NFPA 31 Questions and Graded Answers.
What do limit controls respond to? - Changes in temperature, pressure, fluid level, and
fluid flow
What is a fuel-burning appliance in which the flue gases are mixed with the medium -
Direct-Fired Appliance
Where is combustion air taken from in a direct vent appliance? - Outside the building
Where is combustion air taken from in a direct venting system? - Inside the Building
What is an appliance in which the flue gases are not mixed with the medium? - Indirect-
Fired Appliance
An unconfined space has a volume greater than or equal to ____ cubic feet per ______ Btu/hr of
all fuel-burning appliances installed therein - 50, 1000
The smaller dimension of rectangular ducts may not be less than _______ inches - 3
In an unconfined space where ventilation is needed, a permanent opening with a free opening of
at least 1 square inch per _________ Btu/hr of all appliances therein is required - 5,000
In a confined space where all air is taken from inside, permanent openings with free areas of at
least 1 square inch per _______ Btu/hr of all appliances therein are required - 1,000
In a confined space where all air is taken from outside and where vertical ventilation ducts are
used, free areas of at least 1 square inch per ______ Btu/hr of all appliances therein are required -
4,000
, In a confined space where all air is taken from outside and where horizontal ducts are used, free
areas of at least 1 square inch per ______ Btu/hr of all appliances therein are required -
2,000
In a confined space where ventilation air is taken from inside the building and combustion air is
taken from outside the building, permanent openings with a free area of at least 1 square inch per
_____ Btu/hr of all appliances therein - 5,000
Screens in louvers or grilles shall not be larger than ________ inch mesh - 1/4
If the free area of the design is not known, assume that wood louvers and grilles have __% free
area - 25
If the free area of the design is not known, assume that metal louvers and grilles have __% free
area - 75
A chimney shall be capable of producing the minimum draft required by the manufacturer (T/F)
- True
Are draft fans required? - Yes
Are manually operated dampers approved for use in venting systems? - No
Can a flue connector pass through a floor or ceiling? - No
The chimney connector shall maintain a pitch or rise of a least ____ inch - 1/4
Can an oil-burning appliance use the same chimney as an active fireplace? - No
What do limit controls respond to? - Changes in temperature, pressure, fluid level, and
fluid flow
What is a fuel-burning appliance in which the flue gases are mixed with the medium -
Direct-Fired Appliance
Where is combustion air taken from in a direct vent appliance? - Outside the building
Where is combustion air taken from in a direct venting system? - Inside the Building
What is an appliance in which the flue gases are not mixed with the medium? - Indirect-
Fired Appliance
An unconfined space has a volume greater than or equal to ____ cubic feet per ______ Btu/hr of
all fuel-burning appliances installed therein - 50, 1000
The smaller dimension of rectangular ducts may not be less than _______ inches - 3
In an unconfined space where ventilation is needed, a permanent opening with a free opening of
at least 1 square inch per _________ Btu/hr of all appliances therein is required - 5,000
In a confined space where all air is taken from inside, permanent openings with free areas of at
least 1 square inch per _______ Btu/hr of all appliances therein are required - 1,000
In a confined space where all air is taken from outside and where vertical ventilation ducts are
used, free areas of at least 1 square inch per ______ Btu/hr of all appliances therein are required -
4,000
, In a confined space where all air is taken from outside and where horizontal ducts are used, free
areas of at least 1 square inch per ______ Btu/hr of all appliances therein are required -
2,000
In a confined space where ventilation air is taken from inside the building and combustion air is
taken from outside the building, permanent openings with a free area of at least 1 square inch per
_____ Btu/hr of all appliances therein - 5,000
Screens in louvers or grilles shall not be larger than ________ inch mesh - 1/4
If the free area of the design is not known, assume that wood louvers and grilles have __% free
area - 25
If the free area of the design is not known, assume that metal louvers and grilles have __% free
area - 75
A chimney shall be capable of producing the minimum draft required by the manufacturer (T/F)
- True
Are draft fans required? - Yes
Are manually operated dampers approved for use in venting systems? - No
Can a flue connector pass through a floor or ceiling? - No
The chimney connector shall maintain a pitch or rise of a least ____ inch - 1/4
Can an oil-burning appliance use the same chimney as an active fireplace? - No
