WorksheetsChimney and Flue Systems Quiz
Total questions: 52
Worksheet time: 26mins
What are the two operating principles for any chimney or flue system?
Remove combustion products to the outside and draw in air for combustion.
Increase combustion temperature and decrease air pressure.
Reduce air intake and increase fuel consumption.
Lower combustion efficiency and increase smoke production.
What principle do chimneys and flue systems work on?
Hot gases rise, creating a pressure difference called 'up draught' via convection.
Cold air descends, creating a pressure difference called 'down draught' via conduction.
Hot gases fall, creating a pressure difference called 'down draught' via radiation.
Cold air rises, creating a pressure difference called 'up draught' via diffusion.
What is the primary purpose of a chimney or flue system?
To create an up draught to remove fumes
To provide structural support
To enhance building aesthetics
To increase heating efficiency
What are the two types of flue designs mentioned?
Natural draught and room sealed
Mechanical draught and open sealed
Natural draught and mechanical sealed
Room draught and open sealed
What is the primary function of an open flue in a heating appliance?
To cool the appliance
To supply water to the appliance
To remove products of combustion
To provide electricity to the appliance
How is the air for combustion supplied in an appliance with an open flue?
From a built-in air tank
From the room where the appliance is located
From a separate air compressor
From a closed air system
What are the two types of draughts that can be used in open flues?
Mechanical and electrical
Natural and forced
Manual and automatic
Hot and cold
What is the purpose of a fan in an open flue with forced draught?
To create a positive up draught by blowing the products of combustion up the flue.
To cool down the combustion products before they exit the flue.
To reduce the noise produced by the combustion process.
To filter out impurities from the combustion products.
What is the main advantage of room sealed (balanced) flues compared to open-flued appliances?
They are cheaper to install.
They draw air from inside the room.
They are safer because air does not enter the room.
They require less maintenance.
What are the two types of room sealed (balanced) flues?
Natural draught and fan assisted
Open-flued and closed-flued
Electric and gas
Manual and automatic
What is the purpose of the duct in a room sealed natural draught system?
To bring fresh air into the building
To evacuate products of combustion from the building
To circulate air within the building
To heat the building
Where are both the combustion air and products of combustion situated in a room sealed natural draught system?
Inside the building
In separate locations
In the same position outside the building
In the basement
How does a room sealed fan assisted flue work compared to a natural draught flue?
It uses a fan to force the process, ensuring safe evacuation.
It relies solely on natural air currents.
It does not require any fan or mechanical assistance.
It is larger and less flexible in positioning.
What is an advantage of a room sealed fan assisted flue over a natural draught flue?
It is much smaller and can be positioned in more places.
It is larger and requires more space.
It does not require any maintenance.
It is less efficient in evacuating products.
What is the effect of positioning the fan on the combustion product's outlet from the heat exchanger in a fan assisted boiler?
It creates a positive pressure (blowing).
It creates a negative pressure (sucking).
It increases the temperature of the boiler.
It reduces the efficiency of the boiler.
Where is the fan positioned in modern condensing boilers?
On the combustion product's outlet.
On the fresh air inlet.
Inside the heat exchanger.
Near the burner.
What does positioning the fan on the fresh air inlet create in a fan assisted boiler?
A negative pressure (sucking).
A positive pressure (blowing).
A vacuum.
A decrease in air flow.
What is the primary function of the primary flue in an open flue appliance?
To connect the draught diverter to the appliance
To prevent wind from entering the flue
To carry combustion products outside
To reduce carbon dioxide content
What is one of the functions of a draught diverter?
To increase the length of the flue
To prevent the loss of flame stability at the burner
To create 90° bends in the flue
To discharge gases to the atmosphere
What is a requirement for the secondary flue?
Must be at least 600 mm in length
Must contain 90° bends
Must be as straight as possible
Must be integrated with the appliance
What is the purpose of the terminal in a flue system?
To connect the primary and secondary flues
To help the flue gases discharge to the atmosphere
To create pressure fluctuations
To integrate the draught diverter
How does the design and installation of chimney and flue systems affect their function?
It affects the color of the chimney.
It affects the function of air intake and dispersion of combustion products.
It affects the temperature of the room.
It affects the noise level in the house.
What needs to be considered carefully when designing chimney and flue systems?
The color of the bricks.
The height of the building.
Several factors related to design and installation.
The type of paint used.
What is the recommended minimum angle for bends in chimney/flue systems to reduce frictional resistance?
30 degrees
45 degrees
60 degrees
90 degrees
What does the effective height of a chimney/flue system take into account?
Only the physical height
The color of the chimney
Frictional resistance encountered en route
The material of the chimney
What is necessary for a flue to work efficiently?
The temperature needs to rise quickly and remain constant.
The temperature should decrease gradually.
The flue gases should move slowly.
The flue should cool down rapidly.
What can happen when the flue is cool?
Flue gases move efficiently upwards.
Flue gases move slowly and can create condensation.
The chimney heats up fully in 2 minutes.
The temperature remains constant.
How long can it take for the chimney/flue to heat up fully?
1-2 minutes
3-4 minutes
5-10 minutes
15-20 minutes
What is the required velocity for safe evacuation of flue gases?
4 m/s
5 m/s
6 m/s
7 m/s
How should the opening of a terminal compare to the cross-sectional area of the flue?
Equal to the flue's area
Twice the flue's area
Half the flue's area
Three times the flue's area
Where should a terminal be located to ensure it is not a nuisance?
Inside a pressure zone
Outside a pressure zone
Near a window
Next to a door
What is the minimum flue height termination for a pitched roof with a net input of less than 70 kW?
At ridge, or 600 mm above or at least 1.5 m measured horizontally to the roof line
600 mm above the roof line
250 mm above the roof line
1000 mm above the roof line
For a flat roof with a parapet or external flue and a net input of less than 70 kW, what is the minimum flue height termination?
At ridge, or 600 mm above or at least 1.5 m measured horizontally to the roof line
600 mm above the roof line
250 mm above the roof line
1000 mm above the roof line
What is the minimum flue height termination for a flat roof without a parapet and providing an internal routed flue with a net input of less than 70 kW?
At ridge, or 600 mm above or at least 1.5 m measured horizontally to the roof line
600 mm above the roof line
250 mm above the roof line
1000 mm above the roof line
For a pitched or flat roof with a net input of more than 70 kW, what is the minimum flue height termination?
At ridge, or 600 mm above or at least 1.5 m measured horizontally to the roof line
600 mm above the roof line
250 mm above the roof line
1000 mm above the roof line
What are the types of rigid chimneys mentioned in the document?
Brick and masonry, Pre-cast blocks, Metallic flues
Wooden structures, Plastic pipes, Glass tubes
Stone pillars, Concrete slabs, Iron rods
Fiberglass, Aluminum sheets, Copper wires
What is another type of chimney construction mentioned besides rigid chimneys?
Flexible liners
Solid bricks
Wooden frames
Plastic tubes
What were rigid-brick and masonry chimneys (class 1 flue) designed for?
Fireplaces or appliances
Water drainage systems
Electrical wiring
Ventilation systems
What were the dimensions of chimneys installed prior to 1966?
9" x 9" or 225mm x 225mm
175mm round or 200mm²
300mm x 300mm
150mm x 150mm
What materials were used for chimneys after 1966?
Clay, pumice, or concrete
Wood and metal
Plastic and fiberglass
Glass and steel
Why were larger chimneys considered unsuitable for gas appliances?
They caused the velocity of the flue gases to slow down too much
They were too expensive to build
They were not aesthetically pleasing
They required more maintenance
What material are pre-cast flue blocks made from?
Wood
Metal
Concrete
Plastic
What is a common problem associated with pre-cast flue blocks?
They are too expensive
The 'pull' can be quite poor
They are difficult to install
They are not durable
Can all gas appliances be installed on pre-cast flue systems?
Yes, all can be installed
No, not all can be installed
Only electric appliances can be installed
Only small appliances can be installed
What should always be checked when dealing with pre-cast flue blocks?
The color of the blocks
The manufacturer's instructions
The weight of the blocks
The price of the blocks
What material are rigid-metallic flue systems typically made from?
Aluminum
High grade stainless steel
Copper
Plastic
What is the primary function of a twin wall in chimney construction?
To enhance aesthetic appeal
To guard against condensation and heat
To increase airflow
To reduce noise
Where can twin wall flue systems be used?
Only externally
Only internally
Both internally and externally
Only in industrial settings
For what appliances are some single wall flue systems suitable?
Refrigerators
Agas and stoves
Air conditioners
Washing machines
What is the role of a draught stabilizer in a chimney system?
To increase the temperature of the flue gases
To maintain a constant draught in the flue
To reduce the noise from the chimney
To filter out impurities from the flue gases
What is a key consideration when installing a flue system in a high-rise building?
The color of the flue
The weight of the flue materials
The wind pressure at higher altitudes
The type of fuel used in the appliance
What is the main purpose of a chimney cowl?
To prevent rain from entering the chimney
To enhance the aesthetic appearance of the chimney
To increase the height of the chimney
To reduce the temperature of the flue gases
