Bard Bayrd Furnace 403293A - Manual (Page 40)

VENTING REQUIREMENTS FOR CATEGORY I APPLIANCES
INTRODUCTION
This booklet contains the current definitions,
instructions, and tables necessary to vent todays
modern Category I Gas Fired Appliance. A variety
of definitions of new terms describing today's gas
appliances are included to supplement the actual
venting tables which have been generated to
correctly vent various combinations of Category I
Appliances using Type B or single*wall metal vent
connectors attached to Type B vents or masonry
chimneys. Tables are also included covering similar
venting material combinations when applied to
common venting arrangements of two or more
appliances.
Finally, a series of examples are presented
demonstrating how the vent tables are used to
size the vent connector and the vertical vent for a
variety of typical applications.
I I. DEFINITION OF TERMS
Tan Assisted
Combustion
System"
"FAN Min"
"FAN Max"
"NAT Max"
"FAN+FAN"
An appliance equipped with an
integral mechanical means to
either draw or force products of
combustion
through the
combustion chamber and/or
heat exchanger.
refers to the minimum
appliance input rating of a
Category I appliance with a fan-
assisted combustion system
that could be attached to the
vent.
refers to the maximum
appliance input rating of a
Category I appliance with a fan-
assisted combustion system
that could be attached to the
vent.
refers to the maximum
appliance input rating of a
Category I appliance equipped
with a drafthood that could be
attached to the vent. There are
no minimum appliance input
ratings for drafthood-equipped
appliances.
refers to the maximum
combined input rating of two or
more fan-assisted appliances
attached to the common vent.
"FAN+NAT" refers to the maximum
combined input rating of one or
more fan-assisted appliance
and one or more drafthood-
equipped appliance attached
to the common vent.
"NAT+NAT" refers to the maximum
combined input rating of two or
more
drafthood-equipped
appliances attached to the
common vent.
"NR" means not recommended due
to potential for condensate
formation and/or pressurization
of the venting system.
"NA" means not applicable due to
physical or geometric
constraints.
DraftHood A device built into an appliance,
or made a part of the vent
connector from an appliance,
which is designed to (1)
provide for the ready escape of
the flue gases from the
appliance in the event of no
draft, backdraft, or stoppage
beyond the drafthood, (2)
prevent a backdraft from
entering the appliance, and (3)
neutralize the effect of stack
action of the chimney or gas
vent upon the operation of the
appliance.
A passageway used to convey
flue gases from gas utilization
equipment, or their vent
connectors, to the outside
atmosphere.
Vent Connector The pipe or duct which
connects a fuel-gas burning
appliance to a vent or chimney.
Vent
Flue Collar
Categorized
Vent Diameter
That portion of an appliance
designed for the attachment of
a drafthood, vent connector, or
venting system.
The minimum vent diameter
permissible for Category t
appliances
to maintain a
nonpositive vent static pressure
when tested in accordance with
nationally recognized standards.
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