NFI HEARTH SPECIALIST CORE MAIN ANSWERS
AND QUESTIONS SET A+
✔✔
✔✔Solid Fuel - ✔✔wood, coal, and other similar organic materials in various forms
(e.g., chunk wood, pressed logs, wood pellets, wood chips, paper, processed coal,
coke, peat, charcoal)
✔✔Soot - ✔✔soft, black or brown velvety deposit of carbon particles inside appliances,
chimneys, and connectors
✔✔Sour Gas - ✔✔gas containing amounts of sulfur that prevent its use as a fuel unless
purified
✔✔Spark Arrester - ✔✔a noncombustible screen installed between the top of the
chimney and the underside of the chimney cap; prevents the escape of sparks and
burning materials from the chimney
✔✔Specific Gravity - ✔✔the weight of one substance compared to the weight of another
substance, both of equal volume
✔✔Spillage - ✔✔condiiton of flue gases failing to exit the venting system properly and
instead flowing out into the dwelling. Condition calls for immediate examination of
appliance and venting system and corrective action
✔✔Spillage Test - ✔✔method of detecting spillage. flame or smoke applied at draft
hood being blow in out (away from draft hood) indicates spillage problem that should be
remedied without delay
✔✔Steel Lined Fireplace - ✔✔masonry fireplace with prefabricated metal firebox that
has all the components of traditional fireplaces; may have double walls to provide
circulating air passage behind the fire chamber
, ✔✔Storm Collar - ✔✔metal plate or collar fastened and sealed with high temperature
sealant around the chimney just above the roof flashing. prevents water from entering
the space between the chimney and the roof flashing
✔✔Stud - ✔✔a 2x4 or 2x6 vertical framing member used to construct walls and
partitions
✔✔Span - ✔✔the clear distance that a framing member carries a load without support
between structural supports
✔✔Substrate - ✔✔catalytic combustor component that carries wash coat and catalyst.
must be inert, stable, porous material providing large surface area. almost exclusively
ceramic in solid fuel combustors
✔✔Sweet Gas - ✔✔gas in its natural state containing such small amounts of sulfur that
it can be used without purification processes
✔✔Tail Out - ✔✔end of the burning process in wood-burning appliances
✔✔Tee - ✔✔chimney connector or factory-built chimney component that provides a 90
degree turn in the venting system; has a removable plate at the bottom for inspection
and chimney cleaning convenience
✔✔Temperature Differential - ✔✔the difference in temperature between two areas, such
as inside and outside the chimney or house. (example if it is 90 degrees Fahrenheit
outside the house and 70 degrees Fahrenheit inside the house, the temperature
differential is 20 degrees Fahrenheit)
✔✔Termination - ✔✔components at the top of the chimneys
✔✔Therm - ✔✔unit of heating value equivalent to 100,000 BTUs
✔✔Thermocouple - ✔✔a device consisting of two pieces of dissimilar metals joined
together at one end (hot junction). when the hot junction is heated, the thermocouple
produces DC voltage across the other end. used to power thermoelectric gas valves
✔✔Thermopile - ✔✔a number of thermocouples connected in series to produce a
higher voltage than a single thermocouple
✔✔Thimble - ✔✔generally, a clay or metal sleeve through which chimney connector
passes to connect to a masonry chimney; construction depends on whether it is
intended for passage through combustible or noncombustible material
AND QUESTIONS SET A+
✔✔
✔✔Solid Fuel - ✔✔wood, coal, and other similar organic materials in various forms
(e.g., chunk wood, pressed logs, wood pellets, wood chips, paper, processed coal,
coke, peat, charcoal)
✔✔Soot - ✔✔soft, black or brown velvety deposit of carbon particles inside appliances,
chimneys, and connectors
✔✔Sour Gas - ✔✔gas containing amounts of sulfur that prevent its use as a fuel unless
purified
✔✔Spark Arrester - ✔✔a noncombustible screen installed between the top of the
chimney and the underside of the chimney cap; prevents the escape of sparks and
burning materials from the chimney
✔✔Specific Gravity - ✔✔the weight of one substance compared to the weight of another
substance, both of equal volume
✔✔Spillage - ✔✔condiiton of flue gases failing to exit the venting system properly and
instead flowing out into the dwelling. Condition calls for immediate examination of
appliance and venting system and corrective action
✔✔Spillage Test - ✔✔method of detecting spillage. flame or smoke applied at draft
hood being blow in out (away from draft hood) indicates spillage problem that should be
remedied without delay
✔✔Steel Lined Fireplace - ✔✔masonry fireplace with prefabricated metal firebox that
has all the components of traditional fireplaces; may have double walls to provide
circulating air passage behind the fire chamber
, ✔✔Storm Collar - ✔✔metal plate or collar fastened and sealed with high temperature
sealant around the chimney just above the roof flashing. prevents water from entering
the space between the chimney and the roof flashing
✔✔Stud - ✔✔a 2x4 or 2x6 vertical framing member used to construct walls and
partitions
✔✔Span - ✔✔the clear distance that a framing member carries a load without support
between structural supports
✔✔Substrate - ✔✔catalytic combustor component that carries wash coat and catalyst.
must be inert, stable, porous material providing large surface area. almost exclusively
ceramic in solid fuel combustors
✔✔Sweet Gas - ✔✔gas in its natural state containing such small amounts of sulfur that
it can be used without purification processes
✔✔Tail Out - ✔✔end of the burning process in wood-burning appliances
✔✔Tee - ✔✔chimney connector or factory-built chimney component that provides a 90
degree turn in the venting system; has a removable plate at the bottom for inspection
and chimney cleaning convenience
✔✔Temperature Differential - ✔✔the difference in temperature between two areas, such
as inside and outside the chimney or house. (example if it is 90 degrees Fahrenheit
outside the house and 70 degrees Fahrenheit inside the house, the temperature
differential is 20 degrees Fahrenheit)
✔✔Termination - ✔✔components at the top of the chimneys
✔✔Therm - ✔✔unit of heating value equivalent to 100,000 BTUs
✔✔Thermocouple - ✔✔a device consisting of two pieces of dissimilar metals joined
together at one end (hot junction). when the hot junction is heated, the thermocouple
produces DC voltage across the other end. used to power thermoelectric gas valves
✔✔Thermopile - ✔✔a number of thermocouples connected in series to produce a
higher voltage than a single thermocouple
✔✔Thimble - ✔✔generally, a clay or metal sleeve through which chimney connector
passes to connect to a masonry chimney; construction depends on whether it is
intended for passage through combustible or noncombustible material
