Rheem RRNA-B SERIES - Page 12

12
FIGURE 10
EXCEPTION TO NON-COMBUSTIBLE FLOORING REQUIREMENT
I458
BOTH ENDS
MUST BE
OPEN FOR
DOWNFLOW
OR SIDEFLOW
DUCTWORK
TO PROVIDE
VENTILATION
COMBUSTIBLE
STRUCTURE
1” MIN.
NOMINAL
4 x 4 TIMBER
(SIDES ONLY)
SIDEFLOW
SUPPLY
PLENUM
CONNECTION
SUPPLY
PLENUM
(DOWNFLOW)
RETURN PLENUM
(DOWNFLOW)
SIDEFLOW
RETURN PLENUM
CONNECTION
3-1/2” MIN.