Lochinvar Power-Fin Series Installation And Service Manual page 19

Vertical Combustion Air Inlet
Follow the vertical combustion air inlet material and location
requirements as listed in the Vertical DirectAire Venting with
Rooftop Combustion Air section.
Multiple Vertical Direct Vent Installations
FIG. 22 Multiple Vertical Direct Vent Installations
The combustion air inlet caps for multiple appliance
installations must maintain the minimum 3 foot (0.91m)
clearance below the closest vertical flue outlet if within 10 feet
(3.05m). Multiple flue outlet caps may be installed side by side
and multiple air inlet caps may be installed side by side, but the
air inlet must always be at least 3 feet (0.91m) below the closest
flue outlet if the outlet is within 10 feet (3.05m). All clearance
and installation requirements in this section and the applicable
portions of the Category IV General Venting Information
section must be maintained on multiple appliance installations.
HORIZONTAL DIRECT VENT SYSTEMS
This vent option is only available on units with modulating
burner firing. The unit can be identified by the "Category IV"
and the "M" prefix on the firing controls as noted on the unit's
rating plate.
A Horizontal Direct Vent System is installed with a Category
IV flue and a separate combustion air pipe to the outdoors. The
Direct Vent System terminates both the flue and air inlet in the
same pressure zone. The combustion air cap and flue gas outlet
MUST be located on the same sidewall surface and in the same
pressure zone.
A Direct Vent System must have a dedicated air intake pipe.
Pipes for multiple units cannot be combined.
For venting flue products horizontally to the outdoors, follow
all requirements in the installation instructions for Sidewall
Venting. The termination point for the flue products must
follow the clearance requirements in the Sidewall Venting
section.
Follow all requirements in the General Category IV Venting
sections for proper installation and for venting flue products to
the outdoors with a sidewall termination. All other general
installation requirements must be followed.
The Direct Vent System always requires the installation of an
additional pipe to supply combustion air from outdoors directly
to the appliance. The air inlet pipe must use one of the
materials specified in the Air Inlet Pipe Materials section.
The maximum installed length of the air inlet pipe from the
appliance to the air inlet cap is 50 equivalent feet (15.2m) in
length. The maximum installed length of the flue pipe from the
appliance to the termination cap is 50 equivalent feet (15.2m)
in length. Subtract 5 feet (1.52m) of equivalent length for each
90° elbow installed in either the flue pipe or the air inlet pipe.
Subtract 2 1/2 feet (0.7m) of equivalent length for each 45°
elbow installed in either the flue or the air inlet pipe.
FIG. 23 Horizontal Direct Vent Installation with Sidewall
Combustion Air Inlet
Sidewall Combustion Air Inlet
Follow the sidewall combustion air inlet material and location
requirements as listed in the Vertical DirectAire Venting with
Sidewall Combustion Air section.
Horizontal Direct Vent Systems installed with sidewall
terminations for both combustion air and flue products must
purchase the termination caps from the appliance manufacturer.
The sidewall air inlet cap and sidewall vent cap for flue
products are available as a vent kit.
The part numbers for the required sidewall air inlet cap kit are
listed by unit size. The manufacturer, in accordance with CSA
International/CGA requirements, must furnish the sidewall air
inlet cap. Each kit includes the special combustion air inlet cap
for installation on an exterior sidewall. The sidewall air inlet
cap supplied in the kit is sized to provide combustion air for a
single appliance only.
Alternate Horizontal Direct Vent Kits with reduced vent sizes
are also approved and available from the manufacturer. These
kits include the inlet air cap, a vent reducer, and a reduced
diameter vent cap. See Table G for Standard and Alternate
Horizontal Direct Vent Kit numbers.
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