Directaire Vent Systems - Lochinvar Power-Fin Series Installation And Service Manual

DANGER
Failure to properly seal all joints and seams as required in
the air inlet piping may result in flue gas recirculation,
spillage of flue products and carbon monoxide emissions
causing severe personal injury or death.

DIRECTAIRE VENT SYSTEMS

A DirectAire vent system uses a flue to the sidewall or rooftop
with a separate combustion air pipe to the outdoors. The
DirectAire vent system may terminate the flue and the
combustion air inlet pipe in different pressure zones in any one
of four configurations. These are: (1) The flue on the rooftop
and combustion air intake on the sidewall. (2) Both the flue
and air inlet terminated on the rooftop using a Category I flue
for units with ON/OFF burner firing. (3) The flue terminated
on the sidewall and combustion air from the rooftop. (4) The
flue terminated on the sidewall and the combustion air intake
on a sidewall other than the sidewall where the flue is located.
All appliances are shipped from the factory with a flue outlet
that allows the connection of Category I or Category IV venting
systems. Check the vent category rating on your unit to ensure
that proper vent material is used. The optional DirectAire vent
systems require the installation of specific venting materials
that are purchased locally. Rooftop termination caps for flue
products and combustion air must be purchased locally.
Sidewall termination caps for flue products and combustion air
must be purchased from the manufacturer. The sidewall caps
for combustion air and flue products are available as vent kits.
The following is a detailed explanation of the installation
requirements for each venting system, components used, and
part numbers of vent kits for each model.
Follow all requirements for the type of vent materials used with
your unit.
A Category I or II vertical flue must follow the requirements in
the Vertical Negative Draft Venting sections. A Category IV
flue must follow the requirements under the Category IV
General Venting Information section. All other general venting
installation requirements must be followed.
The DirectAire 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.
Combined Combustion Air Inlet Points for DirectAire
Systems Only
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" (12.7cm) air inlet pipes (19.63 in
(126.6 cm 2 ) area each) have a total area of 39.26 in
requires an 8" (20.3 cm) (50.26 in
air inlet pipe.] 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
2 (253.3 cm 2
2 area) 324.3 cm 2 ) common
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 (15.2m) 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.
VERTICAL DIRECTAIRE VENTING
WITH ROOFTOP COMBUSTION AIR
FIG. 16 Vertical DirectAire Installation with Rooftop
Combustion Air Inlet
This venting option is only for units that operate with single
stage ON/OFF burner firing. These units will be marked as
Category I and have an "F" prefix on the firing controls as
noted on the rating plate. This venting option uses a Category
I, Type "B" double-wall vent material terminated at the rooftop
and a separate combustion air pipe also terminating at the
rooftop. The flue must be installed per all requirements in the
Conventional Vertical Negative Draft Venting section for a
Category I vent. Follow all requirements in the Conventional
Vertical Negative Draft Venting section for the materials
required to ensure that flue products are properly vented
vertically to the outdoors.
requirements must be followed.
combustion air intake terminate in the same pressure zones, but
because of the use of a Category I flue it does not meet the
specifications for a Direct Vent System.
The maximum installed length of the flue pipe from the
appliance to the termination cap is limited only by the
requirement to maintain a negative draft within the limits
specified in the Negative Draft General Venting Information
section.
2
Air Inlet Pipe Materials
)
A DirectAire 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.
14
All other general installation
The flue outlet and