Worksheets9189 Phase 3 Combustion And Ventilation Revision Quizz
Total questions: 56
Worksheet time: 28mins
What are the three elements required for combustion to occur?
Fuel, water, and ignition
Fuel, oxygen, and ignition
Oxygen, water, and ignition
Fuel, carbon dioxide, and ignition
What is produced during complete combustion of hydrocarbons?
Carbon monoxide and water vapor
Carbon dioxide and water vapor
Oxygen and carbon monoxide
Hydrogen and carbon dioxide
What happens during incomplete combustion?
All carbon is turned into carbon dioxide
Carbon monoxide is produced due to insufficient oxygen
Only water vapor is produced
Complete combustion occurs
What type of flame is produced when combustion is complete?
A stable blue flame with a bright blue inner cone
A loose yellow flame
A red flame with a dark outer cone
A green flame with a bright outer cone
What is the main characteristic of a post-aerated flame?
It is smaller than a pre-aerated flame
It has a well-defined inner cone
It takes air for combustion from the surrounding atmosphere
It is used in domestic gas appliances
What does "pre-aerated" mean in the context of flames?
Air is drawn for combustion after the flame is lit
Air is entrained in the mixing tube before ignition
Air is mixed with gas after leaving the burner
Air is not involved in the combustion process
Which type of flame is most commonly used in domestic gas appliances?
Post-aerated flame
Pre-aerated flame
Neutral flame
Luminous flame
What is one of the causes of incomplete combustion in appliances?
Excessive oxygen supply
Lack of oxygen
High humidity
Low temperature
What does the term 'vitiated air' mean?
Air that is too dry
Air that is too cold
Air that has been made impure
Air that is too humid
What is a sign of incomplete combustion in an appliance?
Blue, steady flame
Yellow, floppy flame
Green, flickering flame
Red, stable flame
What is the effect of carbon monoxide in a room?
It has a strong smell
It is harmless
It can be lethal
It is visible
What is carbon monoxide?
A harmless gas with a sweet smell
A poisonous gas with no smell or taste
A gas that is beneficial for breathing
A gas with a metallic taste
What is the role of haemoglobin in carbon monoxide poisoning?
It enhances oxygen delivery to the brain
It blocks oxygen from reaching the brain
It neutralizes carbon monoxide
It increases blood flow to the brain
Which of the following is a symptom of carbon monoxide poisoning?
Increased appetite
Tension-type headache
Enhanced energy levels
Improved mental clarity
What is the purpose of a CO detector?
To increase carbon monoxide levels
To warn of the presence of carbon monoxide
To purify the air from carbon monoxide
To enhance the smell of carbon monoxide
Which sensor type changes color when it absorbs carbon monoxide?
Metal oxide semiconductor
Electrochemical sensor
Biometric sensor
Thermal sensor
What is the oxygen to fuel ratio required for the complete combustion of natural gas (CH₄)?
1:1
2:1
3:1
4:1
Which gas makes up the largest percentage of Earth's atmosphere?
Oxygen
Nitrogen
Argon
Carbon Dioxide
What are the two methods of supplying ventilation in buildings?
Natural and mechanical
Manual and automatic
Internal and external
Direct and indirect
What is the primary purpose of ventilation in buildings?
To increase humidity
To remove stale air and replace it with fresh air
To decrease temperature
To add carbon dioxide
What is the chemical equation for the complete combustion of methane (CH₄)?
CH₄ + O₂ → CO₂ + H₂O
2O₂ + CH₄ → CO₂ + 2H₂O
CH₄ + 2O₂ → CO₂ + 2H₂O
2CH₄ + O₂ → 2CO₂ + 2H₂O
What is the purpose of mechanical ventilation for combustion air?
To create a negative pressure zone
To ensure products of combustion do not back spill into the room
To increase the temperature of the room
To reduce noise from the boiler
Where should air vents NOT be placed?
In a fireplace opening
Close to the appliance
In intermediate spaces
In the wall cavity
Which British Standard specifies the installation and maintenance of gas fires and convector heaters?
BS 5871.3:2005
BS 5871.2:2005
BS 5440.2:2009
BS 5440 Part 2
What must be removed from ventilation openings to prevent blockage?
Fly screens
Air vents
Grilles
Draught excluders
What is the requirement for ventilation size according to the text?
It should be adjustable
It should be adequately sized
It should be smaller than the appliance
It should be larger than the appliance
What is the required ventilation for a flueless appliance?
10 cm²
5 cm²
No ventilation required
100 cm²
How much free air is required per kW of gas used for adventitious ventilation?
10 cm²
5 cm²
15 cm²
20 cm²
What is the minimum ventilation required for a fire/back boiler unit (BBU)?
50 cm²
75 cm²
100 cm²
150 cm²
How do you convert gross to net when calculating ventilation requirements?
Multiply by 1.11
Divide by 1.11
Add 1.11
Subtract 1.11
What is the primary purpose of vents located on an appliance compartment?
To provide air for complete combustion and appliance cooling
To block air from entering the compartment
To store additional appliances
To reduce noise from the appliance
What is an appliance compartment?
A storage area for gas appliances
An enclosure specifically designed or adapted to house one or more gas appliances
A venting system for gas appliances
A cooling system for gas appliances
What should be the clearance around an appliance situated in a compartment?
50 mm
75 mm
100 mm
25 mm
What is a potential risk if an appliance compartment is used for storage purposes?
Increased efficiency
Risk of fire and blocking of air vents
Improved air circulation
Reduced appliance noise
What is the formula to calculate the ventilation requirement for an open-flued appliance of 15 kW input installed in a compartment with vents facing externally?
Multiply the lower vent by 10 cm² and the higher vent by 5 cm²
Multiply the lower vent by 5 cm² and the higher vent by 10 cm²
Multiply both vents by 15 cm²
Multiply the lower vent by 20 cm² and the higher vent by 10 cm²
If the vents in the compartment face internally, what is the equation to calculate the ventilation requirement?
Input rating times 10 cm² for both vents
Input rating times 20 cm² for the lower vent and 10 cm² for the higher vent
Input rating times 5 cm² for the lower vent and 15 cm² for the higher vent
Input rating times 15 cm² for both vents
What is the requirement for internal vents when venting through more than one room?
Internal vents need to be 25% bigger than the external vent
Internal vents need to be 50% bigger than the external vent
Internal vents need to be the same size as the external vent
Internal vents need to be 75% bigger than the external vent
What is the maximum height above floor level for a low-level vent in an internal wall to reduce smoke spread during a fire?
450 mm
500 mm
400 mm
350 mm
Why do room-sealed appliances not require air for combustion?
They use internal air
They receive air from the outside
They do not need air
They use recycled air
What is the purpose of ventilation for room-sealed appliances installed in compartments?
For combustion
For cooling only
For heating
For noise reduction
What is the maximum air temperature allowed for cooling at 1.5 m above finished floor level (FFL)?
20 °C
25 °C
32 °C
40 °C
What is the minimum size for air vent openings?
2 mm
5 mm
10 mm
15 mm
Which material is NOT mentioned as a possible material for vents?
Terracotta
Plastic
Brass
Steel
What should an engineer verify about the air admitted through a vent?
The color of the vent
The temperature of the air
The free air volume
The material of the vent
What is the purpose of vents located on an appliance compartment?
To provide air for complete combustion and appliance cooling
To block air from entering the compartment
To increase the temperature inside the compartment
To reduce the noise of the appliance
What is the maximum length a duct connecting two air vents should be?
3 meters
5 meters
10 meters
1 meter
Why should hit-and-miss type vents never be used for gas appliances?
They can be blocked, reducing air passage
They are too expensive
They are too large
They are difficult to install
What should be done if a ducting run is unavoidable?
Keep it to a minimum of not more than 3 meters in length
Use flexible ducting
Increase the number of bends
Use smaller ducts
What is the maximum rated input limit for an instantaneous hot water heater in a room with a volume greater than 20 m³?
11 kW
5 kW
15 kW
20 kW
What is required for a domestic cooker located in a room with a volume between 5 and 10 m³?
100 cm² permanent vent and an openable window
50 cm² permanent vent and an openable window
Nil permanent vent and no openable window
Installation not permitted
What is the purpose of intumescent air vents?
To increase airflow in a room
To close in the event of a fire and stop the spread of smoke
To provide heating in cold environments
To allow more light into a room
What should be calculated from the greatest of the following when a room contains more than one gas appliance?
The aggregate maximum rated heat input of all flueless space heating appliances
The smallest maximum rated heat input of any appliance
The average heat input of all appliances
The total number of appliances
What is the correct size of vent required for a flueless water heater with a 28 kW input?
100 cm² plus an openable window
50 cm² plus an openable window
150 cm² plus an openable window
No vent is required
According to BS 5440 Part 2, how much extra free air space should be added to solve spillage problems with gas appliances?
25 cm²
50 cm²
75 cm²
100 cm²
What should be done when testing for spillage in areas where radon gas is a problem?
Turn off all extraction systems
Ensure all windows are closed
Turn on any extraction systems
Use a floor vent
What is the principle behind passive stack ventilation?
Forced air movement
Natural stack effect
Mechanical extraction
Heat exchange