Goodman GMP - Exterior Masonry Chimneys & Definitions; Exterior Masonry Chimneys; Definition of Terms

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EXTERIOR MASONRY CHIMNEYS - CATEGORY I furnaces only.
An exterior masonry chimney is defined as a “Masonry chimney exposed to the outdoors on
one or more sides below the roof line.”
The ability to use a clay lined masonry chimney depends on a parameter not associated
with interior chimneys. This variable is the geographic location of the installation. Research-
ers have discovered that the winter design temperatures have a direct impact on the suit-
ability of this type of venting.
In most situations, except in some Gulf Coast areas and Southern California, the existing
masonry chimneys will require a properly sized metallic liner.
DEFINITION of TERMS
Fan Assisted Combustion System - An ap-
pliance equipped with an integral mechanical
means to either draw or force the products of
combustion through the combustion chamber
and/or the heat exchanger.
FAN Min. - 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.
FAN Max. - Refers to the maximum input rat-
ing of a Category I with a fan assisted com-
bustion system that could be attached to the
vent.
NAT. Max. - Refers to the maximum appli-
ance input of a Category I appliance
equipped with a draft hood that could be at-
tached to the vent. There are no minimum
appliance ratings for draft hood equipped ap-
pliances.
FAN + FAN - Refers to the maximum com-
bined rating of two (2) or more fan assisted
appliances attached to a common vent.
FAN + NAT - Refers to the maximum com-
bined input rating of one or more fan-assisted
appliance and one or more draft hood
equipped appliances attached to the common
vent.
NAT + NAT - Refers to the maximum com-
bined input rating of two (2) or more draft
hood equipped appliances attached to the
common vent.
NA - Means not applicable due to physical or
geometric constraints.
Vent - 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 that con-
nects a fuel-gas burning appliance to a vent
or chimney.
Flue Collar - That portion of an appliance
designed for the attachment of a draft hood,
vent connector or venting system.
Categorized Vent Diameter - The minimum
permissible vent diameter for Category I ap-
pliance to maintain a non-positive vent static
pressure when tested according to nationally
recognized standards.