Rheem RGPE series Installation Instructions Manual page 14

FIGURE 9
COMBUSTION AIR FITTING – NON-ATTIC COMBUSTION AIR PULL, RGPE ONLY
6" MIN.
GROUND OR
SHELF SURFACE
NOTE: PREDRILL HOLES FOR SCREWS TO PREVENT CRACKING.
B: Method 1
Provide two permanent openings,
one located within 12 inches of the
top and one located within 12 inches
of the bottom of the enclosure. Each
opening shall communicate directly,
or by ducts, with the outdoors or
spaces (crawl or attic) that freely
communicate with the outdoors.
a. Where directly communicating
with the outdoors or where com-
municating to the outdoors
through VERTICAL DUCTS, each
opening shall have a minimum
free area of 1 square inch for
each 4000 BTUH of total appli-
ance input rating in the enclosure.
Here are typical duct sizes:
VERTICAL OUTDOOR AIR
OPENING DIMENSIONS
BTUH Free Area
Input Each Opening
50,000 12.50 sq. inches
75,000 18.75 sq. inches
100,000 25.00 sq. inches
125,000 31.25 sq. inches
14
ATTACH OPTIONAL DOUBLE ELBOW TO TOP INLET AIR
OPENING TO PREVENT ACCIDENTAL BLOCKAGE OF
INTAKE OPENING. THIS IS NOT A REQUIREMENT. (SEE
PREVIOUS PAGE.) SINGLE ELBOW IS ALLOWED BUT
MAY NOT PREVENT DEBRIS FROM BEING DROPPED
INTO THE FURNACE.
PVC
DOUBLE
ELBOW
6" MININUM
CLEARANCE
#8 SCREWS
b. Where communicating with out-
doors through HORIZONTAL
DUCTS, each opening shall have
a minimum free area of 1 square
inch for each 2000 BTUH of total
input rating for all equipment in
the enclosure. Here are typical
duct sizes:
HORIZONTAL OUTDOOR AIR
OPENING DIMENSIONS
BTUH
Input
50,000
75,000
100,000
125,000
B: Method 2
One permanent opening, located within
12 inches of the top of the enclosure,
shall be permitted where the equipment
has clearances of at least 1 inch from
the sides and back and 6 inches from
Round
the front of the appliance. The opening
Pipe Size
shall directly communicate with the out-
4"
doors or communicate through a verti-
5"
cal or horizontal duct to the outdoors or
spaces (crawl or attic) that freely com-
6"
municate with the outdoors and have a
7"
minimum free area of:
EXHAUST
METAL FLUE
PIPE ONLY
#8 SCREWS
Free Area Round
Each Opening Pipe Size
25.00 sq. inches 6"
37.50 sq. inches 7"
50.00 sq. inches 8"
62.50 sq. inches 9"
a. One square inch for each 3000
BTUH of the total input rating of
all equipment located in the
enclosure, AND
b. Not less than the sum of the
areas of all vent connectors in the
confined space.
IMPORTANT: If the furnace is in a
location with an exhaust fan, there
must be sufficient ventilation to pre-
vent the exhaust fan from creating a
negative pressure in the room.
Combustion air openings must NOT
BE RESTRICTED in any manner.
CONSULT LOCAL CODES FOR
SPECIAL REQUIREMENTS.