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WorksheetsUnderstanding Refrigeration and Heat Pumps
Total questions: 30
Worksheet time: 15mins
What is the main purpose of the vapour compression refrigeration cycle as defined in City & Guilds standards?
To heat up a room
To transfer heat from a low temperature area to a high temperature area
To create electricity
To freeze water
According to City & Guilds standards, which component in a refrigeration system increases the pressure and temperature of the refrigerant?
Condenser
Compressor
Evaporator
Expansion valve
What is the function of a heat pump in heating mode, as per City & Guilds guidance?
Cools the building
Transfers heat from outside to inside
Makes ice
Removes humidity
Which part of the refrigeration cycle absorbs latent heat from the space to be cooled, according to City & Guilds standards?
Condenser
Evaporator
Compressor
Expansion valve
Which refrigerant is commonly used in domestic refrigerators and is recognised by City & Guilds?
R134a
R22
R410A
R717
What is the main function of the condenser in a refrigeration system, as per City & Guilds standards?
To absorb heat
To reject heat to the surroundings
To compress refrigerant
To filter air
Which regulation controls the use and handling of fluorinated greenhouse gases in Great Britain, as required by City & Guilds?
The Clean Air Act
F-Gas Regulations
Water Act
Health and Safety Act
What is a key safety concern when working with refrigerants, according to City & Guilds standards?
High voltage
Toxicity, flammability, and risk of asphyxiation
Loud noise
Dust
Which type of oil is recommended for use with R134a refrigerant in City & Guilds approved systems?
Mineral oil
Polyolester (POE) oil
Vegetable oil
Silicone oil
What does a pressure-enthalpy diagram illustrate in accordance with City & Guilds standards?
The colour of refrigerant
The relationship between pressure and enthalpy throughout the refrigeration cycle
The size of the compressor
The cost of refrigerant
Which component reduces the pressure of the refrigerant before it enters the evaporator, as per City & Guilds standards?
Compressor
Expansion valve
Condenser
Filter drier
What is the main environmental concern with older refrigerants like R22, according to City & Guilds?
They are expensive
They deplete the ozone layer
They are noisy
They freeze easily
Which chart is used to measure and analyse humidity and temperature in air conditioning, as per City & Guilds standards?
Pressure-enthalpy diagram
Psychrometric chart
Bar chart
Pie chart
What is the boiling point of water at standard atmospheric pressure, as referenced in City & Guilds materials?
0∘ C
100∘ C
50∘ C
212∘ C
Which refrigerant is considered environmentally friendly and is recognised by City & Guilds?
R22
R290 (Propane)
R12
R134a
What should a qualified engineer do if a refrigerant leak is suspected, according to City & Guilds standards?
Ignore it
Report and repair it immediately following correct procedures
Open all windows
Add more refrigerant
Which system component removes moisture and contaminants from the refrigerant, as per City & Guilds standards?
Compressor
Filter drier
Condenser
Expansion valve
What is the main function of refrigerant oil in a compressor, according to City & Guilds?
To cool the air
To lubricate moving parts and reduce wear
To clean the system
To colour the refrigerant
Which maintenance task helps prevent system breakdowns, as recommended by City & Guilds?
Ignoring noises
Regular cleaning, inspection, and servicing
Overloading the system
Using the wrong refrigerant
What does the expansion valve do in a refrigeration system, as defined by City & Guilds?
Increases pressure
Decreases pressure and controls refrigerant flow into the evaporator
Heats the refrigerant
Filters the refrigerant
Which refrigerant is banned for new equipment in Great Britain due to environmental concerns, as per City & Guilds standards?
R134a
R22
R410A
R290
What is the main property of refrigerants that makes them suitable for cooling, according to City & Guilds?
High boiling point
Low boiling point
High viscosity
High density
Which diagram helps engineers understand the energy changes in a refrigeration cycle, as per City & Guilds standards?
Psychrometric chart
Pressure-enthalpy diagram
Bar chart
Pie chart
What is the main job of the evaporator in a heat pump, according to City & Guilds?
To reject heat outside
To absorb heat from the air or ground
To compress refrigerant
To filter water
Which refrigerant oil type is NOT suitable for use with R410A, as per City & Guilds standards?
Polyolester (POE) oil
Mineral oil
Alkylbenzene oil
Synthetic oil
What does the psychrometric chart help you find, as required by City & Guilds?
The price of refrigerant
The humidity and temperature of air
The size of the compressor
The colour of refrigerant
Which maintenance technique helps find leaks in a refrigeration system, as recommended by City & Guilds?
Listening for noises
Using leak detection equipment and methods
Adding more refrigerant
Ignoring the problem
What is the main reason for using different types of refrigerant oils, according to City & Guilds?
To change the colour of the refrigerant
To match the chemical properties of the refrigerant and system
To make the system louder
To increase the pressure
Which safety regulation must be followed when handling refrigerants in Great Britain, as per City & Guilds standards?
F-Gas Regulations
Water Act
Clean Air Act
Food Safety Act
What is the main function of a heat pump in cooling mode, according to City & Guilds?
To heat the building
To transfer heat from inside to outside
To make ice
To boil water
