NFI HEARTH SPECIALIST STUDY GUIDE ANSWERS
AND QUESTIONS SET A+
Air Infiltration - ✔✔typically, the passing of air into the house through small cracks or
gaps inherent to the structure. Affected by temperature difference between the inside
and outside of the structure, and air pressure factors (e.g., wind, the operation of solid
fuel appliances or electrical appliances such as fans).
✔✔Air Inlet - ✔✔the designed port(s) of entry for combustion air in a controlled
combustion, solid fuel burning appliance
✔✔Air Inlet Control - ✔✔the means by which the amount of air entering the air inlet is
regulated. Also referred to as air control
✔✔Air Supply - ✔✔broadly, the air that is supplied to the firebox of the wood burning
appliance
✔✔Air-to-fuel Ratio - ✔✔the ratio of air and fuel, by weight, in a solid fuel appliance. It
should be noted that 1 pound of dry air occupies a volume of 13.315 cubic feet at 70
degrees Fahrenheit. Therefore, 35 pounds of air, the typical amount of air necessary to
burn 1 pound of wood in a fireplace, occupies 466 cubic feet.
✔✔Aldehydes - ✔✔class of compounds with distinct pungent odor, produced during
incomplete combustion of fuel gas
✔✔ANSI - ✔✔American National Standards Institute. The coordinating organization for
federated national standards system, consisting of 900 companies and 200 trade,
technical, professional, labor, and consumer organizations
✔✔Appliance - ✔✔a solid fuel burning product
✔✔Appliance Regulator - ✔✔the appliance component, usually part of the combustion
valve that maintains constant gas pressure
,✔✔Appliance to Fuel - ✔✔means of venting a solid fuel appliance (including fireplace
inserts) into masonry fireplace chimneys; the stainless steel connector passes from the
appliance to the first clay flue liner. Also referred to as direct connection
✔✔Approved - ✔✔acceptable to the authority having jurisdiction
✔✔Ash - ✔✔noncombustible solid byproduct of solid fuel combustion
✔✔Authority Having Jurisdiction (AHJ) - ✔✔The organization, office, or individual
responsible for "approving" equipment, materials, an installation, or a procedure
✔✔Automatic Gas Control Valve (combination valve) - ✔✔gas valve which combines
control functions; usually consists of gas manual valve assembly; pilot safety shutoff
system, diaphragm valve, gas pressure regulator, and valve operator
✔✔Baffle - ✔✔an obstructing device or partition in a solid fuel appliance, used to direct
the flow of gases and heat
✔✔Blower Door - ✔✔a diagnostic toll used to measure the tightness of buildings.
Consists of a calibrated fan for measuring airflow rate and a pressure sensing device to
determine house pressure levels
✔✔Breaching - ✔✔refers to the chimney connector access (hole) in a masonry chimney
✔✔British Thermal Unit (BTU) - ✔✔a measure of heat energy; the amount of heat
required to raise the temperature of one pound of water one degree Fahrenheit at sea
level
✔✔Burn Rate - ✔✔combustion rate, usually expressed in pounds of fuel consumed per
hour
✔✔Butane - ✔✔a colorless, odorless, nontoxic gas; not generally used in hearth
appliances
✔✔Bypass Damper - ✔✔term specifically referring to the movable plate in some
catalytic wood burning appliances that in one position channels the flue gases through
the catalytic combustor, and in one position channels the smoke to "bypass", or not go
through, the catalytic combustor. On some noncatalytic appliances, a movable plate that
redirects and increases residence time of gases
✔✔Can - ✔✔holder for catalytic combustor usually made of stainless steel
✔✔Canning System - ✔✔device surrounding catalytic combustor, usually consisting of
insulation mat and stainless steel can, or holder
, ✔✔Cap - ✔✔also termination cap. covering for factory built chimney that minimizes
effect of wind, and prevents entry of rain, snow, and debris
✔✔Carbon Dioxide (CO2) - ✔✔colorless, odorless noncombustible gas produced by the
complete combustion of carbonaceous fuel; is nontoxic
✔✔Carbon Monoxide (CO) - ✔✔colorless, odorless combustible, and toxic gas
produced by the incomplete combustion of carbonaceous fuel
✔✔Catalyst - ✔✔a substance that increases the rate of a chemical reaction without
being consumed in the process. In solid fuel use, usually the precious metals palladium
and platinum. Applied to the wash coat of the catalytic combustor
✔✔Catalytic Combustor - ✔✔device designed to increase combustion efficiency by
lowering flue gas ignition temperatures. Consists of substrate, wash coat, catalysts, and
canning system
✔✔Cement Board - ✔✔cement and reinforcing fibers formed into a sheet, often used as
a tile backing board. Used in the hearth industry for thermal resistance properties as
floor protection
✔✔Chase - ✔✔a structure built around, and enclosing, portions of the chimney and in
some case, housing the appliance
✔✔Chimney - ✔✔a portion of the venting system, through which flue gases are vented
to the outdoors and by which penetrated combustible surfaces are protected; a primarily
vertical shaft enclosing at least one flue, the design of which results in a natural draft
✔✔Chimney Breaching - ✔✔a means of venting a solid fuel appliance into masonry
fireplace chimneys; the chimney connector passes through the chimney wall to the
inside of the flue liner by means of a thimble or approved passthrough device
✔✔Chimney Capacity - ✔✔refers to the volume of flue gases the chimney is able to
handle; is affect by draft
✔✔Chimney Connector - ✔✔the portion of the venting system between the appliance
and the chimney. commonly called "stovepipe"
✔✔Cleanout Door - ✔✔means for closing and sealing the opening provided for
inspection and removal of creosote and other chimney deposits; should be well sealed
against air infiltration
AND QUESTIONS SET A+
Air Infiltration - ✔✔typically, the passing of air into the house through small cracks or
gaps inherent to the structure. Affected by temperature difference between the inside
and outside of the structure, and air pressure factors (e.g., wind, the operation of solid
fuel appliances or electrical appliances such as fans).
✔✔Air Inlet - ✔✔the designed port(s) of entry for combustion air in a controlled
combustion, solid fuel burning appliance
✔✔Air Inlet Control - ✔✔the means by which the amount of air entering the air inlet is
regulated. Also referred to as air control
✔✔Air Supply - ✔✔broadly, the air that is supplied to the firebox of the wood burning
appliance
✔✔Air-to-fuel Ratio - ✔✔the ratio of air and fuel, by weight, in a solid fuel appliance. It
should be noted that 1 pound of dry air occupies a volume of 13.315 cubic feet at 70
degrees Fahrenheit. Therefore, 35 pounds of air, the typical amount of air necessary to
burn 1 pound of wood in a fireplace, occupies 466 cubic feet.
✔✔Aldehydes - ✔✔class of compounds with distinct pungent odor, produced during
incomplete combustion of fuel gas
✔✔ANSI - ✔✔American National Standards Institute. The coordinating organization for
federated national standards system, consisting of 900 companies and 200 trade,
technical, professional, labor, and consumer organizations
✔✔Appliance - ✔✔a solid fuel burning product
✔✔Appliance Regulator - ✔✔the appliance component, usually part of the combustion
valve that maintains constant gas pressure
,✔✔Appliance to Fuel - ✔✔means of venting a solid fuel appliance (including fireplace
inserts) into masonry fireplace chimneys; the stainless steel connector passes from the
appliance to the first clay flue liner. Also referred to as direct connection
✔✔Approved - ✔✔acceptable to the authority having jurisdiction
✔✔Ash - ✔✔noncombustible solid byproduct of solid fuel combustion
✔✔Authority Having Jurisdiction (AHJ) - ✔✔The organization, office, or individual
responsible for "approving" equipment, materials, an installation, or a procedure
✔✔Automatic Gas Control Valve (combination valve) - ✔✔gas valve which combines
control functions; usually consists of gas manual valve assembly; pilot safety shutoff
system, diaphragm valve, gas pressure regulator, and valve operator
✔✔Baffle - ✔✔an obstructing device or partition in a solid fuel appliance, used to direct
the flow of gases and heat
✔✔Blower Door - ✔✔a diagnostic toll used to measure the tightness of buildings.
Consists of a calibrated fan for measuring airflow rate and a pressure sensing device to
determine house pressure levels
✔✔Breaching - ✔✔refers to the chimney connector access (hole) in a masonry chimney
✔✔British Thermal Unit (BTU) - ✔✔a measure of heat energy; the amount of heat
required to raise the temperature of one pound of water one degree Fahrenheit at sea
level
✔✔Burn Rate - ✔✔combustion rate, usually expressed in pounds of fuel consumed per
hour
✔✔Butane - ✔✔a colorless, odorless, nontoxic gas; not generally used in hearth
appliances
✔✔Bypass Damper - ✔✔term specifically referring to the movable plate in some
catalytic wood burning appliances that in one position channels the flue gases through
the catalytic combustor, and in one position channels the smoke to "bypass", or not go
through, the catalytic combustor. On some noncatalytic appliances, a movable plate that
redirects and increases residence time of gases
✔✔Can - ✔✔holder for catalytic combustor usually made of stainless steel
✔✔Canning System - ✔✔device surrounding catalytic combustor, usually consisting of
insulation mat and stainless steel can, or holder
, ✔✔Cap - ✔✔also termination cap. covering for factory built chimney that minimizes
effect of wind, and prevents entry of rain, snow, and debris
✔✔Carbon Dioxide (CO2) - ✔✔colorless, odorless noncombustible gas produced by the
complete combustion of carbonaceous fuel; is nontoxic
✔✔Carbon Monoxide (CO) - ✔✔colorless, odorless combustible, and toxic gas
produced by the incomplete combustion of carbonaceous fuel
✔✔Catalyst - ✔✔a substance that increases the rate of a chemical reaction without
being consumed in the process. In solid fuel use, usually the precious metals palladium
and platinum. Applied to the wash coat of the catalytic combustor
✔✔Catalytic Combustor - ✔✔device designed to increase combustion efficiency by
lowering flue gas ignition temperatures. Consists of substrate, wash coat, catalysts, and
canning system
✔✔Cement Board - ✔✔cement and reinforcing fibers formed into a sheet, often used as
a tile backing board. Used in the hearth industry for thermal resistance properties as
floor protection
✔✔Chase - ✔✔a structure built around, and enclosing, portions of the chimney and in
some case, housing the appliance
✔✔Chimney - ✔✔a portion of the venting system, through which flue gases are vented
to the outdoors and by which penetrated combustible surfaces are protected; a primarily
vertical shaft enclosing at least one flue, the design of which results in a natural draft
✔✔Chimney Breaching - ✔✔a means of venting a solid fuel appliance into masonry
fireplace chimneys; the chimney connector passes through the chimney wall to the
inside of the flue liner by means of a thimble or approved passthrough device
✔✔Chimney Capacity - ✔✔refers to the volume of flue gases the chimney is able to
handle; is affect by draft
✔✔Chimney Connector - ✔✔the portion of the venting system between the appliance
and the chimney. commonly called "stovepipe"
✔✔Cleanout Door - ✔✔means for closing and sealing the opening provided for
inspection and removal of creosote and other chimney deposits; should be well sealed
against air infiltration
