Sidewall direct venting – Lochinvar KNIGHT XL 801 User Manual
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4
Sidewall direct venting
SIDEWALL
TERMINATION PLATE
VENT
PIPING
GALVANIZED
THIMBLE 
(WHEN REQUIRED BY LOCAL CODES)
ELBOW
ELBOW
AIR PIPING
BIRD SCREEN
BIRD SCREEN
Figure 4-5B A Typical Sidewall Termination Assembly 
- Models 400 - 801 PVC/CPVC or Stainless Steel
Termination and fi ttings
1. Prepare the vent termination elbow and the air termination
elbow (FIG. 4-5B) by inserting bird screens. Bird screens 
can be obtained locally. 
2. When completed, the air termination coupling must be
oriented at least 12 inches (305 mm) below the vent 
termination and at least 12 inches (305 mm) above grade or 
snow line as shown in FIG. 4-1A, page 23.
3. Maintain the required dimensions of the fi nished
termination piping as shown in FIG. 4-1A, page 23.
4. Do not extend exposed vent pipe outside of building more
than shown in this document. Condensate could freeze and 
block vent pipe.
5. PVC/CPVC terminations are designed to accommodate any
wall thickness of standard constructions per the directions 
found in this manual.
All vent pipes and air inlets must terminate 
at the same height to avoid possibility of 
severe personal injury, death, or substantial 
property damage.
Multiple vent/air terminations
1. When terminating multiple Knight XL’s terminate
each vent/air connection as described in this manual
(FIG. 4-6A).
2. Place wall penetrations to obtain minimum clearance of
12 inches (305 mm) between vent pipe and adjacent air 
inlet elbow, as shown in FIG. 4-6A for U.S. installations. 
For Canadian installations, provide clearances required 
by CSA B149.1 Installation Code.
3. The air inlet of a Knight XL is part of a direct vent
connection. It is not classifi ed as a forced air intake with 
regard to spacing from adjacent boiler vents.
VENT
12” (305 MM) MIN
15” (381 MM) MAX
12” (305 MM) MIN. BETWEEN EDGE 
OF AIR PIPE AND ADJACENT VENT
PIPE
AIR
Figure 4-6B Alternate Multiple Vent Terminations 
w/Field Supplied Fittings (must also comply with 
Figure 4-1B)
ƽ WARNING
Prepare wall penetrations (Alternate - Field
Supplied Option)
1. Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as 
 
close as desired to the air pipe outside diameter.
2. Vent
pipe
penetration:
a. Cut a hole for the vent pipe. For either combustible 
 
or noncombustible construction, size the vent pipe
hole with at least a 1/2 inch clearance around the vent
pipe outer diameter:
 • 5½ inch hole (140 mm) hole for 4 inch (102 mm) 
 
vent pipe
 • 7½ inch hole (191 mm) hole for 6 inch (152 mm) 
 vent pipe
b. Insert a galvanized metal thimble in the vent pipe 
 
hole as shown in FIG. 4-5B.
3. Use a sidewall termination plate as a template for correct
location of hole centers.
4. Follow all local codes for isolation of vent pipe when passing
through fl oors or walls.
5. Seal exterior openings thoroughly with exterior caulk.
12" MIN. BETWEEN EDGE OF AIR
INLET AND ADJACENT VENT OUTLET
VENT / AIR
TERMINATION
VENT
AIR
Figure 4-6A Multiple Vent Terminations (must also 
comply with Figure 4-1A)
Installation & Operation Manual
6. Stainless steel terminations are designed to penetrate walls
with a thickness up to 9.25 inches of standard construction.
