CFESA Gas Chapter 4
What is the difference between a vent and a flue? - answer A flue removes byproducts
from the combustion chamber. A vent removes products from the room to the outdoors.
What are the two primary functions of the flue? - answer Remove combustion
byproducts from the combustion chamber, and to create a draft to pull in secondary air.
How critical is the sizing of the flue? Why? - answer Very. Too small and it wil not
remove all the byproducts, if it is too large the vapors will start to condense.
Can a vent pipe be connected directly to the flue on a piece of gas equipment? -
answerNo
What is the function of a draft hood? - answerTo allow the flue to determine the draft
When should a draft hood be used? - answerAnytime a vent pipe is connected to a
piece of equipment
What is a downdraft? - answerAir entering down the vent pipe, usually caused by cold
outside temperatures or high winds
How can a downdraft create equipment problems? - answerIt can blow out pilots and
create problems getting a draft started in the combustion chamber.
What type of vent pipe should be used in commercial applications? - answerType B
double wall
Why is it necessary to use double wall vent pipe? - answerIt keeps the flue products
from condensing and provides an insulation barrier to prevents the hot flue gas from
starting a fire if something lays against it
What size vent pipe will be needed for a piece of equipment rated at 160,000 Btu, if it is
located 10 feet away from the roof opening, and in a room with a 10 foot ceiling? -
answer5 inch
What size vent pipes are needed for two ovens, each rated at eighty thousand Btu's, if
the roof is 10 feet high, and the flue connector rise is 2 feet on each of them? -
answerConnectors are 5 inches, common vent is 6 inch.
What kind of vents do most commercial kitchens have? - answerPower vents
What is the difference between a vent and a flue? - answer A flue removes byproducts
from the combustion chamber. A vent removes products from the room to the outdoors.
What are the two primary functions of the flue? - answer Remove combustion
byproducts from the combustion chamber, and to create a draft to pull in secondary air.
How critical is the sizing of the flue? Why? - answer Very. Too small and it wil not
remove all the byproducts, if it is too large the vapors will start to condense.
Can a vent pipe be connected directly to the flue on a piece of gas equipment? -
answerNo
What is the function of a draft hood? - answerTo allow the flue to determine the draft
When should a draft hood be used? - answerAnytime a vent pipe is connected to a
piece of equipment
What is a downdraft? - answerAir entering down the vent pipe, usually caused by cold
outside temperatures or high winds
How can a downdraft create equipment problems? - answerIt can blow out pilots and
create problems getting a draft started in the combustion chamber.
What type of vent pipe should be used in commercial applications? - answerType B
double wall
Why is it necessary to use double wall vent pipe? - answerIt keeps the flue products
from condensing and provides an insulation barrier to prevents the hot flue gas from
starting a fire if something lays against it
What size vent pipe will be needed for a piece of equipment rated at 160,000 Btu, if it is
located 10 feet away from the roof opening, and in a room with a 10 foot ceiling? -
answer5 inch
What size vent pipes are needed for two ovens, each rated at eighty thousand Btu's, if
the roof is 10 feet high, and the flue connector rise is 2 feet on each of them? -
answerConnectors are 5 inches, common vent is 6 inch.
What kind of vents do most commercial kitchens have? - answerPower vents
