Raypak 122-322 Operating And Installation Instructions page 31

SECTION J-2 Horizontal Thru-Wall Venting (Category III)
Fig # 9402
HORIZONTAL THRU-WALL VENTING (CATEGORY III) TABLE
•
Horizontal Thru-wall Venting System (Category III) Installation
These installations utilize the heater-mounted blower to vent the combustion products to the outdoors. Combustion air is
taken from inside the room and the vent is installed horizontally through the wall to the outdoors. Adequate combustion and
ventilation air must be supplied to the mechanical room in accordance with the NFGC or, in Canada, the B149.1 and .2
Installation Code.
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