Installation
900683-01F, 10/2018
Innovative Hearth Products
DRT3500 Series Direct-Vent Gas Fireplaces
33
Table 20 - Venting Components Required for Various Exterior Wall Thicknesses, when using Typical Termination Kits
Vent Components Required
Exterior Wall Thickness
Termination Kit Only
6 to 9-1/4” (152 to 235 mm)
Termination Kit and 6” Vent Section (SV4.5L6)
10-3/4 to 14” (273 to 356 mm)
Termination Kit and 12” Vent Section (SV4.5L12)
16-3/4 to 20” (426 to 508 mm)
Termination Kit and Telescopic Section (SV4.5LA)
and 6” vent section (SV4.5L6)
11-3/4 to 20” (299 to 508 mm)
Horizontal Vent Figures/Tables
NOTE: Secure Vent
®
rigid vent pipe and terminal are shown in the figures. Secure Flex
®
flexible vent pipe and
terminal may also be used.
NOTE: Two (2) 45° elbows may be used in place of one (1) 90° elbow. The same rise to run ratios, as shown in the
venting figures for 90° elbows, must be followed if 45° elbows are used.
NOTE: Maintain the horizontal/inclined run in a straight (no dips), slightly elevated plane. The recommended incline
is approximately 1/4” per 1 ft (20 mm per 1 m) horizontal, in a direction away from the fireplace. Smaller rise per
foot run ratios are acceptable all the way to at or near level. Use a carpenter’s level to measure from a constant
surface and adjust the support straps as necessary.
NOTE: SV4.5VF (Secure Vent), SF4.5VF (Secure Flex) firestop/spacer must be used any time vent pipe passes
through a combustible floor or ceiling. SV4.5HF (Secure Vent), SF4.5HF (Secure Flex) firestop/spacer must be used
any time vent pipe passes through a combustible wall.
WARNING
Do not join separate sections of concentric flexible vent together.
Table 21 - Rear Vent—No Elbows
See Table 20 as an aid in venting component selection for a
particular range of exterior wall thicknesses.
NOTE: “H” is horizontal distance from rear of unit to outer wall
surface
NOTE: Use base vent restrictor with breakaway portion
raised with rear horizontal and slip only on the 35” model
when rear venting with only a slip collar and a termination.
H
H = 28 in. (711 mm) Maximum
**When using Secure Flex, use
Wall Firestop/Spacer SF4.5HF.
When using Secure Flex
®
, use
wall firestop/spacer SF4.5HF, and
install venting with a minimum of
12” rise. (Page 47).
H = 21” (533 mm) maximum
27-1/2”
(699 mm) to outside
of termination
Table 22 - Top Vent—One 90° Elbow, Elbow Connection at Fireplace
H Maximum
V Minimum
feet
meters
feet
meters
3
0.91
Elbow only
Install the U-shaped vent restrictor in any vent run with more
than 4 ft of vertical rise. See Page 22 for more information.
See Table 20 as an aid in venting component selection for a particular
range of exterior wall thicknesses.
NOTE: Only in top vent where elbow is connected at fireplace collar is
it allowed to count elbow as 1 ft. vertical (V) rise.
Wall
firestop/
spacer
SV4.5HF *
When using Secure Flex
®
, use
wall firestop/spacer SF4.5HF.
*
H
V
