Tesztek

F-Gas English Low GWP

Minden kérdés
HFC | Flammable | CO₂ | NH₃
Könnyű kérdések | Közepes nehézségű kérdések | Nehéz kérdések

1

Könnyű

What is the base unit of mass in the International System of Units (SI)?


kg
lb (pound)
N
t

2

Közepes

What process takes place in the condenser of a refrigeration system?


The refrigerant rejects only the heat generated in the compressor
The refrigerant absorbs heat from the surroundings and evaporates
Hot vapour discharged by the compressor is desuperheated, condensed, and the resulting liquid is slightly subcooled
The secondary fluid (glycol, water) condenses while the refrigerant evaporates

3

Közepes

What mainly determines the condensing temperature of an air-cooled condenser?


The compressor discharge temperature
The evaporating temperature
The ambient (inlet) air temperature
The superheat

4

Közepes

Why does heat flow from the condenser to the surroundings?


Because the pressure in the condenser is lower than ambient
Because HFC refrigerants attract heat from the surroundings
Because the condensing temperature is higher than the ambient temperature, and heat flows spontaneously from a warmer to a colder body (second law of thermodynamics)
Because the compressor pushes heat directly into the surroundings

5

Közepes

What should you mainly pay attention to when operating a condenser?


That the outlet air temperature is higher than the condensing temperature
The colour of the condenser casing
That the inlet air temperature is lower than the outlet air temperature
Its general condition and the cleanliness of the heat-exchange surfaces

6

Közepes

What criteria should be considered when selecting a suitable condenser?


Fan noise, connection diameters and colour
Only the size and number of fans
The required capacity of the condenser and the technical specifications declared by the manufacturer
Only own experience and the dimensions

7

Közepes

How do contaminants (dust, particulates, deposits) affect the performance and efficiency of heat exchange surfaces in condensers?


Contaminants do not significantly affect the efficiency and effectiveness of the heat exchange surfaces in condensers.
Contaminants restrict heat transfer (reducing the heat transfer coefficient) and cause an increase in condensing temperature and pressure, which in turn leads to a reduction in the condenser’s efficiency.
Contaminants increase the heat transfer area and reduce the condensing pressure.
Contaminants restrict heat transfer (reducing the heat transfer coefficient) and cause a reduction in condensing pressure.

8

Közepes

How does the capacity of an air-cooled condenser change when it becomes dirty?


It increases
It increases because the fan speed rises
It decreases
It remains unchanged

9

Közepes

What is the main consequence of heavy frost on an air-cooling evaporator?


Reduced heat transfer and airflow, resulting in a drop in cooling capacity and evaporating temperature
A rise in evaporating pressure
An increase in condenser subcooling
A rise in the cooled-air temperature with no effect on capacity

10

Közepes

What happens when the evaporation temperature drops?


The compressor’s cooling capacity decreases.
The discharge temperature decreases.
The condenser fan speed increases.
The compressor’s cooling capacity increases.

11

Közepes

When is natural (off-cycle, air) defrosting possible?


Only in freezer rooms below −18 °C
When the air passing through the cooler is above 0 °C
Only in coolers fitted with speed-controlled fans
Never – electric heaters must be used in every air cooler

12

Közepes

When does frost form on the surface of an air-cooling evaporator?


Only when the room air temperature falls below 0 °C
Always, in every air cooler
When the evaporator surface temperature is below 0 °C and below the dew point of the air
Only when the system runs continuously

13

Közepes

In extensive pipework systems, flash gas (secondary evaporation) in the liquid line can be prevented by…


…using smaller-diameter pipes
…additional subcooling of the liquid
…increasing the length of the liquid line
…insulating the discharge line between the compressor and the condenser

14

Közepes

How does hot gas defrosting of the evaporator work?


Heated vapour (hot gas) from the compressor is directed into the evaporator piping.
We switch on the gas heater directed at the evaporator.
We swap the outlet and inlet sides of the evaporator.
This involves reversing the direction of rotation of the compressor.

15

Közepes

What is the function of the evaporator in a refrigeration system?


It ensures that the refrigerant is superheated over the largest possible heat exchange surface area.
It evaporates the water flowing through the evaporator.
It transfers heat from the medium being cooled to the boiling refrigerant.
It cools the refrigerant.

16

Közepes

What condition must electric heaters for evaporator defrosting meet?


They must be located beneath the evaporator
They must be in direct contact with the refrigerant
They must have good thermal contact with the heat-exchange surface (e.g. inserted in the fin block)
Heat from the heaters must be carried by the running fans

17

Közepes

Refrigerant distributor:


ensures even distribution of the refrigerant to the individual sections of the condenser.
ensures an even distribution of the refrigerant to the individual sections of the evaporator.
ensures the even distribution of the refrigerant discharged by compressors connected in parallel.
acts as a buffer for the refrigerant in the event that the pressure upstream of the expansion valve is exceeded.

18

Közepes

What defrosting methods are used for air coolers?


Electric only – other methods are not permitted in refrigeration
Only by switching off the fans with the compressor running
Electric, hot gas, water spray and natural (at positive temperatures)
Natural only – other methods are ineffective and uneconomic

19

Közepes

The boiling point of a liquid rises when the pressure above the liquid…


…falls
…remains constant
…rises
…varies depending on the ambient temperature

20

Közepes

MOP in thermostatic expansion valves stands for:


minimum flow opening.
maximum operating pressure.
self-cleaning of the valve in the event of moisture in the refrigerant freezing.
maximum pressure switch protection.

21

Közepes

The function of a thermostatic expansion valve (TEV) is:


to adjust the evaporating pressure in the condenser
to maintain a constant compressor suction pressure
to meter refrigerant into the evaporator according to the superheat of the vapour leaving the evaporator
to maintain a constant condensing pressure

22

Közepes

What type of compressor motor can be used with a capillary tube?


A high-starting-torque motor must be used
An electronically commutated motor
A low-speed motor
A low-starting-torque motor (pressures equalise during standstill)

23

Közepes

What does a thermostatic expansion valve control?


The condensing pressure
The discharge temperature
The mass flow of refrigerant fed into the evaporator
The temperature in the cold room

24

Könnyű

The refrigerant absorbs heat when…


…it evaporates
…it condenses
…it is subcooled
…it freezes

25

Közepes

What does the manufacturer state as the factory setting of a thermostatic expansion valve?


the superheat value during valve operation.
the degree to which the valve is filled with refrigerant liquid.
the degree of refrigerant expansion.
the static superheat of the valve.

26

Közepes

Where is a new or repaired system with an expansion valve and liquid receiver charged?


In the liquid phase on the high-pressure side, with the compressor stopped
Anywhere – the charging point does not matter
Through the capillary tube outlet during normal system operation
In the liquid phase into the compressor suction, with the compressor running

27

Közepes

What does a thermostatic or electronic expansion valve control?


Subcooling, by adjusting condensing pressure
The amount of refrigerant fed to the evaporator according to superheat
The compressor speed
The evaporating pressure – closing below the set point

28

Közepes

What does the MOP function of thermostatic expansion valves mean?


The valve prevents motor overheating by injecting liquid into the compressor
The valve maintains a constant condensing pressure
The valve limits the maximum evaporating (suction) pressure, protecting the compressor motor from overload, e.g. after defrost
The valve limits subcooling

29

Közepes

The lower the liquid temperature upstream of the expansion valve, (at the same mass flow)…


…the lower qo and the lower Qo
…the higher the specific refrigerating effect qo [kJ/kg] and the higher the cooling capacity Qo
…the lower qo and the lower energy efficiency
…the lower qo, with Qo unchanged

30

Közepes

How should the MOP point of an expansion valve be selected relative to the highest normal evaporating temperature?


About 7 K lower than that temperature
A few kelvin higher (approximately 7 K)
Higher by approx. 20 K
Freely – the MOP value is irrelevant

31

Közepes

What is the function of the suction pressure regulator?


It prevents a drop in suction pressure and, if necessary, shuts down the refrigeration system.
It maintains the evaporation pressure at a constant level.
It limits the suction pressure and protects the compressor from excessively high suction pressure.
To maintain the suction pressure at the highest possible level.

32

Közepes

What is the function of the valve regulating water flow through the condenser?


To maintain the condensing pressure at the highest possible level.
To maintain the water temperature at the highest level.
To maintain the condensing pressure at the lowest possible level.
To maintain the condensing pressure at a constant level.

33

Közepes

The use of a refrigerant distributor requires a thermostatic expansion valve ...


... with an adsorption-type sensor filling.
... with external pressure equalisation.
... with a MOP function.
... with internal pressure equalisation.

34

Közepes

What properties should good insulation materials have?


High thermal conductivity
An antistatic coating
Low thermal conductivity (and low water absorption, vapour tightness)
The ability to absorb large amounts of moisture

35

Közepes

When is refrigerant vapour superheated?


When the evaporating temperature is lower than the ambient temperature
When its temperature is higher than the saturation temperature corresponding to its pressure
When the pressure on the discharge side is higher than on the suction side
When the compressor motor temperature rises excessively

36

Közepes

How can you check whether the liquid refrigerant is reaching the expansion valve without vapour bubbles?


We check using a pressure gauge fitted on the discharge side of the compressor.
We check this using a sight glass.
We check using a liquid pressure gauge.
We are unable to check this.

37

Közepes

Where does the liquid line run?


Between the evaporator and the compressor
Between the compressor and the condenser
From the condenser (liquid receiver) to the expansion valve
Between the evaporator and the suction-line heat exchanger

38

Közepes

What is the function of the liquid receiver in a refrigeration system?


To further subcool the condensed refrigerant
To collect liquid refrigerant and excess oil
To act as a reserve when the required charge is unknown
To store refrigerant and compensate for changes in the circulating charge as the heat load varies

39

Közepes

What is the purpose of the liquid receiver during service work?


It further subcools the refrigerant before the expansion valve
It collects excess oil circulating in the system
It allows pump-down and temporary storage of the refrigerant
It is a reserve when the installer does not know the required charge

40

Közepes

Where should the liquid receiver be installed?


It should be installed downstream of the condenser, upstream of the expansion valve.
It should be fitted between the compressor and the condenser.
It should be fitted after the evaporator.
It should be fitted just before the compressor.

41

Közepes

What is the function of the suction pressure regulator fitted to the suction pipe when the compressor starts up?


It regulates the evaporation pressure.
It opens when the suction pressure upstream of the compressor drops.
It regulates the condensing pressure.
It closes when the suction pressure upstream of the compressor drops.

42

Közepes

The use of microchannel heat exchangers, compared with conventional heat exchangers made of copper tubes and fins, results in:


An increase in the amount of refrigerant in the system and an increase in condensing pressure.
There is no effect whatsoever on either the amount of refrigerant or energy efficiency.
A reduction in the system’s energy efficiency.
A reduction in refrigerant charge and, typically, higher energy efficiency.

43

Közepes

Which refrigerants belong to the HFC group?


R134a, R404A, R507A, R410A.
R22, R401A.
R134a, R32, R22, R507A, R290.
R11, R12, R502.

44

Közepes

Which refrigerants belong to the HFO group?


R134a, R290.
R1234yf, R1234ze(E).
R134a, R404A.
R22, R12.

45

Közepes

What are the characteristics of R410A refrigerant compared to R407C refrigerant?


The saturation pressure of R407C is 150% higher than that of R410A.
The saturation pressure of R410A refrigerant is higher than that of R407C.
The saturation pressure of R407C refrigerant is much higher than that of R410A.
The saturation pressure of both refrigerants is roughly the same.

46

Közepes

What does the TEWI indicator define?


The ability of the ozone layer to recover
The global warming potential of a gas relative to CO₂ over a 100-year horizon
The impact of a refrigerant on the ozone layer
Total Equivalent Warming Impact: the sum of direct emissions (leakage and refrigerant losses at disposal) and indirect emissions (CO₂ from generating the energy consumed by the equipment) over its lifetime

47

Közepes

What are the characteristics of R452A compared with R404A?


It is a non-flammable (A1) HFC/HFO blend with properties similar to R404A and a GWP about 45% lower
The temperature glide of R452A is half that of R404A
It is a flammable and toxic single-component HFC
Both are azeotropic and have no temperature glide

48

Közepes

What distinguishes R1234yf from R134a?


It is mildly flammable (class A2L), whereas R134a is non-flammable (A1)
Higher toxicity
A higher normal boiling point
A higher critical temperature

49

Közepes

How does CO₂ (R744) compare with R134a?


Unlike R134a, it is an azeotropic mixture
Its temperature glide is 7 K greater than that of R134a
It has identical properties and is a drop-in replacement for R134a
It has a lower critical temperature, much higher operating pressures and a much higher volumetric cooling capacity (smaller compressors and pipes)

50

Közepes

Which of the following is NOT a fluorinated greenhouse gas?


Carbon dioxide (CO₂).
Sulphur hexafluoride (SF6).
Perfluorocarbons (PFCs).
Hydrofluorocarbons (HFCs).

51

Közepes

What is the greenhouse effect?


Dust in the atmosphere reflects sunlight, lowering the average surface temperature
Clouds reflect ultraviolet radiation, which makes the air near the surface warmer
Greenhouse gases absorb and re-emit the Earth's infrared radiation, warming the lower atmosphere
Chlorine compounds destroy stratospheric ozone, increasing UV radiation at the surface

52

Könnyű

What does the GWP indicator mean?


The ability of a substance to restore the ozone layer
The annual rise in mean air temperature caused by the emission of 1 kg of the gas
Ozone depletion potential
Global Warming Potential: the climate warming impact of 1 kg of a gas compared with 1 kg of CO₂ (GWP = 1) over a defined time horizon, usually 100 years

53

Közepes

How do refrigeration systems contribute to the greenhouse effect?


Only through the heat rejected by the condenser
Only through CO₂ given off by the compressor motor
Through oil emitted into the atmosphere from the condenser and filter
Indirectly (through energy consumption) and directly (through emissions of refrigerant into the atmosphere)

54

Közepes

What is the greenhouse effect?


The formation of a layer that traps only heat from fuel combustion in aircraft
The filtering of solar radiation by the atmosphere
The absorption of solar radiation by the Earth's surface
The trapping of heat in the Earth's atmosphere, which hinders the radiation of heat into space

55

Közepes

Which EU regulation is currently the primary piece of legislation governing the use of fluorinated greenhouse gases (F-gases) in the European Union?


Directive 2009/125/EC
Regulation (EU) No 517/2014
Regulation (EU) 2015/1188
Regulation (EU) 2024/573

56

Közepes

What is the main objective of Regulation (EU) 2024/573?


To reduce taxes on refrigeration equipment
Standardising metal recycling standards
To facilitate the import of electrical appliances
Prevention of F-gas emissions and the achievement of the EU’s climate targets

57

Közepes

What are the ecodesign obligations of manufacturers of refrigerating appliances?


Only implementing an ISO 9001 quality management system
Meeting implementing regulations (e.g. 2019/2019, 2015/1095): efficiency, spare parts, reparability
Only using energy labels under Regulation (EU) 2024/573
Only declaring F-gas quantities under Regulation (EU) No 517/2014

58

Közepes

What is the main objective of EU ecodesign legislation (Directive 2009/125/EC, now Regulation (EU) 2024/1781 – ESPR)?


To standardise the appearance of products in the EU
To increase sales of electrical appliances in the EU
To reduce the negative environmental impact of products by improving energy efficiency, durability and recyclability
To facilitate imports from outside the EU

59

Közepes

What is the function of a ball valve in a refrigeration system?


It measures the moisture content of the refrigerant
It prevents excessive pressure build-up in the system
It regulates the temperature of the refrigerant
Enables the refrigerant flow to be completely shut off

60

Könnyű

What is the main function of a safety valve?


Discharges refrigerant when the set pressure is exceeded
It controls the oil level in the compressor
It monitors the moisture content of the refrigerant
Prevents the evaporator from freezing

61

Közepes

How do certain gases contribute to the greenhouse effect?


They heat the air through chemical reactions with atmospheric oxygen and nitrogen
They trap thermal radiation that the Earth would otherwise emit into space
They limit UV radiation reaching the Earth's surface, changing the heat balance
They deplete the ozone layer, so more solar radiation reaches the surface

62

Közepes

What is the purpose of a sight glass (with moisture indicator)?


Visual assessment of the refrigerant condition in the liquid line (bubbles) and of system moisture
Regulating compressor pressure
Emergency shut-off of flow
Measuring condenser temperature

63

Közepes

What is the function of the temperature regulator in a refrigeration system?


To maintain a constant pressure in the compressor
Controls the operation of the compressor and valves to maintain the set temperature
It drains excess refrigerant into the receiver
It restricts oil flow

64

Nehéz

What is the role of a suction liquid separator (also in systems with flammable or toxic refrigerants)?


It separates liquid from oil
It is used only to measure moisture
It prevents liquid refrigerant from entering the compressor
It heats the refrigerant before the evaporator

65

Nehéz

What is the function of an oil separator in systems using flammable or toxic refrigerants?


It prevents liquid from entering the compressor
They are used solely to measure the moisture content of the refrigerant
Heats the refrigerant before it enters the evaporator
Separates oil from the refrigerant and facilitates the return of oil to the compressor

66

Közepes

What is the purpose of oil level regulators in a refrigeration system?


They control the pressure in the condenser
Maintains the correct oil level in the compressor
They control the evaporator temperature
They drain off excess refrigerant

67

Közepes

What is the function of the liquid receiver in relation to system tightness?


It keeps the whole system at constant pressure regardless of load
It regulates the oil returning to the compressor
It controls the evaporating temperature by varying the circulating charge
It stores refrigerant; checking its liquid level helps detect charge loss

68

Közepes

What is the role of a gauge manifold with thermometers (temperature probes)?


It monitors refrigerant moisture content
It relieves pressure if it is exceeded
It controls oil level
It measures pressures and temperatures to determine superheat and subcooling and thus assess the system charge (indirect leak check)

69

Közepes

What is the role of defrost controls?


They protect the evaporator from icing and damage that could lead to leaks
They control compressor discharge pressure during defrost
They monitor the moisture content of the refrigerant
They drain excess oil from the evaporator to the receiver

70

Könnyű

What is the unit of pressure in the International System of Units (SI)?


Pa (pascal)
psi (pound per square inch)
atm (standard atmosphere)
bar (gauge)

71

Közepes

Where can the lists of fluorinated greenhouse gases be found?


In the national Act on ozone-depleting substances and certain fluorinated greenhouse gases
In a regulation of the Minister of Economy on the list of fluorinated greenhouse gases
In Annexes I–III to Regulation (EU) 2024/573 of the European Parliament and of the Council
In the Vienna Convention for the Protection of the Ozone Layer

72

Közepes

Where can the lists of ozone-depleting substances be found?


In Annexes I and II to Regulation (EU) 2024/590 of the European Parliament and of the Council
In a regulation of the Minister of the Environment on the list of controlled substances
In the Vienna Convention for the Protection of the Ozone Layer
In the national Act on ozone-depleting substances and certain fluorinated greenhouse gases

73

Nehéz

Why are PFAS formed by the decomposition of certain F-gases (e.g. TFA from HFOs) problematic?


They are readily biodegradable
They are very persistent, accumulate in the environment (e.g. water) and may be toxic
They are climate- and environment-neutral
They cause rapid cooling of the atmosphere

74

Közepes

Where and by when must entities obliged under the Polish Act of 15 May 2015 submit annual reports on ODS and F-gases?


By 31 January, in the Central Register of Operators (CRO)
By the end of the calendar year, on a form at a regional office of the Office of Technical Inspection (UDT)
By 28 February of the following year, electronically via the Reports Database (BDS) run at the Institute of Industrial Chemistry (ICHP)
By 31 March, electronically to the Ministry of Climate and Environment

75

Közepes

Which installation measure has a major impact on compressor energy efficiency?


Installing a suction line smaller than recommended
Charging extra refrigerant 'as a reserve' above the nameplate value
Proper evacuation and dehydration of the system (removing air and moisture)
Omitting the filter-drier to reduce flow resistance

76

Közepes

How does regular oil-level monitoring affect compressor operation?


It ensures proper lubrication and limits wear and energy losses
It allows any type of oil to be topped up
It allows the crankcase heater to be omitted
It increases cooling capacity above nominal

77

Könnyű

How do system leaks affect compressor energy efficiency?


Refrigerant loss reduces capacity and increases energy use (longer run times, higher superheat)
They improve efficiency because condensing pressure drops
They affect only safety, not energy use
No effect as long as the system still cools

78

Közepes

Regulation (EU) 2024/590 relates to:


Ozone-depleting substances
Alternative refrigerants replacing fluorinated greenhouse gases
Conditions for F-gas certification of companies recovering and reclaiming refrigerants
Health and safety during refrigerant recovery

79

Közepes

What is the significance of proper suction and discharge pressure control?


It keeps the compressor at optimal conditions (suction pressure as high and condensing pressure as low as permissible)
Pressures do not affect energy use
The lowest possible suction pressure is best
The highest possible condensing pressure is best

80

Közepes

Which maintenance measure reduces compressor energy consumption?


Raising the high-pressure switch setting
Replacing the filter-drier when the pressure drop or moisture indicator shows it is necessary
Permanently disabling the crankcase heater
Topping up refrigerant at every service visit

81

Közepes

How does air (non-condensable gas) in the system affect operation?


It raises the condensing pressure and reduces efficiency
It improves condenser heat transfer
It lowers the condensing pressure
It only affects the sight-glass indication

82

Közepes

What role do controls play in compressor efficiency?


They provide safety only, with no energy effect
They enable optimised operation and lower energy use (e.g. floating head pressure, capacity matching)
They matter only in NH₃ systems
They increase the circulating refrigerant charge

83

Közepes

How does suction superheat at the compressor affect efficiency?


The higher the superheat, the higher the efficiency
Zero suction superheat is optimal
Excessive superheat reduces efficiency and raises the discharge temperature
Superheat has no effect

84

Közepes

How does correct system layout affect efficiency?


It affects only appearance
It doesn't matter
Longer pipes improve subcooling and always increase efficiency
It shortens pipe runs and limits pressure drops and energy losses

85

Közepes

How important is suction pipe insulation?


It limits heat gain and excessive superheat, improving efficiency
It has no effect
It increases energy consumption
It is needed only for appearance

86

Közepes

Which measure most improves condenser energy efficiency?


Regular cleaning of heat-exchange surfaces
Raising the condensing pressure set point
Increasing the refrigerant charge
Reducing fan speed to the minimum

87

Könnyű

How does a dirty condenser affect the operation of the refrigeration system?


It lowers the condensing pressure
Causes an increase in pressure and energy consumption by the compressor
It has no effect
It improves efficiency

88

Könnyű

Why is adequate airflow through an air-cooled condenser important?


The lower the airflow, the lower the condensing pressure
It ensures effective heat rejection and low condensing pressure
It affects only noise
It doesn't matter

89

Közepes

Which refrigerants damage the ozone layer?


All natural refrigerants
All refrigerants containing carbon in their molecules
All refrigerants containing fluorine and hydrogen in their molecules
All refrigerants containing chlorine or bromine in their molecules

90

Könnyű

How does the presence of limescale in a water-cooled condenser affect performance?


It has no effect
Impairs heat exchange and increases energy consumption
It improves heat transfer
It lowers the condensation temperature

91

Közepes

How does correct condensing pressure control affect efficiency?


It keeps the lowest pressure that still ensures proper expansion-valve feed, reducing energy use
It always increases energy use
It has no effect
It is best to keep a constant high condensing pressure all year

92

Könnyű

How do condenser leaks affect energy efficiency?


They lower the temperature
They improve efficiency
Causes refrigerant loss and a drop in efficiency
Have no effect

93

Könnyű

How important is the correct positioning of an air-cooled condenser?


It should be housed in a small room
It should be installed in a well-ventilated area with unobstructed airflow
It should be close to heat sources
It doesn’t matter

94

Könnyű

How does hot air recirculation affect the condenser?


It has no effect
It improves efficiency
It reduces the pressure
Impairs cooling and increases energy consumption

95

Közepes

How does insulation of heating and DHW pipework affect the efficiency of a heat pump system?


It impairs cooling
It reduces energy losses and improves overall system efficiency
It doesn't matter
It increases pressure

96

Közepes

Which measure most improves the energy efficiency of an air-cooling evaporator?


Restricting the airflow through the evaporator
Raising the condensing temperature by a few kelvin
Defrosting at the right time and keeping the fins clean
Increasing the refrigerant charge above nominal

97

Könnyű

How does evaporator icing affect the system’s operation?


It lowers the condensation temperature
It improves cooling performance
Impairs heat exchange and increases energy consumption
It has no effect

98

Könnyű

How does dirt on the evaporator surface affect its performance?


It improves efficiency
It has no effect
It reduces the pressure
Impairs heat exchange and increases energy consumption

99

Könnyű

What maintenance task is crucial for the evaporator?


Increasing the refrigerant charge
Reduced airflow
Lack of maintenance
Regular cleaning and defrosting

100

Közepes

What does a Certificate A2 for natural persons (Implementing Regulation (EU) 2024/2215) authorise?


Only leak checks that do not entail breaking into the refrigerant circuit
All activities (leak checks, installation, repair, maintenance, servicing, decommissioning, recovery) involving F-gases and hydrocarbons in equipment containing less than 3 kg, or less than 6 kg in labelled hermetically sealed systems
Only recovery of F-gases from equipment containing less than 3 kg (or 6 kg in hermetically sealed systems)
All activities involving equipment using CO₂ (R744)

101

Könnyű

How does superheat at the evaporator outlet affect efficiency?


It has no effect
It only causes a temperature drop
It always improves performance
Excessive superheat reduces energy efficiency

102

Könnyű

How do leaks in the evaporator affect efficiency?


Have no effect
Increase capacity
Improves performance
These cause refrigerant loss and a drop in efficiency

103

Könnyű

How important is correct expansion valve adjustment?


It increases energy consumption
It doesn’t matter
Ensures optimal evaporator charge and improves efficiency
Causes leaks

104

Könnyű

How does inadequate insulation of suction (or secondary-coolant) pipes affect evaporator performance?


It causes cooling losses and increased energy use
It lowers the condensing temperature
It improves efficiency
It has no effect

105

Könnyű

How does correct TEV adjustment affect system energy efficiency?


It ensures optimal superheat and improves efficiency
It causes leaks
It increases energy use
It has no effect

106

Könnyű

What happens if the superheat set by the TEV is too high?


The refrigerant charge will increase
It has no effect
Cooling efficiency will improve
Efficiency will drop because the evaporator is not being fully utilised

107

Közepes

How does too low superheat setting on the TEV affect performance?


It reduces refrigerant flow
It increases operational safety
It has no effect
It may lead to improved efficiency, but it increases the risk of the compressor becoming flooded with liquid

108

Könnyű

How do contaminants in the system affect the operation of the TEV?


They can cause it to become blocked and reduce efficiency
Have no effect
They lower the temperature
They improve its performance

109

Könnyű

What role does the filter-drier play in terms of system efficiency?


It lowers the temperature
It increases the amount of refrigerant
Removes moisture and contaminants, improving the system’s efficiency
It doesn’t matter

110

Könnyű

How does proper insulation of components (e.g. pipes near the TEV) affect the system?


It increases energy consumption
It doesn’t matter
It causes leaks
Prevents unwanted heat gains and improves efficiency

111

Közepes

What is the scope of Regulation (EU) 2024/573?


Only requirements for periodic leak checks of refrigeration equipment
Design requirements and conformity assessment for pressure equipment
Health and safety requirements for brazing and welding on refrigeration installations
Limiting emissions, use and marketing of F-gases, HFC phase-down, certification and reporting

112

Könnyű

How important is it to check the operation of the condensing pressure control valve in the system?


Ensures operation within the optimum pressure range and reduces energy losses
It increases energy consumption
It causes a significant rise in temperature
It has no effect

113

Könnyű

How does the correct selection of a TEV affect energy efficiency?


It lowers the temperature
Ensures the system is matched to its capacity and operates optimally
It increases the amount of refrigerant
It doesn’t matter

114

Közepes

How can you tell that the system has been overcharged with refrigerant?


It cannot be checked, because the sight glass is not intended for this
Even under a very small heat load, frost forms on the suction line
The compressor runs at a lower load and the suction pressure drops
Under normal operating conditions the condensing pressure and subcooling rise markedly because excess liquid floods the condenser and reduces its active surface

115

Közepes

Before charging the unit with refrigerant, it is essential to…


…carry out a trial start-up
…fill in the unit's data sheet
…check the compressor suction and discharge connections
…carry out a tightness test (and evacuate the system)

116

Közepes

What information must appear on the label of equipment containing F-gases?


The weight and capacity of the pipework and the colour code of the casing paint
That it contains an F-gas, its designation, quantity in kg and t CO₂ eq, and GWP
The manufacturer's logo, the unit weight and year of manufacture from the rating plate
Only the trade name of the refrigerant and the unit's serial number

117

Könnyű

What is the base unit of temperature according to the International System of Units (Système International d’Unités)?


°F
K
°R
°C

118

Közepes

Which set of information best reflects the content of the equipment records required by Regulation (EU) 2024/573?


The owner, installer and service technician of the unit
The make and model of the unit
Only the date of installation and the installer's name
Operator details, equipment details, type and quantity of refrigerant, and information on servicing and repairs

119

Nehéz

Which statement about installing Schrader valves is correct?


When brazing the valve body, the core must be removed, then refitted and tightened to the correct torque
All Schrader cores are suitable for all refrigerants
Hydrocarbons leak through Schrader valves
Schrader valves must not be used in R744 systems

120

Nehéz

How does an undercharge affect the high-pressure side (without discharge pressure control)?


Discharge pressure higher, subcooling higher
Discharge pressure higher, subcooling lower
Discharge (condensing) pressure and subcooling will both be lower
Discharge pressure lower, subcooling higher

121

Nehéz

What is the benefit of adding helium as a tracer gas to nitrogen in a pressure test?


It reacts with refrigerant residues, producing a visible colour change
It has a higher pressure than pure nitrogen in the same cylinder
Its small atoms pass easily through leaks and are detected
It has a distinctive odour that helps locate the leak

122

Közepes

Who is responsible for keeping the equipment records?


The person responsible for risk assessment.
There is no such obligation.
The equipment maintenance technician.
The operator of the unit or system.

123

Nehéz

What can be the effect of a relief valve lifting repeatedly?


The valve may not reseat tightly and its set (opening) pressure may decrease
The valve no longer opens
The set pressure increases
The valve stays fully open permanently

124

Közepes

Where are oil traps installed on the suction line?


At the inlet to every component of the refrigeration system
Immediately before the compressor suction connection
Before the safety valve on the suction side
At the bottom of vertical suction risers with upward flow

125

Nehéz

What is the relationship between the pressure (p) and temperature (T) of nitrogen at the start (1) and end (2) of a tightness test (p absolute, T in kelvin)?


p₂ = (p₁ × T₂)/T₁
p₂ = (p₁ × T₁)/T₂
p₂ = T₁/(p₁ × T₂)
p₂ = T₂/(p₁ × T₁)

126

Közepes

Which symptoms with the compressor running indicate a refrigerant leak (undercharge)?


Sight glass full of liquid and rising oil level in the crankcase
Low suction pressure, high superheat and negligible subcooling
Rising condensing and suction pressures with no superheat
Rising liquid level in the receiver and increasing subcooling

127

Közepes

Which components of a refrigeration system are potential leak points subject to leak checks?


Only high-pressure-side components
Hermetic compressors, liquid receivers and liquid separators
Only suction-side components
Joints, valves (including stems), seals (including those on replaceable filters and driers), parts subject to vibration and connections to safety and measuring devices

128

Közepes

What pressure is used for the pressure tightness test of an installation?


The pressure specified in EN 378-2 or by the manufacturer, not exceeding the maximum allowable pressure of the system (PS)
A pressure chosen by the technician based on experience
Always 30 bar
A pressure equal to the maximum pressure measured during operation

129

Közepes

At which points of the unit must the leak check be carried out?


Only at connections of measuring instruments
Only on discharge-side components
Only on compressor shut-off valves, solenoid valves and filters
At all points where there is a potential risk of refrigerant leakage

130

Közepes

When can a unit be considered tight after a pressure test?


When gas bubbles appear after immersion in water
When it has been checked with a fixed electronic detector
When the pressure drop does not exceed 0.1 bar regardless of the test duration
When the pressure remains constant during the test (allowing for temperature-related changes); any unexplained pressure drop requires the leak to be located

131

Közepes

Which legal act currently sets out the obligation to check stationary refrigeration equipment containing F-gases for leaks, and how often this must be done?


Commission Regulation (EC) No 1516/2007
Regulation (EU) 2024/573
Implementing Regulation (EU) 2024/2215
Regulation (EU) No 517/2014

132

Nehéz

Which parts of a refrigeration system should be given particular attention during a leak check?


Only condenser connections, because the refrigerant is liquid there
Compressor and receiver connections, because the pressure is highest there
Only compressor connections, because they are the only parts subject to vibration
Joints, valves incl. stems, seals, parts subject to vibration, connections to safety devices

133

Könnyű

What is the superheat of refrigerant vapour?


The amount of heat required to evaporate a liquid
The difference between the condensing temperature and the ambient temperature
The difference between the actual vapour temperature and the saturation temperature corresponding to its pressure (expressed in K)
The difference between the saturation temperature and the actual liquid temperature in the liquid line

134

Nehéz

Leak checks can be carried out using various methods. Which pair is correct?


Material quality control methods and electronic methods
Direct and indirect methods
Physical and chemical methods
Methods with and without quality control of supplies

135

Nehéz

To whom can leak checks of stationary refrigeration equipment containing F-gases be entrusted?


A person who has carried out such checks before
An employee appointed by the owner of the installation
A natural person holding a certificate covering leak checks (A1, A2 within its charge limit, or E)
Any leak-testing specialist

136

Nehéz

What conditions must be met to use UV dye for leak checking?


It is sufficient that introducing dye into the circuit is technically feasible
It is sufficient to have a UV lamp, dye and safety goggles
Manufacturer approval of the method and a certificate covering breaking into the circuit
A UDT authorisation for pressure testing is required

137

Nehéz

Which leak-checking methods are considered direct methods?


Vacuum test and foam solution
Pressure-change measurement and immersion in water
1. gas detection devices (portable or fixed leak detection system), 2. UV detection fluid or dye, 3. bubble/foam solutions
Nitrogen with tracer gas and pressure measurement

138

Nehéz

What do indirect leak-checking methods involve?


Ultrasonic measurement
Leak detection with an electronic detector
Leak detection with UV dye
A visual and manual check and analysis of parameters: pressure, temperature, compressor current, liquid levels and recharge volume

139

Közepes

How should the pressure be increased during a pressure tightness test?


In one step, by fully opening the nitrogen cylinder valve
As quickly as possible
Gradually, in stages, checking for leaks at each level until the test pressure is reached
In any way

140

Közepes

What electronic equipment should be used for leak checking?


Detectors suited to the refrigerant in the system, with appropriate sensitivity, checked periodically
Only devices with an 'ion pump' sensor
Only detectors with an infrared sensor
Only hot-cathode devices

141

Közepes

What documentation should be checked before starting a leak check?


The equipment records – especially recurring problems and previous leaks
The operator's fixed-asset inventory ledger
Attendance sheets of the plant-room staff for the year
Only the installation invoice and the first start-up report

142

Közepes

What information must be recorded in the leak check report?


Date, number and location of leaks, how they were repaired, technician details and signature
The date, a general note about the leak and the operator's signature
Only the number of leaks found and the date of the check
The method used, the time spent on site and the cost of repair

143

Közepes

What pressure should be used for the pressure tightness test?


A pressure not exceeding the maximum allowable pressure of the system (PS)
Always 10–12 bar
Any pressure, at the technician's discretion
Always 2–3 bar

144

Közepes

What is the temperature glide of a refrigerant?


The temperature drop of the refrigerant across the expansion valve
In zeotropic mixtures, the difference between the temperatures at the start and end of a phase change (boiling or condensation) at constant pressure
A property of single-component refrigerants, for which one saturation temperature corresponds to a given pressure
The temperature rise of the vapour in the compressor

145

Nehéz

What does a vacuum (decay) test involve?


After isolating the pump, you check whether the system pressure rises
The pump is restarted every time the system pressure rises
With the pump running, you watch the vacuum gauge reading
The pump runs continuously to hold the required vacuum for the test

146

Nehéz

How often should leak tests be carried out on equipment containing 1.5 kg of R404A refrigerant (5.9 tonnes of CO₂ equivalent)?


Only when servicing the unit.
At least once every 12 months.
On initial commissioning.
Once every six months.

147

Nehéz

How often should leak tests be carried out on equipment containing 7 kg of R404A refrigerant (27.45 tonnes of CO₂ equivalent)?


On initial commissioning.
At least once every 12 months.
Only when servicing the unit.
Once every six months.

148

Közepes

In which equipment is a leakage detection system required?


Equipment with ≥ 500 t CO₂ eq of Annex I F-gases (or ≥ 100 kg of Annex II Section 1 gases)
Equipment with 30 kg or more of F-gases, regardless of their GWP
Equipment with 5 t CO₂ eq or more of F-gases, regardless of equipment type
Equipment with 50 t CO₂ eq or more of F-gases, regardless of equipment type

149

Nehéz

Under Regulation (EU) 2024/573, a leakage detection system is mandatory when:


the equipment contains a flammable refrigerant in any quantity
the F-gas charge of the refrigeration equipment is 500 t CO₂ eq or more
the charge is 100 kg or more of ozone-depleting substances
the equipment operates in an enclosed space

150

Nehéz

Which leak-checking method may NOT be used by a holder of a Category E certificate?


Leak checking with a fluorescent dye introduced into the circuit
Visual inspection
Measurement with a handheld electronic detector
Checking with a foaming solution

151

Közepes

What should you check before using a portable electronic leak detector?


That it holds a valid UDT inspection certificate
That it suits the refrigerant and has been checked as the manufacturer requires
That it has been zeroed close to the suspected leak point
That it has an infrared sensor, as only this type is permitted

152

Közepes

Which certificate types (A1, A2, B, C, D, E) authorise leak checks of equipment containing F-gases?


All except D
Only E
A1, A2 and E
Only A1 and A2

153

Nehéz

Within what timeframe must a leak test be carried out on a stationary refrigeration system after a leak has been repaired, in accordance with EU Regulation 2024/573 on F-gases?


Immediately after the repair.
Between 24 hours and 1 month after the repair.
At the next periodic inspection.
At any time.

154

Nehéz

How often must refrigeration equipment containing ≥500 t CO₂ eq of F-gases be checked if (contrary to Article 6) no leakage detection system is installed?


Every 3 months
Every 6 months
Every month
Every 12 months

155

Közepes

Why is it advisable to subcool the liquid refrigerant?


To allow a condenser with a smaller heat-exchange surface to be used
To allow a smaller expansion valve to be used
To lower the evaporating temperature in the evaporator
To ensure that liquid free of vapour bubbles enters the expansion valve

156

Közepes

What must be done after repairing a leak in the refrigeration unit of a refrigerated trailer?


Update the equipment records and carry out a leak check (it may be done directly after repair)
Visually inspect only the bolted and brazed joints near the repair
Charge an alternative refrigerant, start up and measure the parameters
Issue the invoice and leave the leak check to the next periodic service

157

Közepes

Recovery of fluorinated greenhouse gases means:


The final decommissioning and withdrawal from service or use of a product or piece of equipment containing fluorinated greenhouse gases.
The collection and storage of fluorinated greenhouse gases from containers, products and equipment during maintenance or servicing or prior to their disposal.
The reprocessing of fluorinated greenhouse gases to achieve their specified standard properties.
The reuse of fluorinated greenhouse gases following a basic purification process.

158

Közepes

Who is authorised to recover refrigerant from stationary refrigeration equipment containing F-gases?


The owner of the installation
A natural person holding a certificate of the relevant type (A1; A2. or D within their charge limit)
The operator
The administrator of the operator's account in the register

159

Közepes

How must recovered refrigerants be stored?


In any pressure vessel that has some form of approval
In a labelled recovery cylinder with a dual valve and a valid inspection
In any used refrigerant cylinder, provided it is leak-tight
In a disposable (non-refillable) cylinder that held the same refrigerant

160

Közepes

When should the recovery of fluorinated greenhouse gases be carried out:


Before the final disposal of equipment and, where applicable, during its servicing and maintenance.
Before each leak test of the equipment.
Only prior to the final disposal of equipment.
Always during servicing and maintenance of equipment.

161

Közepes

What should be done if recovered refrigerant is contaminated (e.g. with acid, air or moisture)?


Add a special contaminant neutraliser
Clean the mixture yourself using a filter-drier
Pass it through a particle filter and reuse it
Hand it over to a specialised, authorised company for reclamation or destruction

162

Közepes

What should be done if different refrigerants have been mixed in a storage cylinder?


Add a special refrigerant to the mixture
Separate the mixture into its components yourself
Pass it through a filter-drier and reuse it
Hand the mixture over to an authorised company – as a rule for destruction

163

Közepes

How does push-pull refrigerant recovery work?


Nitrogen is injected into the system, pushing the refrigerant into the atmosphere
Refrigerant is drawn alternately from the suction and discharge sides of the compressor
The recovery unit draws vapour from the system and condenses it in the cylinder
The recovery unit draws vapour from the recovery cylinder and pushes it into the system; the pressure difference forces liquid refrigerant out of the system into the cylinder

164

Közepes

What are the options for managing waste refrigerant?


Recovery, disposal
Disposal, storage
Recycling, reclamation, destruction
Reclamation, recovery

165

Közepes

Which management option restores recovered refrigerant to a quality equivalent to virgin product, so that it can be used by any undertaking?


Recycling
Destruction
Storage
Reclamation

166

Közepes

The lower the evaporating temperature, …


…the greater the density of the suction vapour and the lower the refrigerant mass flow rate
…the greater the density of the suction vapour and the greater the refrigerant mass flow rate
…the lower the density of the suction vapour and the greater the cooling capacity of the compressor
…the lower the density of the suction vapour and the lower the refrigerant mass flow rate

167

Közepes

How must transportable pressure vessels (e.g. refrigerant cylinders) be marked?


With the manufacturer's logo and date of manufacture
The marking is optional
Among other things: the number of the design and testing standard, marks of the approving country and the inspection body, the date of the initial inspection, and the manufacturer's and operational marks
Only with weight and capacity marks

168

Közepes

The recovery of refrigerants does not require the use of:


An electronic leak detector.
Scales with a measurement range suitable for the size of the cylinder being filled.
Hoses with shut-off valves.
A refrigerant recovery station.

169

Közepes

What functions does the compressor perform in a refrigeration system?


The compressor compresses ambient air and increases the pressure of the refrigerant.
The compressor creates a vacuum on the suction side of the system
The compressor draws in refrigerant vapour from the evaporator, compresses it, and then forces it into the condenser, raising the pressure to the required condensing pressure.
The compressor condenses the refrigerant.

170

Könnyű

What is the compression ratio of a compressor?


The ratio of suction pressure to discharge pressure (po/pc)
The ratio of absolute discharge pressure to absolute suction pressure (pc/po)
The ratio of discharge pressure to the effective capacity of the compressor (p/Vk)
The amount of refrigerant compressed per cycle relative to heat capacity

171

Közepes

What is compressor flooding (liquid slugging)?


Flooding of the compressor by rainwater
Excess oil in the condenser
Liquid refrigerant or oil entering the compression chamber
A large amount of liquid refrigerant in a flooded evaporator, which is a normal operating condition

172

Közepes

Within what range is the compressor motor speed typically controlled using a frequency inverter?


From approximately 10% to 90% of nominal capacity
By a maximum of 10%
Approximately 30 to 75 Hz, corresponding to about 60–150% of nominal capacity (depending on the compressor manufacturer)
Speed control does not change the cooling capacity

173

Könnyű

What is the theoretical displacement (swept volume flow) of a compressor?


A value expressed by the coefficient of performance (COP)
The volume of refrigerant flowing in one piston cycle under actual operating conditions
The volume of a single cylinder in cm³
The volume of vapour drawn in per unit of time, determined by the compressor's geometry and speed (stated by the manufacturer, e.g. in m³/h)

174

Közepes

Why is it essential to observe the correct phase sequence for scroll compressors and screw compressors?


Because this type of compressor has difficulty starting up if the phase sequence is changed.
Because these types of compressors are sensitive to voltage drops.
Because the motor speed would decrease, and consequently the compressor’s capacity.
Because changing the phase sequence would reverse the direction of rotation of the compressor rotors, which could result in damage to the compressors.

175

Közepes

What compression ratio should each stage of a two-stage vapour-compression system have (rule of thumb)?


Greater than 18
Greater than 10
Equal to 1
Less than approximately 8

176

Közepes

Why is a shaft seal necessary in open-type compressors?


To protect the crankshaft bearing
Only to prevent oil leakage
To ensure the bearing remains lubricated
To prevent air from entering and refrigerant from leaking out of the compressor

177

Közepes

How can you check whether the liquid refrigerant is sufficiently subcooled?


Check whether the liquid distributor upstream of the evaporator feels warm
Compare the liquid-line temperature with the saturation temperature at the measured condensing pressure
Check whether the whole evaporator surface is covered with an even layer of frost
Check by touch whether the condenser outlet is noticeably colder than ambient

178

Közepes

Why is the compressor crankcase heated?


To dehydrate the oil
To limit refrigerant migration into, and dissolution in, the oil during standstill
To keep the lubricating oil liquid
To increase dissolution of refrigerant in the oil and improve its viscosity

179

Könnyű

What is the clearance (dead) volume of a reciprocating compressor?


The space between the underside of the piston and the crankcase cover
The space between the side of the piston and the cylinder
The volume between the valve plate and the piston crown at top dead centre
The volume between the valve plate and the piston at bottom dead centre

180

Közepes

What are compressor packs (racks)?


Sets of compressors connected in any configuration
Several compressors connected in parallel on a common frame with common suction and discharge headers
Units with two-stage compressors
Several air-cooled condensers

181

Közepes

What is the main advantage of multi-compressor packs?


A smaller refrigerant charge than a single-compressor system
Stepwise capacity matching to demand, plus redundancy
No need for compressor controls and safety devices
Low purchase cost and easy installation without special controls

182

Közepes

What is meant by the operating envelope (application range) of a compressor?


A range determined only by the evaporating temperature
The capacity, refrigerant type and dimensions of the compressor
The permissible range of evaporating and condensing temperatures (to, tk), or the corresponding pressures, within which the compressor may operate
A range determined by the evaporating temperature at a given ambient temperature

183

Közepes

What are the basic functions of oil in a compressor?


Lubricating bearings and sliding surfaces, removing heat, and sealing clearances (e.g. between piston and cylinder, or rotors)
Increasing the cooling capacity of the refrigerant
Absorbing moisture from the refrigerant
Sealing leaks that develop in the installation

184

Közepes

What are the most effective ways of controlling compressor cooling capacity?


Partially covering the evaporator
Pressure control valves
Changing the displacement: varying the rotational speed or unloading cylinders
An expansion valve

185

Közepes

What does hot-gas bypass capacity control involve?


High-pressure liquid is injected into the suction to increase capacity
Bypass is not used for capacity control
Part of the hot discharge gas is passed through a bypass valve to the suction side (or evaporator inlet), reducing the effective capacity
The compressor speed is varied

186

Közepes

What is the fundamental difference between hermetic and semi-hermetic compressors?


The semi-hermetic casing is bolted (can be opened); the hermetic one is welded
The semi-hermetic compressor has no motor inside the casing
Both can be dismantled; they differ only in cooling capacity
Semi-hermetic compressors run more quietly as a complete unit

187

Közepes

How does a scroll compressor work?


It uses two screws to compress the refrigerant.
A scroll compressor is also known as a turbo compressor.
It is a positive-displacement compressor in which compression results from the interaction of a fixed and an orbiting scroll.
It is a type of piston-type device.

188

Közepes

What physical process takes place in the evaporator?


The refrigerant is subcooled as a liquid
The refrigerant condenses
The liquid refrigerant evaporates, absorbing heat, and the vapour is slightly superheated at the outlet
The secondary fluid (glycol, water) evaporates while the refrigerant condenses

189

Közepes

What is the purpose of compressor capacity control?


To ensure compressor lubrication
To match capacity to the condensing temperature
To match the cooling capacity to the current demand
To increase the condensing pressure

190

Közepes

Why is inverter speed control advantageous for refrigeration compressors?


It can be used with any compressor to ensure lubrication
It enables continuous, smooth control of cooling capacity
It increases compressor capacity above nominal at any frequency
Reducing the speed improves oil return to the compressor

191

Közepes

Does the suction gas temperature affect the cooling capacity of the compressor?


Yes, but only if the suction gas is deeply cooled
Yes – higher temperature lowers vapour density, mass flow and capacity
Yes, but only in reciprocating compressors, not scroll
No – capacity depends only on the compressor displacement

192

Közepes

In the case of compressor units fitted with an oil level control system, is it necessary to install the compressors at the same height?


Yes.
No.
Only scroll compressors.
Only screw compressors.

193

Közepes

What functions does a compressor powered by the vehicle’s engine perform in a transport refrigeration system?


This compressor creates a vacuum on the suction side of the system whilst the vehicle’s engine is switched off.
This compressor condenses the refrigerant whilst the vehicle is in motion.
The compressor compresses ambient air and increases the pressure of the refrigerant.
This compressor draws in refrigerant vapour from the evaporator, compresses it and then forces it into the condenser whilst the vehicle’s engine is running.

194

Közepes

Which media most commonly absorb heat from the refrigerant in the condenser?


Only a water–glycol mixture
Air and CO₂
Air or water
Ammonia

195

Közepes

What is the function of the condenser in refrigeration systems?


Releasing only the heat from the compressor into the surroundings
Releasing to the environment the heat absorbed in the evaporator and the heat added during compression
Releasing only the heat absorbed in the evaporator into the surroundings
Absorption of heat rejected in the regenerative heat exchanger

196

Közepes

If the refrigerant temperature on the high-pressure side is above its critical temperature, condensation…


…does not depend on temperature
…always occurs regardless of temperature
…occurs provided a special condenser is used
…does not occur

197

Közepes

How is liquid subcooling usually achieved in a refrigeration system?


By dissolving the refrigerant in oil
With an additional heat exchanger using liquid nitrogen
With hot high-pressure vapour
In the final section of the condenser (or in an additional subcooler)

198

Közepes

What is the purpose of condenser fan speed control?


To disperse refrigerant in the event of a leak
To reduce energy efficiency
Only to protect against exceeding the maximum condensing pressure
To keep the condensing pressure at the correct level

199

Közepes

Which international agreement introduced the global phase-down of HFC production and consumption?


The Kigali Amendment to the Montreal Protocol
The Vienna Convention for the Protection of the Ozone Layer
The Kyoto Protocol
The Paris Agreement

200

Közepes

Which international treaty governs the phase-out of ozone-depleting substances (CFCs, HCFCs)?


The Stockholm Convention
The Montreal Protocol
The Paris Agreement
The UN Framework Convention on Climate Change (UNFCCC)

201

Nehéz

What is the basis of the GWP values in Regulation (EU) 2024/573?


AR4 for all substances
Each Member State sets its own GWP values
AR6 for all substances
For HFCs (Annex I) – mainly the IPCC Fourth Assessment Report (AR4); for HFOs and non-fluorinated substances (Annexes II and VI) – the Sixth Assessment Report (AR6)

202

Nehéz

An air conditioner (not hermetically sealed) contains 2.5 kg of R410A (GWP 2088). How often must it be checked for leaks?


Every 6 months
No checks required (below 3 kg)
At least every 12 months (5.22 t CO₂ eq)
Every 3 months

203

Nehéz

When is labelled hermetically sealed equipment containing HFCs (Annex I) exempt from leak checks?


When it contains less than 5 t CO₂ eq
Always, regardless of charge
Never – hermetically sealed equipment is always checked
When it contains less than 10 t CO₂ eq, and in residential buildings also when it contains less than 3 kg of F-gases

204

Nehéz

Is a chiller containing 50 kg of R1234ze(E) subject to leak checks under Regulation (EU) 2024/573?


No – HFOs are not subject to leak checks
Yes – every 12 months, because its GWP is low
No – the threshold is 5 t CO₂ eq and 50 kg of R1234ze is below 1 t CO₂ eq
Yes – at least every 6 months (every 12 months with a leakage detection system)

205

Nehéz

In 2026, may an existing refrigeration installation using R404A (GWP 3922) be topped up with virgin refrigerant?


Yes – bans apply only to new equipment
No – only reclaimed or recycled R404A is allowed (until 1 January 2030)
Yes, if the equipment has a leakage detection system
Yes – the ban applies only to equipment ≥40 t CO₂ eq

206

Nehéz

After 1 January 2026, may an R410A (GWP 2088) air conditioner be serviced using virgin R410A?


No – the ban covers all refrigerants with GWP ≥ 750
Only with reclaimed refrigerant
No – the ban covers all HFCs
Yes – the servicing ban for air conditioners and heat pumps covers F-gases with GWP ≥ 2500

207

Közepes

Can HFC refrigerant recovered during a repair be put straight back into the same equipment without any cleaning (filtering/drying)?


No – recovered F-gas may be used for filling only after it has been recycled or reclaimed
Yes, if the operator agrees
Yes, always
Yes, if less than 24 hours have passed

208

Közepes

Who may purchase HFCs for servicing refrigeration equipment?


Only a person holding the relevant certificate or an undertaking employing such persons
Any business
Any adult
Only the equipment operator

209

Közepes

Under what condition may non-hermetically sealed split air conditioning charged with F-gas be sold to an end user?


Unconditionally
When evidence is provided that installation will be carried out by a certified undertaking
When the user signs a statement that they will install it themselves
Only if the unit contains less than 3 kg of refrigerant

210

Közepes

By when must the holder of an F-gas certificate issued under Regulation (EU) No 517/2014 first complete refresher training or an evaluation process?


By 31 December 2030
By 12 March 2029 (and then at least every 7 years)
Never – the certificate is valid indefinitely
By 12 March 2025

211

Közepes

What must the holder of a Category I certificate (Regulation 2015/2067) do to continue using it?


Update their knowledge and skills to the level of Certificate A1 (Annex I to Regulation 2024/2215)
Nothing – Category I automatically becomes A1
Update their knowledge to the level of Certificate E
Apply for an extension without training

212

Közepes

What does Certificate C under Implementing Regulation (EU) 2024/2215 authorise?


All activities in relation to CO₂
All activities in Article 2(1) in relation to ammonia (NH₃)
Recovery of F-gases from equipment <3 kg
Leak checks without breaking into the circuit

213

Közepes

May a person enrolled in a certification training course carry out certified activities?


Yes – independently, for 6 months
Yes – under the supervision of a certified person, for no more than 24 months in total
No, never
Yes – with no time limit, if employed by a certified company

214

Közepes

How long must the operator keep the records of equipment subject to leak checks, if they are not kept in a national database?


At least 2 years
At least 1 year
Until the equipment is decommissioned
At least 5 years

215

Nehéz

Since 1 January 2025, may a new single-split air conditioner containing 1.5 kg of R410A be placed on the market?


Yes, if the unit is hermetically sealed
Yes – the ban applies only to units >12 kW
No – single splits <3 kg with F-gases of GWP ≥ 750 are banned
Yes – the ban applies from 2029

216

Nehéz

From when is it prohibited to place on the market split air-to-air systems up to 12 kW containing F-gases with GWP ≥150 (unless required for safety)?


From 1 January 2025
From 1 January 2027
From 1 January 2029
From 1 January 2035

217

Nehéz

Which persistent atmospheric degradation product of R1234yf is classed as a PFAS?


Trifluoroacetic acid (TFA)
Ozone
Carbon dioxide
Carbonic acid

218

Közepes

What is floating head pressure and what does it achieve?


It increases subcooling by flooding the condenser
It keeps a constant high condensing pressure all year
It means switching condenser fans off periodically
It lets the condensing pressure fall with ambient temperature, reducing compressor work and raising COP (requires an expansion valve that works at a small pressure difference)

219

Közepes

How do SEER/SCOP differ from EER/COP?


SEER/SCOP apply only to natural-refrigerant equipment
EER/COP are always higher than SEER/SCOP
SEER/SCOP are seasonal indicators accounting for part load and climate (EN 14825); EER/COP refer to a single operating point (EN 14511)
There is no difference – they are synonyms

220

Közepes

Which design approach can significantly reduce the F-gas charge of a large refrigeration installation?


Larger liquid-line diameters
An indirect (secondary-coolant) system or a cascade with a natural refrigerant in the low stage, plus heat exchangers with small internal volume
Adding a second liquid receiver
Omitting pipe insulation

221

Közepes

Which information must be entered in the equipment records after a leak check?


Only the equipment's energy consumption
The date and result of the check and the identity of the undertaking and person who performed it (with certificate number)
Only the date of the check
Only the operator's signature

222

Közepes

What must be done when an indirect method (e.g. parameter analysis) indicates a possible leak?


Top up the refrigerant and end the check
Carry out a direct-method examination to locate the leak
Record it and check at the next periodic inspection
Nothing – indirect methods are sufficient