•
Use AL29-4C or equivalent vent material
and follow “Direct Venting” Procedure.
1D. Direct Venting Procedure
1. Determine entire vent length and num-
ber of elbows required. Actual venting
system must not exceed limitations in
Table 1 below or as stated in ANSI Z
223.1.
2. Use 3-inch diameter vent pipe pitched
up from Combination Heater. Do not
connect other appliances to this vent.
3. Seal all AL29-4C vent joints with
approved silicone sealant (400ºF -
Dow 732 RTV or equivalent)
4. MAINTAIN TWO-INCH CLEAR-
ANCE from combustible materials to
vent pipe.
5. Long horizontal vent runs should be
supported with appropriate hangers.
Ensure vent pipe is pitched up from the
unit at 1/4” per foot minimum.
6. Direct sidewall vent termination:
• Masonary walls - make a 3 1/2 to 4 -
inch diameter hole.
• Combustible material - requires 7-
inch hole. Make sheet metal plate
with 3-inch hole to cover opening.
• Must be in the same pressure zone
(i.e. same outside wall) as the com-
bustion air inlet.
7
INSTALLATION
Total length for 3" AL29-4C Venting System and 3"
Combustion Air Inlet vs number of elbows
Maximum length - feet
50
45
40
35
Maximum number of elbows
1
2
3
4
;
;
;
;
;;
;;
;;
;;
Triangle
Tu b e
Sealed chimney
opening
3" Stainless steel vent pipe
vertical run through
entire chimney
Seal all joints
inside and outside
of chimney
Pitch up
1/4"/Ft
Air Intake
Grade level
Flashing
recommended
to direct exhaust
away from wall
12" Min.
Vent Termination
Anchored fastners
Metal Plate
Caulk opening
Cement
mortar
seal
Direct Venting thru Non-Combustible Wall
Direct Venting through
Outside Chimney
Fig. 2
Fig. 3
Table 1
