CFESA GAS CH 4 QUESTIONS & ANSWERS
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? -
Answer -No
What is the function of a draft hood? - Answer -To allow the flue to determine the draft
When should a draft hood be used? - Answer -Anytime a vent pipe is connected to a
piece of equipment
What is a downdraft? - Answer -Air entering down the vent pipe, usually caused by cold
outside temperatures or high winds
How can a downdraft create equipment problems? - Answer -It 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? - Answer -Type B
double wall
Why is it necessary to use double wall vent pipe? - Answer -It 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? -
Answer -5 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? - Answer
-Connectors are 5 inches, common vent is 6 inch.
What kind of vents do most commercial kitchens have? - Answer -Power vents
When using a power vent hood, what caution must be used when it is designed and
installed? - Answer -Design a way to replace makeup air.
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? -
Answer -No
What is the function of a draft hood? - Answer -To allow the flue to determine the draft
When should a draft hood be used? - Answer -Anytime a vent pipe is connected to a
piece of equipment
What is a downdraft? - Answer -Air entering down the vent pipe, usually caused by cold
outside temperatures or high winds
How can a downdraft create equipment problems? - Answer -It 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? - Answer -Type B
double wall
Why is it necessary to use double wall vent pipe? - Answer -It 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? -
Answer -5 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? - Answer
-Connectors are 5 inches, common vent is 6 inch.
What kind of vents do most commercial kitchens have? - Answer -Power vents
When using a power vent hood, what caution must be used when it is designed and
installed? - Answer -Design a way to replace makeup air.
