Rheem GF901U Series Installation Instructions Manual page 31

FIGURE 22
STANDARD VERTICAL DIRECT VENTING
UPFLOW MODEL SHOWN (TYPICAL FOR DOWNFLOW MODELS)
EXHAUST
5
TERMINATION
DETAIL A
ROOF LINE
EXHAUST PIPE
COMBUSTION AIR PIPE
NOTES:
1 THE COMBUSTION AIR PIPE MUST
TERMINATE IN THE SAME PRESSURE
ZONE AS THE EXHAUST PIPE.
2 INCREASE THE 12-IN. MINIMUM
4
TO KEEP TERMINAL OPENING
ABOVE ANTICIPATED LEVEL OF
SNOW ACCUMULATION WHERE
APPLICABLE.
3 WHEN 3-IN. DIAM. PIPE IS USED,
REDUCE TO 2-IN. DIAMETER BEFORE
PENETRATING ROOF. A MAXIMUM OF
18 IN. OF 2-IN. PIPE MAY BE USED
BEFORE PASSING THROUGH ROOF.
4 SUPPORT VERTICAL PIPE EVERY 6
FEET.
EXHAUST TERMINATION - TERMINATE
5
THE LAST 12 INCHES WITH 2" PVC PIPE
ON 90,000 AND 120,000 BTUH MODELS.
REDUCE AND TERMINATE THE LAST
12 INCHES WITH 1 1 / " PVC PIPE ON
2
45,000 THROUGH 75,000 BTUH
MODELS. SEE DETAIL A.
6 30" MAXIMUM EXPOSED VENT
LENGTH.
FIGURE 23
STANDARD HORIZONTAL DIRECT VENTING
UPFLOW MODEL SHOWN (TYPICAL FOR DOWNFLOW MODELS)
SUPPLY AIR
EXHAUST PIPE
COMBUSTION AIR PIPE
NOTES:
1 SUPPORT HORIZONTAL PIPE
EVERY FOUR FEET.
2 WHEN 3 IN. PIPE IS USED REDUCE TO 2 IN.
BEFORE PENETRATING OUTSIDE WALL.
3 18 IN. MAXIMUM. 2 IN. DIAMETER PIPE MAY
BE USED INSIDE THE WALL.
4 DETAIL "A" - EXHAUST TERMINATION
TERMINATE THE LAST 12 INCHES WITH 2"
PVC PIPE ON 90,000 AND 120,000 BTUH
MODELS. REDUCE AND TERMINATE THE
LAST 12 INCHES WITH 1 1 / " PVC PIPE ON
2
45,000 THROUGH 75,000 BTUH MODELS.
5 INCREASE THE 12 IN. MINIMUM ABOVE
GRADE TO KEEP TERMINAL OPENINGS
ABOVE ANTICIPATED LEVEL OF SNOW
ACCUMULATION WHERE APPLICABLE.
6 DETAIL "B", INSTALL WIND DEFLECTOR
VANE IN 2 IN. PVC COUPLING IN VERTICAL
POSITION USING PVC SOLVENT.
THE COMBUSTION AIR TERMINATION MUST
BE IN THE SAME PRESSURE ZONE AS THE
EXHAUST TERMINATION.
3" MAX.
SEPARATION
12"
COMBUSTION AIR
PIPE
12" MIN.
30 MAX
SEPARATION
12" MIN. ABOVE
ROOF LEVEL
3
SUPPLY AIR
1
2" OR 3" TEE
W/DRAIN TRAP
6
COMBUSTION AIR TERMINATION
DETAIL B
COMBUSTION
1
AIR PIPE
2
12" MIN.
EXHAUST VENT
RETURN AIR
30 MAX
2
3
12"
4"
12" MIN. ABOVE
GRADE LEVEL
TRAP
SEE DETAIL B
CONNECT
TO DRAIN
RETURN AIR
2" PVC
VANE
COUPLING
EXHAUST
MAX.
VENT
12"
MIN.
3"
EXHAUST
MAX.
VENT
12"
MIN.
ROOF LINE
5
5
PITCHED ROOF INSTALLATIONS
12"
4
EXHAUST TERMINATION
DETAIL A
SEE DETAIL A
4"
5
3"
EXHAUST
4"
INTAKE
DETAIL C
EXHAUST / INTAKE RELATIONSHIP
3"
COMBUSTION
AIR PIPE
12" MIN.
5
ANTICIPATED
SNOW LEVEL
I407
OPTIONAL
INTAKE
I407
31