Direct Flue Arrangement; Venting Problems - Blodgett 900 Series Installation Manual

VENTILATION

DIRECT FLUE ARRANGEMENT

When the installation of a mechanically driven exhaust hood is impractical the oven may be vented by a direct flue arrange-
ment.
WARNING:
It is essential that the direct flue be installed as follows. Incorrect installation will result in unsatisfactory
baking and oven damage.
The flue must be class B or better with a diameter of 10" (25.4 cm). The height of the flue should rise 6-8 ft (2-2.5 m) above
the roof of the building or any proximate structure. Never direct vent the oven into a hood. 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. See Figure 9.
2. Secure both ends with the sheet metal screws provided.

VENTING PROBLEMS

Blodgett gas deck ovens use the natural principal of heat rising as the basic method of ventilation. If the venting of any deck
oven is either restricted or forced in any way the baking characteristics of the oven will be adversely affected.
Examples of forced venting include:
• installation of a fan in a direct vent pipe
• use of a canopy type hood without the draft diverter
Examples of restricted venting include:
• use of tees and elbows
• long horizontal runs
Insufficient make-up air can cause heated air and combustibles to remain in the oven shortening the life of the components.
DECK OVENS
Draft Hood
Figure 9
10
Flue
Front of Oven
INSTALLATION