Camus Hydronics DFH/W500, Installation, Operation And Service Manual

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2.1.7 INLET CAP FOR ROOFTOP TERMINATION
The air inlet cap consists of two 90° elbows installed at the
point of termination for the air inlet pipe. The first 90° elbow is
installed on the rooftop at the highest vertical point of the air
inlet pipe and turned horizontal; the second 90° elbow is
screened and is installed on the horizontal outlet of the first
elbow and turned down. A 90° elbow and a 90° street elbow
may be used to make this assembly. If a straight piece of pipe
is used between the two elbows, it should not exceed 6"
(150mm) in length.
2.1.8 LOCATION OF A ROOFTOP AIR INLET AND VENT
CAPS
•
The point of termination for the combustion air inlet cap
MUST be at least 3 feet (0.91M) below the point of flue
gas termination (vent cap) if it is located within a 5 foot
(1.5M) radius of the flue outlet. Use care to ensure that the
90° elbow assembly is properly installed on the air inlet
pipe.
•
The termination point of the combustion air inlet cap must
be installed at least 3 feet (0.91M) above the rooftop and
above normal snow levels.
•
The vent cap assembly MUST be listed by nationally
recognized agencies.
•
Combustion air supplied from outdoors must be free of
contaminants. To prevent recirculation of flue products in
to the combustion air inlet, follow all instructions in this
section.
•
Incorrect installation and/or location of the air inlet cap can
allow flue products to be drawn back into the appliance.
This can result in incomplete combustion and potentially
hazardous levels of carbon monoxide in the flue products.
This will cause operational problems with the appliance
and if left uncorrected, will lead to conditions that can
cause personal injury or death.
2.1.9 AIR INLET DAMPER
In warmer climates, during cold weather, the use of ducted
outdoor air may result in the formation of condensation on the
interior panels of the combustion chamber. It may be possible
for this condensation to accumulate and drip out of the
appliance jacket. If this is not acceptable, it is advisable to
install a motorized combustion air damper in the combustion
air duct interlocked with the appliance’s start circuit. In cold
climates it is essential to provide a motorized air inlet damper
to control the supply of combustion air and prevent nuisance
condensation.
Figure 6: Air Inlet Damper Connection Inside J-Box
2.1.10 MASONARY CHIMNEY INSULATIONS
Always follow local codes when venting this appliance into a
masonry chimney. A standard masonry chimney must NOT be
used to vent the products of combustion from the flue of a
Condensing, positive or negative pressure appliance (Category
II or IV). If a masonry chimney is to be used, the chimney
MUST use a sealed, metallic, corrosion resistant liner
system to vent flue products from this high efficiency
appliance. Sealed, metallic, corrosion resistant liner
systems (AL29-4C or equivalent, single wall or double-
wall, or flexible or rigid metallic liners) must be rated for
use with a high efficiency condensing, positive pressure
vent system. Corrosion resistant chimney liner systems
are typically made from a high grade of corrosion resistant
stainless steel such as AL29-4C or equivalent. The
corrosion resistant liner must be properly sized and fully
sealed throughout the entire length. If the flue is contained
within the masonry chimney both the top and the bottom of
the masonry chimney must be capped and sealed to
provide a dead air space around the sealed corrosion
resistant metallic liner.
Consult with local code officials to determine code
requirements or the advisability of using a masonry
chimney with a sealed corrosion resistant liner
system.
2.1.11 VERTICAL VENTING TERMINATION
•
Follow Category II or IV vent termination and all
General instructions.
•
The vent terminal should be vertical and exhaust
outside the building at least 2 feet (0.61M) above the
highest point of the roof within a 10 foot (3.05M)
radius of the termination.
•
The vertical termination must be a minimum of 3 feet
(0.91M) above the point of exit.
•
A vertical termination less than 10 feet (3.05M) from a
parapet wall must be a minimum of 2 feet (0.61M)
higher than the parapet wall.
2.1.12 COMBINED COMBUSTION AIR INLET
The air inlet pipes from multiple appliances can be
combined to a single common connection if the common
air inlet pipe has a cross sectional area equal to or larger
than the total area of all air inlet pipes connected to the
common air inlet pipe.
Equivalent pipe diameter = Sq Root [(d
1
)
2
+ (d
2
)
2
+ (d
3
)
2
+
(d
4
)
2
+……+ (d
n
)
2
], d, pipe diameter
Example: What is equivalent pipe diameter of three
air inlet pipes, 8" (20.3 cm), 10” (25.4 cm) and 12”
(30.5 cm)
Equivalent pipe diameter = Sq Root [(8)
2
+ (10)
2
+ (12)
2
] =
Sq Root (308) = 17.5”, Select 18” (82.8 cm) diameter pipe
or larger.
The air inlet point for multiple boiler air inlets must be
provided with an exterior opening which has a free area
equal to or greater than the total area of all air inlet pipes
connected to the common air inlet. This exterior opening
for combustion air must connect directly to the outdoors.
The total length of the combined air inlet pipe must not
exceed a maximum of 100” (30.5M) equivalent feet. You
must deduct the restriction in area provided by any
screens, grills or louvers installed in the common air inlet
point. Screens, grills or louvers installed in the common air
inlet can reduce the free area of the opening from 25% to
75% based on the materials used. Calculate and
compensate accordingly for the restriction.
YELLOW
BLACK
BLUE
RED
24VAC, COMMON
CALL FOR HEAT
TO IGNITION
24VAC, CONST.
POWER