Wood NFI Exam Questions and Answers
Graded A+
In the 80's particulate emissions for affected appliances were required to be limited
to: - Correct answer-4.1 grams/ hr(catalytic) & 7.5 grams/hr (noncatalytic)
The national regulations did not apply to appliances with: - Correct answer-- burn
rates grater 5kg/hr (11lbs of wood)
- air-to flue ratio > 35 to 1
- firebox > 20 cubic feet
- weight > 800kg or 1760lbs
-coal
-open wood burning
- solid fuel furnaces & boilers
- large industrial and commercial wood fired appliances
Tests showed that these regulations from the 80's showed that - Correct answer-
Emissions from certified appliances were 6kg/hr a reduction of 85%
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,May 2015 revised EPA regulations step 1 - Correct answer-- wood, pellet stoves =
4.5gram per hour limit
- Hydronic heaters have a 0.32 lbs per million BTU limit
- Forced air furnaces 0.93lbs per hour limit
May 15 2020 regulations for wood and pellet stoves - Correct answer-- 2 grams
per/hr crib wood
- 2.5 grams per/hr cordwood
Stages of solid fuel combustion - Correct answer-1. Moisture Evaporation > 212F
2. Release of combustible gases > 500F
3. Ignition and combustion of vapors and gases 540-1,225F
4. Char burning > 900F
How much water is produced for each pound of wood burned. - Correct answer-1/2
lb
At 100% combustion efficiency what byproducts would be produced - Correct
answer-- Water vapor
- carbon dioxide
- non combustible ashes
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, 4 factors that promote combustion efficiency - Correct answer-- fuel
- temperature
- turbulence
- time
Chimney connector reduced clearances with wall and ceiling protection:
3 1/2 " thick masonry wall without ventilated airspace:
Max clearance reduction Wall & Ceiling
Min allowed clearance Wall & Ceiling - Correct answer-Max Wall & Ceiling =
33% / —. Min Allowed clearance = 12" / —
Chimney connector reduced clearances with wall and ceiling protection:
24 gauge sheet metal over 1" glass fiber or mineral batts reinforced with wire, or
equivalent on rear face, with at least 1" ventilated airspace
Max clearance reduction Wall & Ceiling
Min allowed clearance Wall & Ceiling - Correct answer-Max Wall & Ceiling =
66% / 50% Min allowed = 6"/9"
Chimney connector reduced clearances with wall and ceiling protection:
3 1/2 " thick masonry wall with ventilated airspace:
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
Graded A+
In the 80's particulate emissions for affected appliances were required to be limited
to: - Correct answer-4.1 grams/ hr(catalytic) & 7.5 grams/hr (noncatalytic)
The national regulations did not apply to appliances with: - Correct answer-- burn
rates grater 5kg/hr (11lbs of wood)
- air-to flue ratio > 35 to 1
- firebox > 20 cubic feet
- weight > 800kg or 1760lbs
-coal
-open wood burning
- solid fuel furnaces & boilers
- large industrial and commercial wood fired appliances
Tests showed that these regulations from the 80's showed that - Correct answer-
Emissions from certified appliances were 6kg/hr a reduction of 85%
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,May 2015 revised EPA regulations step 1 - Correct answer-- wood, pellet stoves =
4.5gram per hour limit
- Hydronic heaters have a 0.32 lbs per million BTU limit
- Forced air furnaces 0.93lbs per hour limit
May 15 2020 regulations for wood and pellet stoves - Correct answer-- 2 grams
per/hr crib wood
- 2.5 grams per/hr cordwood
Stages of solid fuel combustion - Correct answer-1. Moisture Evaporation > 212F
2. Release of combustible gases > 500F
3. Ignition and combustion of vapors and gases 540-1,225F
4. Char burning > 900F
How much water is produced for each pound of wood burned. - Correct answer-1/2
lb
At 100% combustion efficiency what byproducts would be produced - Correct
answer-- Water vapor
- carbon dioxide
- non combustible ashes
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, 4 factors that promote combustion efficiency - Correct answer-- fuel
- temperature
- turbulence
- time
Chimney connector reduced clearances with wall and ceiling protection:
3 1/2 " thick masonry wall without ventilated airspace:
Max clearance reduction Wall & Ceiling
Min allowed clearance Wall & Ceiling - Correct answer-Max Wall & Ceiling =
33% / —. Min Allowed clearance = 12" / —
Chimney connector reduced clearances with wall and ceiling protection:
24 gauge sheet metal over 1" glass fiber or mineral batts reinforced with wire, or
equivalent on rear face, with at least 1" ventilated airspace
Max clearance reduction Wall & Ceiling
Min allowed clearance Wall & Ceiling - Correct answer-Max Wall & Ceiling =
66% / 50% Min allowed = 6"/9"
Chimney connector reduced clearances with wall and ceiling protection:
3 1/2 " thick masonry wall with ventilated airspace:
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
