Dunkirk Q90-200 Series II - Manual (Page 16)

16
6 - COMBUSTION AIR/ VENT REQUIREMENTS
Figure 12 - Concentric Vent
3” Diameter PVC
Vent/Exhaust
1½”
4½” Dia.
31⅞”
A
A
B
B
C
C
D
E
F
G
G 3” Diameter PVC
Intake/Combustion Air
46¾”
Dimension
1³⁄16” D
E
F
Dimension
Figure 13 - Concentric Vent Roof Installation
• Combustion air must be clean outdoor air. Do not take
combustion air from inside structure because that air
is frequently contaminated by halogens, which includes
fluorides, chlorides, phosphates, bromides and iodides.
These elements are found in aerosols, detergents,
bleaches, cleaning solvents, salts, air fresheners, paints,
adhesives, and other household products. Typical areas
of contamination include dry cleaning facilities, swimming
pools, beauty shops, new building construction, air
conditioning equipment. For example combustion air
intake near swimming pool chemicals will damage any
condensing boiler.
• Locate combustion air inlet as far away as possible from
swimming pool and swimming pool pump house.
• All combustion air and vent pipes must be airtight and
watertight.
• Follow instructions in this manual for combustion air and
vent piping termination.
• Use of concentric vent termination refer to Figures 10, 11
and 12 for proper setup.
• Vent connections serving appliances vented by natural
draft shall not be connected into any portion of mechanical
draft systems operating under positive pressure.
• Fully support all vent piping. Use hangers at intervals to
prevent pipe from sagging.
WARNING
Fire, explosion, asphyxiation hazard. Solvent
cements are combustible. Keep away from heat,
sparks, or open flame. Use only in well ventilated
areas. Avoid breathing in vapor or allowing contact
with skin or eyes. Improper installation could result
in death or serious injury. Read this manual and
understand all requirements before beginning
installation.
!
A Roof Boot/Flashing
(Field Supplied)
B Elbow (Field Supplied)
C Support (Field Supplied)
D
Maintain 12” (305mm),
18” (457mm)
Minimum Clearance
Above Highest
Anticipated Snow
Level.
Maximum of (610mm)
Above Roof.
WARNING
Fire, asphyxiation hazard. Covering non-metallic
vent pipe and fittings with thermal insulation shall
be prohibited. Improper installation could result in
death or serious injury.
!
NOTICE
Properly support venting. Boiler is not designed to
bear weight of venting system.