NFI Core Review Class Exam 2026
Questions and Answers
4 Stages of combustion - Correct answer-1. Moisture evaporation
2. Release of combustible gases
3. Ignition of combustible gas
4. Char burning
The total energy produced by burning one pound of wood is
approximately____________ - Correct answer-8,600 BTUs
Catalytic converters can lower the ignition temperature of wood smoke to
approximately - Correct answer-500 degrees
The proper UL Standard for chimneys used to vent wood stoves is - Correct
answer-UL103HT
UL103HT - Correct answer-These requirements cover factory-built chimneys
intended for venting gas, liquid, and solid-fuel fired residential-type appliances and
building heating appliances
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, According to NFPA 211, the maximum horizontal run of a wood stove connector is
limited to ______________ percent of the vertical portion of the chimney above
the connector. - Correct answer-50%
According to NFPA 211, a manual damper installed in a wood stove connector pipe
cannot block more than ___________ percent of the connector when fully closed. -
Correct answer-80%
According to NFPA 211, the maximum permitted chimney flue area is ______
times the appliance flue collar area for exterior chimneys and ____ times the
appliance flue collar area for interior chimneys. - Correct answer-2 and 3
The maximum chimney offset angle permitted in the United States is __________
degrees (from vertical). - Correct answer-30 degrees
According to NFPA 211 and the IRC, a 3.5" brick wall with a 1" ventilated air
space provides a __________ percent clearance reduction - Correct answer-66%
According to NFPA 211 and the IRC, a 3.5" brick wall without ventilated air space
provides a __________ percent clearance reduction. - Correct answer-33%
According to NFPA 211 and the IRC, a 24 gauge sheet metal panel with a 1"
ventilated air space provides a __________ percent clearance reduction when used
as a ceiling protector. - Correct answer-50%
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
Questions and Answers
4 Stages of combustion - Correct answer-1. Moisture evaporation
2. Release of combustible gases
3. Ignition of combustible gas
4. Char burning
The total energy produced by burning one pound of wood is
approximately____________ - Correct answer-8,600 BTUs
Catalytic converters can lower the ignition temperature of wood smoke to
approximately - Correct answer-500 degrees
The proper UL Standard for chimneys used to vent wood stoves is - Correct
answer-UL103HT
UL103HT - Correct answer-These requirements cover factory-built chimneys
intended for venting gas, liquid, and solid-fuel fired residential-type appliances and
building heating appliances
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, According to NFPA 211, the maximum horizontal run of a wood stove connector is
limited to ______________ percent of the vertical portion of the chimney above
the connector. - Correct answer-50%
According to NFPA 211, a manual damper installed in a wood stove connector pipe
cannot block more than ___________ percent of the connector when fully closed. -
Correct answer-80%
According to NFPA 211, the maximum permitted chimney flue area is ______
times the appliance flue collar area for exterior chimneys and ____ times the
appliance flue collar area for interior chimneys. - Correct answer-2 and 3
The maximum chimney offset angle permitted in the United States is __________
degrees (from vertical). - Correct answer-30 degrees
According to NFPA 211 and the IRC, a 3.5" brick wall with a 1" ventilated air
space provides a __________ percent clearance reduction - Correct answer-66%
According to NFPA 211 and the IRC, a 3.5" brick wall without ventilated air space
provides a __________ percent clearance reduction. - Correct answer-33%
According to NFPA 211 and the IRC, a 24 gauge sheet metal panel with a 1"
ventilated air space provides a __________ percent clearance reduction when used
as a ceiling protector. - Correct answer-50%
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
