Vermont Casting DVRT43 Gravity Ducting System, Vermont Castings, Majestic Products DVRT36/39/43

Vermont Castings, Majestic Products DVRT36/39/43

Min.

2’ (610 mm)

		FP1189
Fig. 37	Minimum termination to roof clearance.
	(3) #5 Sheet	(3) #5
	Metal Screws	Sheet Metal
	per Joint	Screws per
		Joint
	Sealant	Sealant
	Storm
		Storm
	Collar
		Collar
		TWL101a
Fig. 38	Roof flashing.

Gravity Ducting System

The Gravity Ducting System is only applicable if installing the DVRT43 Direct Vent Fireplace.

Installation of the DVRT43 fireplace provides an opportunity to heat either rooms on an upper level or adjacent rooms on the same level without the use of a blower. However, with the internal blower installed, there will be some increase in warm air movement to rooms serviced by the gravity duct. (Fig. 39 and Fig. 40)

1.Plan the gravity duct run first. Use the following graph (Fig. 39) to ensure that the installation meets the recommendations. There is a maximum number of three (3) elbows in a run, however, the run must never go in a downward direction, as this can trap heat in the gravity vent system. Be aware when designing the ducting system that elbows will restrict airflow. Minimize the use of elbows in any installation.

2.It is recommended that the gravity ducting system be installed so that the grilles exit at the same vertical level. If the gravity venting system is installed so the ducting exits at different levels, a chimney effect may occur, resulting in uneven heat distribution.

Do not discharge directly into a wall or inside an enclosure.

3.Materials needed for the gravity ducting installation:

•(2) 5” dia. duct to grille connector boots

•(2) Wall Outlet grilles

•5” dia. rigid (“C” vent) or 5” dia. flexible metal ducting

•5” dia. elbows (maximum of 3 per run)

4.Remove the gravity duct plugs from the top of the DVRT43 by taking out the two (2) screws around the perimeter of each plug, then removing the plugs from the fireplace.

NOTE: Do not remove the center screw from the plugs.

5.Install 5” rigid (C-Vent) or flexible metal ducting on the DVRT43 and run the ducting, observing the limitations shown in the graph. Be aware that flexible ducting is more restrictive to air flow than rigid ducting.

6.Secure all joints with three (3) sheet metal screws. Seal all joints with foil-faced aluminium tape to prevent heat loss and maintain maximum air flow.

7.Ensure the following clearances are maintained when installing the DVRT43 Gravity Ducting System.

Clearance to Combustibles

Clearance between ducting and combustibles = 1” (25mm)

Clearance between grille adapter and combustibles = 0” (0mm)

Never allow a downward slope in any section of the ducting.

Fireplace	9
of	10
	8
Top
	7
from
	6
Ventof	4
Height	5
	3
Vertical	2
	5	6	7	8	9	10	11	12	13	14	15

Maximum Horizontal Dimensions

NOTE: All dimensions are in FEET.

Conversion factor to metric: 1’ = 305mm

FP1190

Fig. 39 Gravity vent diagram.

10002428 21