Installation
900683-01F, 10/2018
Innovative Hearth Products
DRT3500 Series Direct-Vent Gas Fireplaces
22
9.
Install the Vent Restrictor (if necessary)
1. Use the vent run descriptions in Figure 11 to determine if a vent restrictor is necessary.
2. If necessary, assemble the vent restrictor and wing as detailed in Figures 11 and 14.
3. If necessary, install the appropriate vent restrictor (Figure 12 or 13).
NOTE: If installing the vent restrictor in a rear vent application, ensure the factory-installed intake air baffle is in place (Figure 13).
NOTE: The vent restrictor is shipped in the firebox.
Figure 11 - When to use a vent restrictor
2 1/2”
Break-Away
1
3
20
40
6
10
40
25 ft Maximum
horizontal run (flat to near level)
60 ft Maximum vertical run
60
1.9
25
Horizontal Distance (ft)
Vertical Height (ft) from top of unit
Vertical Height (ft)
2
5
Elbow**
5
10
15
3” Base + wing
3” Base
6 ft Minimum
vertical run
6 ft Minimum vertical ru
n
None
*
*
* For straight runs or runs with elbows as illustrated in Vertical Vent Figures/Tables starting on
Page 28
** No rise required.
*** NOTE: In 35” Models, when venting Rear Horizontal with slip collar and termination only,
install base vent restrictor with the breakaway portion raised
Vent Restrictor with Vertical Terminations
When vertically terminating the vent system through the roof and using the vent restrictor, install the vent restrictor
in the top vent of the fireplace outlet.
If installing more than 6 ft of vertical venting, install the restrictor (Figure 12), from inside or outside the unit, in the
inner fireplace collar. The vent restrictor is held in place by friction.
Vent Restrictor with Horizontal Terminations
When horizontally terminating a vent system with a vertical vent run up to 4 ft through an exterior wall, no vent
restrictor is required.
If installing more than 4 ft of vertical venting, install the restrictor (Figure 13), from inside or outside the unit, in the
inner fireplace collar. The vent restrictor is held in place by friction.
Figure 12 - Vent restrictor installation, Top vent
U-Shaped Vent
Restrictor
Inner
Fireplace
Collar
Appliance Top Vent Outlet
U-SHAPED VENT
RESTRICTOR
APPLIANCE REAR
VENT OUTLET
INNER FIREPLACE
COLLAR
Inner Fireplace Collar
Appliance Rear
Vent Outlet
U-Shaped Vent
Restrictor
Intake Air Baffle
Base Vent Restrictor
Base Vent Rest Wing
With break-away
raised***
Figure 13 - Vent restrictor installation, Rear vent
Figure 14 - Vent restrictor assembly
U-Shaped Vent
Restrictor
Inner
Fireplace
Collar
Appliance Top Vent Outlet
U-SHAPED VENT
RESTRICTOR
APPLIANCE REAR
VENT OUTLET
INNER FIREPLACE
COLLAR
Inner Fireplace Collar
Appliance Rear
Vent Outlet
U-Shaped Vent
Restrictor
Intake Air Baffle
Base Vent Restrictor
Base Vent Rest Wing
With break-away
raised***
Base Vent Restrictor
U-Shaped Vent
Restrictor
Inner
Fireplace
Collar
Appliance Top Vent Outlet
U-SHAPED VENT
RESTRICTOR
APPLIANCE REAR
VENT OUTLET
INNER FIREPLACE
COLLAR
Inner Fireplace Collar
Appliance Rear
Vent Outlet
U-Shaped Vent
Restrictor
Intake Air Baffle
Base Vent Restrictor
Base Vent Rest Wing
With break-away
raised***
Base Vent Rest Wing
With break-away
raised***
Inner Fireplace Collar
Appliance Rear
Vent Outlet
U-Shaped Vent
Restrictor
Intake Air Baffle
