Brant Radiant Heaters DX2 Series Manual page 33

DX2 Series
Common Venting (Category I)
The common vent system and all attached appliances must be Category I and must be on the same
control device.
The vent connector should be routed in the most direct route from the units to the common vent.
Where two or more vent connectors enter a common gas vent or chimney flue, the smaller connector shall
enter at the highest level consistent with the available head room or clearance to combustible material.
Restrictions within the common vent such as elbows should be minimized. Each elbow installed within the
common portion of the vent carrying system reduces the maximum common vent capacity by 10%. Refer
to NFPA 54 IFEC tables 13.2(a) through 13.2(e) for capacity.
The vent connector capacities allow for the use of two 90° directional changes. For each additional
required elbow, the vent connector capacity is reduced by 10%.
The common vent cross sectional area must be equal to or greater than the largest vent connector cross
sectional area.
Figure 3.23 • Common Rooftop Venting - Side View
Double-Wall B Vent
Firestop Spacer
**Consult the NFPA ANSI Z223.1 Gas Vent Termination criteria if roof pitch exceeds 9:12.
Rooftop Vent Cap
6" Single-Wall
Vent Pipe
Heater
Dual Exhaust Assembly
3.0 Installation
24 in.
Min.**
Single-Wall Vent Pipe
33
• Common Venting (Category I)
Roof
Use Attic Insulation Shield
(Field Supplied)
Heater