NFI HEARTH SPECIALIST TEST PAPER ANSWERS
AND QUESTIONS SET A+
✔✔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
✔✔Clearances - ✔✔minimum distance which must be maintained between a heat
source such as an appliance or vent and combustible surfaces
✔✔Cold Junction - ✔✔non-heated end of the thermocouple/thermopile
✔✔Combustible Material - ✔✔material made of or surfaced with wood, compressed
paper, plant fibers, or other material that will ignite and burn, as applied to materials
adjacent to or in contact with heat-producing appliances, chimney connectors, steam
and hot water pipes and warm air ducts,. such material shall be considered as
combustible even though flame-proofed, fire retardant treated, or plastered
✔✔Combustibles - ✔✔material made of or surfaced with wood, compressed paper,
plant fibers, plastics, or other material that will ignite and burn in the presence of flame
and/or heat, whether flameproofed or not, or whether plastered or not
✔✔Combustion - ✔✔the process of burning, or oxidation accompanied by heat. When
sufficiently rapid, also accompanied by light. Rapid oxidation of fuel gases accompanied
by the production of heat, or heat and light. Requires proper amounts of fuel, oxygen,
and heat
✔✔Combustion Ratio - ✔✔required amount of air that must mix with 1 cubic foot of gas
to have complete combustion
✔✔Compression Station - ✔✔place where pressure of natural gas is increased before it
continues farther along the pipeline
,✔✔Condensate - ✔✔the liquid that separates from a gas (including fuel gases) due to a
reduction in temperature
✔✔Controlled Combustion - ✔✔complete burning of fuel with a steady flame when fuel
and air supplied at proper rate. Contrast with explosion
✔✔Controlled Combustion Appliances - ✔✔solid fuel appliances with relatively tight
seals. The amount of air entering the air inlet, thus the combustion rate in the firebox is
operator controlled
✔✔Convection - ✔✔the transmission or heat by the circulation of a fluid (air or water),
caused by differences in temperature (and therefore density)
✔✔Cookstove - ✔✔a controlled combustion solid fuel appliance with at least one oven
and a surface designed for cooking
✔✔Cornice - ✔✔overhang of a pitched roof, usually consisting of a fascia board, a soffit
and appropriate trim moldings
✔✔Cricket - ✔✔peaked secondary roof section constructed on top of, and
perpendicular to the primary roof to divert water (also known as saddle)
✔✔Cripple Stud - ✔✔short studs placed between the header and a top plate or between
a sill and sole plate
✔✔Crown - ✔✔beveled or sloping surface that terminates a masonry chimney; seals
the flue; provides drainage slope for rain and snow. Recommended that gap (with
flexible sealer) be maintained between flue liner and crown and that crown extend at
least 2 inches beyond exterior chimney wall. Referred to as chimney cap in IRC and
ASTM C 1283
✔✔Damper - ✔✔movable plate that directs the flow of gases and air in a solid fuel
appliance or chimney connector. In fireplaces, a pivoted metal plate, set just above the
firebox, primarily used to close off the chimney when not in use. Also a hinged device
located at the top of the chimney, controlled by a cable that extends to the firebox
✔✔Diaphragm - ✔✔part of pressure regulator that responds to changes in gas pressure
to maintain constant outgoing pressure
✔✔Diethanolamine Treatment - ✔✔chemical process of removing hydrogen sulfide and
carbon dioxide from gas (sweetening the gas)
✔✔Directional Hood - ✔✔a part of the pilot burner that directs the flame against a
control device and then out across the main burner
, ✔✔Direct Spark Ignition - ✔✔a type of electronic ignition system that ignites the gas
directly at the main burner by means of a spark
✔✔Direct Vent - ✔✔method of venting appliance whereby all air for combustion is
derived directly from the outside atmosphere and all flue gases are discharged directly
to the outside atmosphere
✔✔Distillation - ✔✔separation of solids and liquids from gases by application of heat.
Method of extracting LPG from wet natural gas
✔✔Draft Hood - ✔✔a device built into an appliance or made a part of the flue or vent
connector from the appliance designed to (1) provide for the ready escape of flue gases
in the event of no draft, back draft, or stoppage beyond the draft hood; (2) prevent a
back draft from entering the appliance; and (3) neutralize the effect of stack action of the
chimney or gas vent upon the operation of the appliance. also known as draft diverter
✔✔Drip - ✔✔in gas piping, a tee device used to collect condensate from gases.
installed so that they can be serviced to remove condensate. also known as drip leg
✔✔Drywall - ✔✔(or Gypsum Wallboard (GWB), sheet rock, plasterboard, wall board, or
gypsum) a manufactured panel made out of gypsum plaster and encased in a thin
cardboard or other material
✔✔Eaves - ✔✔the horizontal exterior roof overhang
✔✔Elbow - ✔✔the portion of the connector or chimney that turns or offsets the direction
of the chimney
✔✔Electronic Sniffer - ✔✔a device that emits a loud, piercing noise in the presence of
very small amounts of certain gases. Used in gas supply line and appliance leak
detection
✔✔Ethane - ✔✔a hydrocarbon compound found in natural gas
✔✔Excess Air - ✔✔air in the firebox or fire chamber of a solid fuel appliance that is not
used in combustion reactions (and exhausts through the venting system)
✔✔Excess Flow Valve (EFV) - ✔✔a gas valve designed to activate when the fuel gas
passing through it exceeds a prescribed flow rate
✔✔Explosion - ✔✔repaid burning with an improper rate of air and fuel; not under control
and with excessive pressure
AND QUESTIONS SET A+
✔✔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
✔✔Clearances - ✔✔minimum distance which must be maintained between a heat
source such as an appliance or vent and combustible surfaces
✔✔Cold Junction - ✔✔non-heated end of the thermocouple/thermopile
✔✔Combustible Material - ✔✔material made of or surfaced with wood, compressed
paper, plant fibers, or other material that will ignite and burn, as applied to materials
adjacent to or in contact with heat-producing appliances, chimney connectors, steam
and hot water pipes and warm air ducts,. such material shall be considered as
combustible even though flame-proofed, fire retardant treated, or plastered
✔✔Combustibles - ✔✔material made of or surfaced with wood, compressed paper,
plant fibers, plastics, or other material that will ignite and burn in the presence of flame
and/or heat, whether flameproofed or not, or whether plastered or not
✔✔Combustion - ✔✔the process of burning, or oxidation accompanied by heat. When
sufficiently rapid, also accompanied by light. Rapid oxidation of fuel gases accompanied
by the production of heat, or heat and light. Requires proper amounts of fuel, oxygen,
and heat
✔✔Combustion Ratio - ✔✔required amount of air that must mix with 1 cubic foot of gas
to have complete combustion
✔✔Compression Station - ✔✔place where pressure of natural gas is increased before it
continues farther along the pipeline
,✔✔Condensate - ✔✔the liquid that separates from a gas (including fuel gases) due to a
reduction in temperature
✔✔Controlled Combustion - ✔✔complete burning of fuel with a steady flame when fuel
and air supplied at proper rate. Contrast with explosion
✔✔Controlled Combustion Appliances - ✔✔solid fuel appliances with relatively tight
seals. The amount of air entering the air inlet, thus the combustion rate in the firebox is
operator controlled
✔✔Convection - ✔✔the transmission or heat by the circulation of a fluid (air or water),
caused by differences in temperature (and therefore density)
✔✔Cookstove - ✔✔a controlled combustion solid fuel appliance with at least one oven
and a surface designed for cooking
✔✔Cornice - ✔✔overhang of a pitched roof, usually consisting of a fascia board, a soffit
and appropriate trim moldings
✔✔Cricket - ✔✔peaked secondary roof section constructed on top of, and
perpendicular to the primary roof to divert water (also known as saddle)
✔✔Cripple Stud - ✔✔short studs placed between the header and a top plate or between
a sill and sole plate
✔✔Crown - ✔✔beveled or sloping surface that terminates a masonry chimney; seals
the flue; provides drainage slope for rain and snow. Recommended that gap (with
flexible sealer) be maintained between flue liner and crown and that crown extend at
least 2 inches beyond exterior chimney wall. Referred to as chimney cap in IRC and
ASTM C 1283
✔✔Damper - ✔✔movable plate that directs the flow of gases and air in a solid fuel
appliance or chimney connector. In fireplaces, a pivoted metal plate, set just above the
firebox, primarily used to close off the chimney when not in use. Also a hinged device
located at the top of the chimney, controlled by a cable that extends to the firebox
✔✔Diaphragm - ✔✔part of pressure regulator that responds to changes in gas pressure
to maintain constant outgoing pressure
✔✔Diethanolamine Treatment - ✔✔chemical process of removing hydrogen sulfide and
carbon dioxide from gas (sweetening the gas)
✔✔Directional Hood - ✔✔a part of the pilot burner that directs the flame against a
control device and then out across the main burner
, ✔✔Direct Spark Ignition - ✔✔a type of electronic ignition system that ignites the gas
directly at the main burner by means of a spark
✔✔Direct Vent - ✔✔method of venting appliance whereby all air for combustion is
derived directly from the outside atmosphere and all flue gases are discharged directly
to the outside atmosphere
✔✔Distillation - ✔✔separation of solids and liquids from gases by application of heat.
Method of extracting LPG from wet natural gas
✔✔Draft Hood - ✔✔a device built into an appliance or made a part of the flue or vent
connector from the appliance designed to (1) provide for the ready escape of flue gases
in the event of no draft, back draft, or stoppage beyond the draft hood; (2) prevent a
back draft from entering the appliance; and (3) neutralize the effect of stack action of the
chimney or gas vent upon the operation of the appliance. also known as draft diverter
✔✔Drip - ✔✔in gas piping, a tee device used to collect condensate from gases.
installed so that they can be serviced to remove condensate. also known as drip leg
✔✔Drywall - ✔✔(or Gypsum Wallboard (GWB), sheet rock, plasterboard, wall board, or
gypsum) a manufactured panel made out of gypsum plaster and encased in a thin
cardboard or other material
✔✔Eaves - ✔✔the horizontal exterior roof overhang
✔✔Elbow - ✔✔the portion of the connector or chimney that turns or offsets the direction
of the chimney
✔✔Electronic Sniffer - ✔✔a device that emits a loud, piercing noise in the presence of
very small amounts of certain gases. Used in gas supply line and appliance leak
detection
✔✔Ethane - ✔✔a hydrocarbon compound found in natural gas
✔✔Excess Air - ✔✔air in the firebox or fire chamber of a solid fuel appliance that is not
used in combustion reactions (and exhausts through the venting system)
✔✔Excess Flow Valve (EFV) - ✔✔a gas valve designed to activate when the fuel gas
passing through it exceeds a prescribed flow rate
✔✔Explosion - ✔✔repaid burning with an improper rate of air and fuel; not under control
and with excessive pressure
