aid in venting component selection for a particular range of
exterior wall thicknesses.
If 20 ft of (H) horizontal vent run is needed, then 4 ft minimum of (V) vertical vent will
be required.
This table shows a 1 (V) to 5 (H) ratio. For every 1 ft of (V) vertical, you are allowed 5
ft of (H) horizontal run, up to a maximum horizontal run of 20 ft (6.096 m).
Table 27 - Top Vent—Three 90° Elbows
H Maximum
V Minimum
*
When using
Secure Flex
, use
Ceiling Firestop/Spacer
SF4.5VF
.
**
When using
Secure Flex
, use
Wall Firestop/Spacer
SF4.5HF
.
Ceiling
Firestop/Spacer
SV4.5VF*
Wall Firestop/Spacer
SV4.5HF**
V
H
V1
Wall Firestop/Spacer
SV4.5HF**
1
H
Wall firestop/spacer
SV4.5HF **
When using Secure Flex
®
, use
ceiling firestop/spacer SF4.5VF.
When using Secure Flex, use wall
firestop/spacer SF4.5HF.
*
**
Wall firestop/spacer
SV4.5HF **
Ceiling
firestop/spacer
SV4.5VF *
H
V
H1
V1
feet
meters
feet
meters
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
= 25 ft (7.62 m) maximum
V + V
1
+ H + H
1
= 60 ft (18.288 m) maximum
Install the U-shaped vent restrictor in any vent run with more than 4 ft of
vertical rise. See
Page 21
for more information.
See
Table 20
as an aid in venting component selection for a particular range of
exterior wall thicknesses.
If 20 ft of (H) horizontal vent run is needed, then 4 ft minimum of (V) vertical vent
will be required.
This table shows a 1 (V) to 5 (H) ratio. For every 1 ft of (V) vertical, you are allowed 5
ft of (H) horizontal run, up to a maximum horizontal run of 20 ft (6.096 m).
