Lochinvar Power-Fin Series Installation And Service Manual page 8

Category IV General Venting Information
A Category IV venting system operates with a positive pressure
in the vent. This positive pressure is generated by the internal
combustion air blower which operates the combustion process
and also exhaust the flue products from the building. The
Category IV flue from this appliance cannot be combined with
the vent from any other appliance. The Category IV flues from
multiple appliances cannot be combined into a common vent.
The Category IV flue from this appliance must be a dedicated
stack. The flue from this Category IV appliance must have all
vent joints and seams sealed gastight. A Category IV vent
system has specific vent material and installation requirements.
The flue products in the vent system may be cooled below their
dew point and form condensate in the flue. The flue materials
used for a Category IV vent must be resistant to any corrosive
damage from flue gas condensate. The flue from a Category IV
vent system must have a condensate drain with provisions to
properly collect and dispose of any condensate that may occur
in the venting system.
The connection from the appliance vent to the stack or vent
termination outside the building must be made with listed
Category IV vent material and must be as direct as possible.
The Category IV vent and accessories such as firestop spacers,
thimbles, caps, etc., must be installed in accordance with the
vent manufacturer's instructions.
firestop must provide correct spacing to combustible surfaces
and seal to the vent connector on the upper and lower sides of
each floor or ceiling through which the vent connector passes.
Any vent materials specified must be listed by a nationally
recognized test agency for use as a Category IV vent material.
The venting system must be planned so as to avoid possible
contact with concealed plumbing or electrical wiring inside
walls, floors, or ceilings. Locate the appliance as close as
possible to a chimney or gas vent.
Horizontal portions of the venting system shall be supported to
prevent sagging. Horizontal runs should slope upwards not less
than 1/4 inch per foot from the drain tee installed in the flue to
the vertical portion of the flue or to the vent terminal on
sidewall venting installations. This ensures proper removal of
any condensate that may form in the flue.
installation instructions from the vent material manufacturer.
Do not use an existing chimney as a raceway if another
appliance or fireplace is vented through the chimney. The
weight of the venting system must not rest on the unit.
Adequate support of the venting system must be provided in
compliance with local codes and other applicable codes. All
connections should be secured and sealed per the vent
manufacturer's specifications.
Vent connectors serving appliances vented by natural draft shall
not be connected to any portion of the Category IV positive
pressure vent system used by this appliance. Connection of a
negative draft flue into the positive pressure stack from this
appliance may cause flue products to be discharged into an
occupied living space causing serious health injury.
When a Category IV vent system is disconnected for any
The vent connector and
Follow the
reason, the flue must be reassembled and resealed according to
the vent manufacturer's instructions.
The flue may terminate either vertically at the rooftop or
horizontally on a sidewall.
termination sections for information about recommended vent
termination location and clearances.
When the appliance is installed as either a Category II or
Category IV vent appliance, unique venting guidelines
will apply. Refer to the appropriate section of the
Installation and Service Manual for specific instructions
for Category II or Category IV vent installations.
ROOFTOP VENT TERMINATION
CLEARANCES FOR CATEGORY I, II,
OR IV VERTICAL VENTING SYSTEMS
FIG. 7 Vent Termination from Peaked Roof - 10' or Less
from Ridge
FIG. 8 Vent Termination from Peaked Roof More than 10'
from Ridge
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.
8
Refer to the specific vent
WARNING