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Worksheetsheat loss
Total questions: 65
Worksheet time: 42mins
Which British Standard covers the method for the calculation of design heating loads?
BS EN 12828:2003
BS EN 12831:2003
BS EN 14336:2004
BS EN 1264-1:1998
What is the measurement of the U-value?
w/m²K
kj/m°C
w/kg/K
J/m³/K
What is the correct formula to determine the heat loss from a space through air changes and ventilation?
m² x At x 1.33
m² x At x U-value
m³ x QTY x At 0.33
m³ x U-value x QTY x 3
What are the likely effects of oversizing a heating system?
Reduced energy usage, as systems produce enough heat quickly before shutting off for longer periods
Reduced life expectancy of heat emitters, which often overheat due to higher temperatures
Greater risk of burns/scalds, due to excess temperatures within the system and increased boiler combustion efficiency
Reduced energy efficiency, as boilers ‘hunt’, and greater initial outlay costs
What is the most suitable external design temperature for a house with normal sheltered exposure in England and Wales?
-1°C
-3°C
-4°C
-5°C
What is the correct formula to determine the heat loss through a surface such as a wall or window?
m² x Δt x 1.33
m² x Δt x U-value
m³ x QTY x Δt 0.33
m³ x U-value x QTY x 3
A radiator has a temperature of 70°C at the inlet and 50°C at the outlet. What is the MWT of the radiator?
20°C
40°C
50°C
60°C
You are trying to determine the correct size of an expansion vessel for a typical domestic central heating system. The system is installed in 22mm and 15mm copper. Which of the following methods could be used to give an approximate system volume?
2 litres per kW of the boiler
4 litres per kW of the boiler
6 litres per kW of the boiler
10 litres per kW of the boiler
What is the term given to the radiator within a central heating system which is the furthest from the heat source?
The content circuit
The shunt circuit
The hydraulic circuit
The index circuit
What is the formula used to determine the flow rate for a circuit?
kg/s = kW / 4.19 x Δt
W = kg x SHC x Δt
kW = 4.19 / kg x 1.33
Litres = kW x SHC / Δt
According to BSEN 14336:2004, what is the minimum test pressure and period for a water-based heating system?
At least 30% greater than the working pressure for a minimum of one hour
At least 30% greater than the working pressure for a minimum of two hours
At least 1.5 times the working pressure for three hours
At least 2 times the working pressure for one hour
What is the purpose of a hot flush of the central heating system?
To remove excess limescale deposits from the system
To ensure that the system flow rates can be achieved throughout the installation
To remove traces of the legionella bacteria from the system pipework
To remove excess jointing compounds, fluxes and oils from the system
Which component is initially used to balance the heat outputs at radiators?
Wheel head valves
TRVs
Lockshield valves
Pump speed controller
A radiator has stopped working and is completely cold. All the other radiators in the system are hot and no air is present in the cold radiator. What is the most likely problem?
Pin stuck within TRV
Sludge blocking parts of the radiator
Faulty pump
System needs balancing
Which of the following components can be used to check the charge pressure of an expansion vessel?
Pressure gauge at the boiler when the system is hot
Tyre pressure gauge when the system is hot and the vessel full
Pressure gauge on the boiler when the system is cold
Tyre pressure gauge with the vessel disconnected from the central heating system
A customer reports that she needs to top up the boiler regularly but cannot see any signs of leakage. All pipework from the combination boiler is visible and no signs of leaks are present. You have noticed signs of water at the pressure relief valve discharge pipe outlet. What is the most likely cause of the pressure loss?
Boiler pressure gauge is malfunctioning
Both check valves at the external filling loop are passing and the system is backflowing into the cold main
The cylinder coil has failed, leading to central heating water leaking into the secondary water
The expansion vessel has ruptured
You have been called to an old open vented system which has a pumped heating circuit and a gravity hot water circuit. The radiators are cold but the hot water is hot, despite the controller being switched to heating and hot water. No zone valves are installed. What is the most likely cause of the fault?
Failure of boiler thermostat
Failure of circulating pump
Failure of synchron motor
Failure of cylinder thermostat
U-values measures how quickly what happens?
Heat escapes through the structure
Light escapes through the structure
Sound escapes through the structure
Air escapes through the structure
The higher the U-value, the:
Lower the thermal resistance?
Higher the thermal resistance?
Lower the thermal value?
Higher the thermal value?
What is something that prevents heat, electricity, sound, light...to pass through it?
insulator
conduction
heat transfer
conductor
What is something that readily conducts heat, electricity, sound...
insulator
conduction
thermal equilibrium
conductor
The kind of heat transfer that travels through space in electromagnetic waves is ______________________.
insulation.
Radiation
Conduction
Convection
How does heat move?
from cold to hot
from hot to cold
In heat transfer, heat always flows from the _______________ substance to the _______________ substance.
Hotter to colder
Colder to hotter
Hotter to hotter
Colder to colder
Energy is transferred as heat between two objects of ___________ temperatures.
differing
same
What is a substance that does NOT conduct heat well?
Conductor
Insulator
Convector
Radiator
How can you prevent heat lost from the roof?
Loft insulation
Cavity wall Insulation
Double Glazing
Draft Proofing
How can you prevent heat lost from the wallls?
Loft insulation
Cavity wall Insulation
Double Glazing
Draft Proofing
The greater the temperature difference, the faster heat flows
no clue
false
true
Which object gains heat?
object A gains heat
object B gains heat
Which object losses heat?
object A losses heat
object B losses heat
Where is most of the heat lost from a house?
The walls
The windows
The roof
The floor
What is payback time?
How long it takes to make the amount of money back in energy bills savings that you spent.
The amount of time it takes to save up the money to pay for it.
How long it takes a bank to give you a loan.
How long you have to pay back the money you spent.
What are the three ways in which heat energy can be transferred?
Conduction, convection, and radiation
Reflection, absorption, and transmission
Evaporation, condensation, and sublimation
Expansion, contraction, and diffusion
Which of the following terms are associated with thermal insulation?
H-value, I-value, and J-value
K-value, U-value, and R-value
M-value, N-value, and O-value
P-value, Q-value, and S-value
What do U-values, K-values, and R-values measure in building materials?
Electrical conductivity
Heat transfer or thermal resistance
Acoustic insulation
Moisture permeability
What is the unit of thermal resistance?
m
m²K/W
W/mK
K/W
How is the U-value of a wall calculated?
By dividing the thickness of the wall by its thermal conductivity.
By multiplying the thermal resistance of each layer of the wall.
By adding the thermal resistances of each layer of the wall and then taking the reciprocal.
By dividing the thermal conductivity of the wall by its thickness.
What does a lower U-value indicate in terms of a building's thermal performance?
Poor insulation properties.
Higher energy consumption.
Better insulation properties.
Lower thermal resistance.
Which of the following materials would likely have the lowest U-value?
Brick
Glass
Insulation foam
Concrete
If a material has an R-value of 49, what is its U-factor
3.33
0.002
0.02
4.9
How do you determine the U-factor for a building assembly
Add U - factors and divide by 1
Divide 1 by the total of the R- values
Add U -factors of components
Add inverse R values together
What does R-value mean in insulation?
indicates the resistance to heat flow
indicates the resistance to cool air flow
indicates the room temperature
it is the value or degree that the house will stay
Instrument that can be used to measure how hot or cold an object is ...
dynamometer
anemometer
thermometer
Heat will continue to flow from hotter object to colder object until the temperature is ______________.
different
very different
the same
How many kinds of heat transfer are there?
1
2
3
4 or more
What is something that prevents heat, electricity, sound, light...to pass through it?
insulator
conduction
heat transfer
conductor
What is something that readily conducts heat, electricity, sound...
insulator
conduction
thermal equilibrium
conductor
___________________ is the type of heat transfer that occurs in fluids, such as warm air rising and cold air sinking; creating wind.
Convection
Conduction
Radiation
insulation.
What is the term given to the radiator within a central heating system which is the furthest from the heat source?
The content circuit
The shunt circuit
The hydraulic circuit
The index circuit
What is the formula used to determine the flow rate for a circuit?
kg/s = kW / 4.19 x Δt
W = kg x SHC x Δt
kW = 4.19 / kg x 1.33
Litres = kW x SHC / Δt
According to BSEN 14336:2004, what is the minimum test pressure and period for a water-based heating system?
At least 30% greater than the working pressure for a minimum of one hour
At least 30% greater than the working pressure for a minimum of two hours
At least 1.5 times the working pressure for three hours
At least 2 times the working pressure for one hour
Which object losses heat?
object A losses heat
object B losses heat
What is the typical flow temperature of an underfloor heating system laid in a screeded concrete floor
35–450C
40–450C
50–600C
70–800C
What size pipework is underfloor heating pipework
18mm outside diameter and a 14mm internal diameter,
22mm outside diameter and a 12mm internal diameter,
16mm outside diameter and a 10mm internal diameter,
16mm outside diameter and a 12mm internal diameter,
What temperature can Pex-Al-Pex pipe withstand
Pex-Al-Pex pipes can withstand up to 95ºC
Pex-Al-Pex pipes can withstand up to 85ºC
Pex-Al-Pex pipes can withstand up to 75ºC
Pex-Al-Pex pipes can withstand up to 100ºC
What spacings are normally used for underfloor heating
The pipes are usually installed 100–280mm apart across the floor of the room.
The pipes are usually installed 50–225mm apart across the floor of the room.
The pipes are usually installed 150–225mm apart across the floor of the room.
The pipes are usually installed 250–380mm apart across the floor of the room.
What is the minimum recommended height of the open vent pipe beyond the water level of the F&E cistern?
A minimum height of 500mm is normally suitable for fully pumped systems
A minimum height of 1450mm is normally suitable for fully pumped systems
A minimum height of 300mm is normally suitable for fully pumped systems
A minimum height of 450mm is normally suitable for fully pumped systems
What component within a sealed heating system produces the ‘neutral point’ within the system
The expansion vessel creates the neutral point within a sealed system.
The pressure reducing valve creates the neutral point within a sealed system.
The filling loop creates the neutral point within a sealed system.
The non return valvel creates the neutral point within a sealed system.
On an open vented system what is the correct orientation of the vent, cold feed and pump arrangements
Open vent Cold feed pump
Vent cold feed pump
Pump vent cold feed
Pump vent cold feed
In order to prevent corrosion and scale build-up in a central heating system, what can be added during initial filling
Vinegar
An inhibitor
Anti-freeze
Descaling solution
What can be incorporated in a heating system to remove magnetite
Scale reducer
Magnetic filters
Water softener
Electrolyte
What type of heating system can be split into zones that serve a cluster of houses and buildings?
District
Underfloor
Microbore
Thermosyphon
What is the purpose of a boiler interlock in a central heating system?
To increase water pressure
To prevent the boiler from cycling when there is no demand for heat
To reduce noise levels
To enhance air circulation
For dwellings with a total floor area greater than 150 m², what is the zoning requirement?
One space heating zone is sufficient.
No zoning is required.
At least two space heating zones, each with an independently controlled heating circuit.
Zoning is optional.
