13
2
General venting
(continued)
Installation & Service Manual
Figure 2-7 E+ Vent with Roof Top Air
Vertical Roof Top Air Inlet
The air inlet cap for the vertical roof top air inlet is
assembled from components purchased locally. The air
inlet cap consist of two 90° ells installed at the point of
termination for the air inlet pipe. The first 90° ell is installed
on the roof top at the highest vertical point of the air inlet
pipe and turned horizontal, the second 90° ell is installed on
the horizontal outlet of the first ell and turned down. A 90°
ell and a 90° street ell may be used to make this assembly. If
a straight piece of pipe is used between the two ells, it should
not exceed 6” (51 mm) in length. The termination ell on the
air inlet must be located a minimum of 12” (30 cm) above the
roof or above normal levels of snow accumulation.
EXHAUST
TERMINAL
INTAKE
TERMINAL
TYPICAL SOIL PIPE
IF FLUE PASSES THROUGH A
SLOPED OR PEAKED ROOF SEE
VENT TERMINATION IMAGES
NOTE: IF FLUE PASSES
THROUGH A FLAT ROOF
WITH PARAPET WALLS SEE
FLAT ROOF TERMINATION IMAGES
Figure 2-8 Air Inlet Cap for Roof Top Termination
The point of termination for the combustion air inlet cap
MUST
be at least 2 feet (61 cm) below the point of flue gas
termination (vent cap) if it is located within 10’ (3.05 m) of
the flue outlet. Use care to ensure that the 90° ell assembly
is properly installed on the air inlet pipe.
The combustion air inlet cap must not be installed closer than
10 feet (3.05 m) from an inside corner of an L-shaped structure.
The combustion air inlet cap must be installed at least one
foot (30 cm) above the roof top and above normal snow
levels.
Incorrect installation and/or location of the air inlet cap
can allow the discharge of flue products to be drawn into
the combustion process on the heater. This can result in
incomplete combustion and potentially hazardous levels
of carbon monoxide in the flue products. This will cause
operational problems with the heater and possible spillage
of flue products which can cause personal injury, death or
property damage
Combined Air Inlet Points
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. [Example: two 5" air inlet pipes
(19.6 in
2
area each) have a total area of 39.2 in
2
require a
8"(50.3 in
2
area) common air inlet pipe.] The air inlet point
for multiple appliance 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 50 (15.25 m) equivalent feet. You must deduct the
restriction in area provided by any screens, grills or louvers
installed in the common air inlet point. These are common
on the sidewall air inlet openings. 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.
Summary of Contents for Efficiency-Pac EW 150 -- 300
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