Marshal MB42 Installation & Operating Manual page 8

DIRECT CONNECTION METHOD (continued)
WARNING:
It is essential that the direct flue be installed as follows. Incorrect
installation will result in unsatisfactory baking, oven damage, and pilot outages.
The flue must be class B or better. The height of the flue should rise 6-8 ft (2-2.5 m) above the
roof of the building or any proximate structure. The flue should be capped with a UL Listed
type vent cap to isolate the unit from external environmental conditions.
The direct vent cannot replace air consumed and vented by the oven. Provisions must be made
to supply the room with sufficient make-up air. Total make-up air requirements for each oven
section should be approximately 30 CFM per section. To increase the supply air entering the
room, a ventilation expert should be consulted.
INSTALLING THE DRAFT HOOD
Ovens ordered for direct venting are supplied with a draft hood. Install the draft hood as
follows:
1. Place the draft hood over the flue connector.
2. Install the rest of the venting system to the draft hood (draft diverter).
CANOPY METHOD
STAINLESS STEEL VENT
(INCLUDED)
DIRECT CONNECTION
METHOD
INSULATED
FLUE VENT
6" Flue
DRAFT DIVERTER
6