F-Gas English Low GWP
All questions
HFC | Flammable | CO₂ | NH₃
Easy questions |
Medium questions |
Difficult questions
1
Difficult
What is the role of a suction liquid separator (also in systems with flammable or toxic refrigerants)?
| It prevents liquid refrigerant from entering the compressor |
| It separates liquid from oil |
| It heats the refrigerant before the evaporator |
| It is used only to measure moisture |
2
Difficult
What is the function of an oil separator in systems using flammable or toxic refrigerants?
| Heats the refrigerant before it enters the evaporator |
| Separates oil from the refrigerant and facilitates the return of oil to the compressor |
| It prevents liquid from entering the compressor |
| They are used solely to measure the moisture content of the refrigerant |
3
Difficult
Why are PFAS formed by the decomposition of certain F-gases (e.g. TFA from HFOs) problematic?
| They are readily biodegradable |
| They cause rapid cooling of the atmosphere |
| They are climate- and environment-neutral |
| They are very persistent, accumulate in the environment (e.g. water) and may be toxic |
4
Difficult
Which statement about installing Schrader valves is correct?
| Hydrocarbons leak through Schrader valves |
| When brazing the valve body, the core must be removed, then refitted and tightened to the correct torque |
| Schrader valves must not be used in R744 systems |
| All Schrader cores are suitable for all refrigerants |
5
Difficult
How does an undercharge affect the high-pressure side (without discharge pressure control)?
| Discharge pressure lower, subcooling higher |
| Discharge pressure higher, subcooling lower |
| Discharge (condensing) pressure and subcooling will both be lower |
| Discharge pressure higher, subcooling higher |
6
Difficult
What is the benefit of adding helium as a tracer gas to nitrogen in a pressure test?
| It has a distinctive odour that helps locate the leak |
| 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 |
7
Difficult
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 set pressure increases |
| The valve stays fully open permanently |
| The valve no longer opens |
8
Difficult
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 = T₁/(p₁ × T₂) |
| p₂ = T₂/(p₁ × T₁) |
| p₂ = (p₁ × T₂)/T₁ |
| p₂ = (p₁ × T₁)/T₂ |
9
Difficult
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 |
10
Difficult
Leak checks can be carried out using various methods. Which pair is correct?
| Direct and indirect methods |
| Physical and chemical methods |
| Material quality control methods and electronic methods |
| Methods with and without quality control of supplies |
11
Difficult
To whom can leak checks of stationary refrigeration equipment containing F-gases be entrusted?
| A natural person holding a certificate covering leak checks (A1, A2 within its charge limit, or E) |
| Any leak-testing specialist |
| A person who has carried out such checks before |
| An employee appointed by the owner of the installation |
12
Difficult
What conditions must be met to use UV dye for leak checking?
| Manufacturer approval of the method and a certificate covering breaking into the circuit |
| It is sufficient to have a UV lamp, dye and safety goggles |
| It is sufficient that introducing dye into the circuit is technically feasible |
| A UDT authorisation for pressure testing is required |
13
Difficult
Which leak-checking methods are considered direct methods?
| 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 |
| Vacuum test and foam solution |
14
Difficult
What do indirect leak-checking methods involve?
| Leak detection with UV dye |
| Ultrasonic measurement |
| A visual and manual check and analysis of parameters: pressure, temperature, compressor current, liquid levels and recharge volume |
| Leak detection with an electronic detector |
15
Difficult
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 |
| The pump runs continuously to hold the required vacuum for the test |
| With the pump running, you watch the vacuum gauge reading |
16
Difficult
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. |
| On initial commissioning. |
| At least once every 12 months. |
| Once every six months. |
17
Difficult
How often should leak tests be carried out on equipment containing 7 kg of R404A refrigerant (27.45 tonnes of CO₂ equivalent)?
| Once every six months. |
| On initial commissioning. |
| At least once every 12 months. |
| Only when servicing the unit. |
18
Difficult
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 equipment operates in an enclosed space |
| the charge is 100 kg or more of ozone-depleting substances |
19
Difficult
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 |
| Checking with a foaming solution |
| Measurement with a handheld electronic detector |
20
Difficult
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. |
| At any time. |
| At the next periodic inspection. |
| Between 24 hours and 1 month after the repair. |
21
Difficult
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 12 months |
| Every 6 months |
| Every month |
22
Difficult
What is the basis of the GWP values in Regulation (EU) 2024/573?
| 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) |
| AR6 for all substances |
| AR4 for all substances |
| Each Member State sets its own GWP values |
23
Difficult
An air conditioner (not hermetically sealed) contains 2.5 kg of R410A (GWP 2088). How often must it be checked for leaks?
| At least every 12 months (5.22 t CO₂ eq) |
| No checks required (below 3 kg) |
| Every 6 months |
| Every 3 months |
24
Difficult
When is labelled hermetically sealed equipment containing HFCs (Annex I) exempt from leak checks?
| Always, regardless of charge |
| When it contains less than 5 t CO₂ eq |
| 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 |
25
Difficult
Is a chiller containing 50 kg of R1234ze(E) subject to leak checks under Regulation (EU) 2024/573?
| No – the threshold is 5 t CO₂ eq and 50 kg of R1234ze is below 1 t CO₂ eq |
| No – HFOs are not subject to leak checks |
| Yes – every 12 months, because its GWP is low |
| Yes – at least every 6 months (every 12 months with a leakage detection system) |
26
Difficult
In 2026, may an existing refrigeration installation using R404A (GWP 3922) be topped up with virgin refrigerant?
| Yes, if the equipment has a leakage detection system |
| No – only reclaimed or recycled R404A is allowed (until 1 January 2030) |
| Yes – the ban applies only to equipment ≥40 t CO₂ eq |
| Yes – bans apply only to new equipment |
27
Difficult
After 1 January 2026, may an R410A (GWP 2088) air conditioner be serviced using virgin R410A?
| Only with reclaimed refrigerant |
| No – the ban covers all refrigerants with GWP ≥ 750 |
| Yes – the servicing ban for air conditioners and heat pumps covers F-gases with GWP ≥ 2500 |
| No – the ban covers all HFCs |
28
Difficult
Since 1 January 2025, may a new single-split air conditioner containing 1.5 kg of R410A be placed on the market?
| No – single splits <3 kg with F-gases of GWP ≥ 750 are banned |
| Yes, if the unit is hermetically sealed |
| Yes – the ban applies only to units >12 kW |
| Yes – the ban applies from 2029 |
29
Difficult
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 2027 |
| From 1 January 2025 |
| From 1 January 2035 |
| From 1 January 2029 |
30
Difficult
Which persistent atmospheric degradation product of R1234yf is classed as a PFAS?
| Carbon dioxide |
| Ozone |
| Carbonic acid |
| Trifluoroacetic acid (TFA) |