F-Gas English Low GWP
All questions
HFC | Flammable | CO₂ | NH₃
Easy questions |
Medium questions |
Difficult questions
1
Difficult
What additional protective equipment will you use when soldering systems containing HC refrigerants?
| Flammable gas detector |
| Fire blanket |
| High-visibility jacket |
| Tinted safety goggles |
2
Difficult
Why can’t a sealed high-pressure switch be replaced with a standard mechanical one in a system containing a flammable refrigerant?
| The pressure switch setting will not be correct |
| There is a risk of refrigerant leakage |
| Dust and moisture may enter |
| It is a potential source of ignition |
3
Difficult
What is the minimum distance from the work area where HC refrigerants are used at which there must be no sources of ignition?
| 2 m |
| 0.5 m |
| 3 m |
| 1 m |
4
Difficult
What is the maximum safe charge for a recovery cylinder with R32 refrigerant, if it can be charged with 20 kg of R410A?
| 18 kg |
| 33 kg |
| 20 kg |
| 9 kg |
5
Difficult
According to EN 378, what is the maximum charge of an A3 refrigerant for a display unit (hermetic, with an internal condenser) located in the ground-floor retail area of a supermarket?
| 1.5 kg |
| 2.5 kg |
| 1.0 kg |
| 10 kg |
6
Difficult
How can a vacuum pump be used safely to evacuate a system containing a flammable refrigerant?
| There is no need to evacuate such systems |
| Fit a long hose to the pump outlet to remove HC away from the system |
| Use an ATEX-certified vacuum pump in a well-ventilated area |
| Position the vacuum pump 3 metres above floor level |
7
Difficult
What protective equipment must you have in your car when transporting flammable substances?
| Fire blanket |
| A fire extinguisher |
| Thick gloves |
| Tinted safety goggles |
8
Difficult
How would you remove the refrigerant from a 10kg R32 water chiller, located outdoors, before unsoldering the connections?
| Recover the R32 until a vacuum is achieved, then charge the system with nitrogen to a relative pressure of 0.1 bar g |
| Recover the R32 until a vacuum is achieved |
| Vent the R32 to the outside; charge the system with nitrogen until an overpressure is achieved, vent and drain the system twice, charge the system with nitrogen a third time and vent |
| Vent the R32 to the outside and drain the system |
9
Difficult
Which of the following leak detection methods cannot be used to locate an HC refrigerant leak?
| Soapy water solution |
| Leak detection foam |
| Electronic leak detector for flammable refrigerants |
| Electronic HFC leak detector |
10
Difficult
What is the most important difference between a flammable refrigerant recovery unit and a standard one?
| Different connection sizes |
| Different low-pressure switch setting |
| A flammable refrigerant recovery unit has no ignition sources |
| A different colour for the station |
11
Difficult
Which of the following is a source of ignition?
| ‘n’ type thermostat |
| Ex-certified evaporator fan motor |
| Defrost heating element |
| Contactor |
12
Difficult
What substance is produced when R32 is burnt?
| Carbon monoxide |
| Hydrogen fluoride |
| Phosgene |
| Hydrochloric acid |
13
Difficult
What type of refrigerant is R1234ze?
| Hydrofluoroolefin |
| Hydrochlorofluoro-hydrocarbon |
| Chloro-fluoro-hydrocarbon |
| Hydrocarbon |
14
Difficult
What hazards does a Group A3 refrigerant pose?
| Low toxicity, moderate flammability |
| Low toxicity, highly flammable |
| High toxicity, moderate flammability |
| High toxicity, high flammability |
15
Difficult
According to EN 378, what is the maximum charge of R290 in a cold store measuring 5 m x 3 m x 2.5 m in height (the LFL for R290 is 0.038 kg/m³)?
| 1.0 kg |
| 1.5 kg |
| 0.285 kg |
| 4.93 kg |
16
Difficult
What is the cooling capacity of R32 compared to R410A?
| 130% |
| 75% |
| 60% |
| 105% |
17
Difficult
Why are Ex-certified evaporator fan motors used in some systems with flammable refrigerants?
| Because they are more energy-efficient |
| Because they are more reliable |
| To avoid a source of ignition in the event of a flammable refrigerant leak |
| Because they must be kept running continuously to disperse the leaking refrigerant |
18
Difficult
Why is the difference in density between HC and HFC refrigerants important?
| Because it increases operating pressures |
| Because it affects the charge weight |
| Because it affects energy efficiency |
| Because it affects the charging rate |
19
Difficult
What is the GWP value for R290?
| 675 |
| 7 |
| A. 0.02 |
| 3 |
20
Difficult
Which of the following is not a source of ignition?
| An Ex-certified fan motor |
| Open mechanical pressure switch |
| Electrical switch |
| Light switch |
21
Difficult
What is R290?
| Propene |
| Propene |
| Propylene |
| Butane |
22
Difficult
According to EN 378, what is the maximum HC refrigerant charge for a display unit (hermetic system with an internal condenser) located in the ground-floor shopping area of a supermarket?
| 1.0 kg |
| 1.5 kg |
| 2.5 kg |
| 150 g |
23
Difficult
Why can’t a standard relay be fitted when retrofitting a compressor’s electrical system for flammable refrigerants?
| The method of starting the compressor motor differs from that used with HFCs |
| It could be a source of ignition |
| Current consumption differs for compressors using flammable refrigerants compared to those using HFCs |
| A relay is never required for compressors using flammable refrigerants |
24
Difficult
What is the minimum distance from the work area where HC refrigerants are used at which there must be no sources of ignition?
| 3 m |
| 10 m |
| 1 m |
| 5 m |
25
Difficult
What is the safe charge for a recovery cylinder with R290 refrigerant, if it can be charged with 10 kg of R404A?
| 20 kg |
| 3.6 kg |
| 8 kg |
| 17 kg |
26
Difficult
How can a vacuum pump be used safely to evacuate a system containing R290?
| Position the vacuum pump 3 metres above floor level |
| There is no need to evacuate systems containing R290 |
| Use an ATEX-certified vacuum pump in a well-ventilated area |
| Fit a long hose to the pump outlet to remove HC away from the system |
27
Difficult
In accordance with ADR regulations, what protective equipment must you have in your vehicle when transporting flammable refrigerants?
| Thick gloves |
| A fire extinguisher |
| Fire blanket |
| Tinted safety goggles |
28
Difficult
How do you ensure it is safe to light the torch needed to desolder joints in a system that has been evacuated of flammable refrigerant?
| Purge the system with oxygen-free nitrogen |
| Ensure the area is well ventilated and use a flammable gas detector to check the area |
| You must not desolder joints on a system containing a flammable refrigerant; they must be cut using a pipe cutter |
| Work outdoors |
29
Difficult
How would you remove the refrigerant from a system containing 100 g of R1270 so that it is ready for the joints to be desoldered?
| Recover the R1270 until a vacuum is achieved, then charge the system with nitrogen to a relative pressure of 0.1 bar g |
| Vent the R1270 to the outside and drain the system |
| Vent the R1270 to the outside; charge the system with nitrogen until an overpressure is reached, vent and evacuate the system twice, charge the system with nitrogen a third time and vent |
| Recover the R1270 until a vacuum is achieved |
30
Difficult
Which of the following leak detection methods cannot be used to locate a leak of R290 refrigerant?
| Electronic HFC leak detector |
| Leak detection foam |
| Electronic leak detector for flammable refrigerants |
| Fluorescent dye and a UV lamp |
31
Difficult
Why can’t recovery stations designed for HFCs be used with R600a?
| It contains ignition sources |
| The low-pressure switch setting will not be suitable for R600a due to its lower operating pressure |
| The oil in the recovery unit is not soluble in R600a |
| The recovery unit cannot withstand the working pressure of R600a |
32
Difficult
According to EN 378, what is the maximum charge of R1234ze in a cold store measuring 5 m x 3 m x 2.5 m in height (the LFL for R1234ze is 0.303 kg/m³)?
| 227 kg |
| 6.18 kg |
| 618 kg |
| 2.27 kg |
33
Difficult
What type of refrigerant is R32?
| Hydrofluoroolefin |
| Hydrofluorocarbon |
| Carbon dioxide |
| Hydrocarbon |
34
Difficult
What hazards do A2L refrigerants pose?
| High toxicity, high flammability |
| Low toxicity, moderate flammability |
| High toxicity, moderate flammability |
| Low toxicity, high flammability |
35
Difficult
What danger is associated with the combustion of HFO or HFC refrigerants?
| Phosgene is produced |
| Citric acid is produced |
| Hydrogen fluoride is produced |
| Nitrous oxide is produced |
36
Difficult
What is the approximate displacement volume required for a compressor running on R600a compared to one running on R134a to achieve the same cooling capacity?
| Seven times |
| Twice |
| The same |
| Half |
37
Difficult
What is the GWP value for R32?
| 0 |
| 3 |
| 7 |
| 675 |
38
Difficult
Why is the accuracy of the charge weight more important for systems critically charged with R290 compared to those using HFCs
| Because R290 is only used in systems with a charge of less than 150g |
| Due to lower operating pressures |
| The charge mass is significantly lower than in an HFC system, as the density is much lower |
| Because these systems never have liquid receivers |
39
Difficult
Why does the condenser fan run continuously in some systems using R1270?
| To dilute the refrigerant in the event of a leak |
| To reduce energy consumption |
| To prevent the build-up of contaminants in the condenser |
| To ensure that the discharge pressure never becomes excessive |
40
Difficult
What must be included on the label of a cylinder containing a flammable refrigerant?
| Net weight only |
| Information about the cylinder owner |
| The name of the refrigerant, the hazard symbol and basic safety information |
| Agent name only |
41
Difficult
Why does the absence of a ‘flammable agent’ label on the system pose a significant hazard?
| It has no significant impact on safety |
| It may lead to the incorrect selection of oil |
| It may lead to the use of tools that are a source of ignition |
| It reduces the system’s efficiency |
42
Difficult
Which set of information on the label of a flammable agent cylinder is crucial from a safety perspective?
| Gross weight and batch number |
| Manufacturer’s name and country of origin |
| Name of the substance, hazard pictogram, UN number |
| Cylinder colour and date of manufacture |
43
Difficult
What is the requirement regarding the labelling of an installation containing a flammable substance?
| Labelling is not required for hermetically sealed systems |
| Colour-coding of pipes is sufficient |
| Labelling is required only in technical rooms |
| The labelling must indicate the type of substance and the flammability hazard |
44
Difficult
What are the potential consequences of using unsuitable connections in a system containing a flammable substance?
| No impact on safety |
| Merely installation difficulties |
| Risk of leakage and the formation of an explosive mixture |
| Merely a reduction in efficiency |
45
Difficult
What is the purpose of installing gas detectors in a room with a refrigeration system?
| Monitoring pipe pressure |
| Regulating compressor capacity |
| Measuring the refrigerant temperature |
| Early detection of refrigerant leaks and prevention of health risks |
46
Difficult
How often should gas detection sensors in the service room be checked?
| Once every 5 years |
| In accordance with the manufacturer’s instructions and applicable health and safety regulations |
| Only after a leak has occurred |
| Before each start-up of the unit |
47
Difficult
Where should a gas detector be positioned in accordance with EN 378?
| Anywhere in the room |
| Near the control panel |
| On the ceiling if the gas is lighter or heavier than air; near the floor if it is lighter or heavier |
| Only at the entrance to the room |
48
Difficult
How should an employee respond when a gas alarm is triggered?
| Switch off the system and wait for the alarm to stop |
| Leave the room immediately and notify their supervisor |
| Carry on working until they see a leak |
| Reduce the pressure in the system |
49
Difficult
What safety checks should be carried out when installing a new refrigeration system?
| Only the compressor power |
| The presence of health and safety signage, adequate ventilation and gas detectors |
| The colour of pipes and hoses |
| Is the air filter new? |
50
Difficult
Gas detectors should be installed in rooms where:
| The amount of refrigerant exceeds a specified permissible threshold |
| The room is less than 5 m² |
| Ventilation is natural |
| Any refrigerant is present, regardless of the quantity |
51
Difficult
What is the minimum number of emergency exits in a plant room (refrigeration plant room) and how should they be signposted?
| One exit with an information sign about the refrigerant |
| At least two exits, but signage is optional |
| Exits do not need to be signposted if the room is small |
| One exit, clearly marked in the direction of escape |
52
Difficult
Which measure, when installing a system using a flammable refrigerant, improves its energy efficiency?
| Restriction of ventilation |
| No leak test |
| Thorough leak testing and vacuuming |
| Increasing the refrigerant charge |
53
Difficult
How do leaks affect systems using flammable refrigerants?
| They cause refrigerant loss, reduced efficiency and a fire hazard |
| They lower the temperature |
| Have no effect |
| They improve efficiency |
54
Difficult
Why is it important to limit the amount of refrigerant in HC systems?
| It lowers the temperature |
| It has no effect |
| It reduces the risk of explosion and improves the system’s operational safety |
| It increases efficiency |
55
Difficult
Why is the cleanliness of heat exchangers in HC systems important?
| It improves heat transfer and reduces energy consumption |
| It doesn’t matter |
| It increases the pressure |
| Causes leaks |
56
Difficult
What maintenance measures improve the efficiency of a system using a flammable refrigerant?
| Disabling safety devices |
| Increasing the refrigerant charge |
| Regular checks for leaks and operating parameters |
| Lack of servicing |
57
Difficult
How does the correct selection of components affect a system using a flammable refrigerant?
| It lowers the temperature |
| It doesn’t matter |
| It ensures safe and optimal operation and minimises energy losses |
| It increases the amount of refrigerant |
58
Difficult
Why is it important to use the correct service tools in HC systems?
| It doesn’t matter |
| It increases energy consumption |
| Causes leaks |
| It ensures operational safety and reduces refrigerant losses |
59
Difficult
How does pipe insulation affect the efficiency of systems containing HC?
| It doesn’t matter |
| Causes leaks |
| It reduces energy losses and improves efficiency |
| It increases the pressure |
60
Difficult
What hazards are associated with a Class A3 safety agent?
| High flammability, lower toxicity |
| High toxicity, does not propagate flames |
| Lower toxicity, does not propagate flames |
| Slightly flammable, lower toxicity |
61
Difficult
18 What is the GWP of R32 (according to AR4)?
| 3945 |
| 0 |
| 6 |
| 675 |
62
Difficult
What factors are taken into account when determining the maximum charge for comfort air-conditioning/heating applications?
| Practical limit, room volume |
| Lower flammability limit, height of the indoor unit, floor area |
| Practical limit, height of the indoor unit, floor area |
| Lower flammability limit, room volume |
63
Difficult
What compressor displacement is required for R1270, relative to R404A compressors for the medium-temperature range (cold store)?
| Similar |
| 50% |
| 150% |
| 600% |