Concerned about the level of knowledge required to pass the theory part of the F-gas regulations? Try our test based on real F-gas assessment questions kindly supplied to us by City & Guilds and based on its 2079 Level 2 exam.
MANY engineers are concerned about the degree of knowledge required to pass the theory part of the F-gas regulations.
While most seem confident that they can pass the practical part of the exam, the 40-question online theory test has left many wondering whether they have sufficient knowledge to pass or whether they would benefit from a refresher course as offered by many of the training organisations.
To give you a taster of what to expect, we reproduce here a sample of the type of multiple choice theory questions that candidates might encounter in the City & Guilds 2079 Level 2 Award in the F-gas regulations. They are taken from the City & Guilds website www.cityandguilds.com.
All four 2079 online GOLA tests are drawn from the same pool of questions but each category has a different test specification. The questions here are all drawn from Category I but some will also also appear in tests for Categories II, III or IV.
While these are real questions from the C&G test, prospective 2079 candidates should seek the opinion of the training providers as to whether they would benefit from a refresher course before undertaking the F-gas assessment.
The relevant C&G units are:
2079-101: Category I – leak checking, recovery, installation, service and maintenance of equipment.
2079-201: Category II – installation, service and maintenance of equipment with a charge of less than 3 kg (6 kg if hermetically sealed) and leakage checking.
2079-301: Category III – recovery of refrigerant.
2079-401: Category IV – leakage checking.
1. Which one of the following terms describes enthalpy?
a) Heat content per unit volume
b) Heat content per unit temperature
c) Heat content per unit mass
d) Heat content per unit time
2. On the diagram shown above, process line 5 to 6 represents:
a) suction line superheat
b) refrigeration effect
c) compressor ‘work done’
d) liquid line sub cooling
3. The function of an evaporative condenser is to:
a) absorb sensible heat to change vapour to liquid
b) reject sensible heat to change vapour to liquid
c) absorb latent heat to change vapour to liquid
d) reject latent heat to change vapour to liquid
4. Subcooling is established when:
a) refrigerant liquid is cooled below its boiling point
b) condenser fan speed is increased
c) liquid injection is fitted to a system
d) the condensing temperature is reduced
5.The most efficient operating temperatures for a chill coldroom designed to maintain a space temperature of +2°C with ‘air on’ to the condenser at 32°C are:
a) evaporating at -8ºC and condensing at + 48ºC
b) evaporating at -8ºC and condensing at + 50ºC
c) evaporating at -8ºC and condensing at + 52ºC
d) evaporating at -8ºC and condensing at + 54ºC
6. Which one of the following refrigerants is most likely to suffer from changes in its composition after leakage from a static system?
a)R22 b)R134a c)R245fa d)R407C
7. Which of the following refrigerant conditions will provide a clear liquid line sight glass?
a) Saturated liquid and saturated vapour
b) Saturated two-phase mixture
c) Subcooled liquid
d) Superheated liquid
8. Which one of the following environmental issues is addressed by the Kyoto Protocol?
a) Ozone depletion
b) Volatile organic compounds
c) Climate change
d) Heavy oil particulates
9. Which one of the following refrigerants has least impact on direct global warming?
a)R134a b) R404A c)R717 d)R744
10(a). The Energy Efficiency Ratio of a heat pump system is found from:
a) Heating capacity x compressor motor input power
b) Heating capacity x total system input power
c) Heating capacity
Compressor motor input power
d) Heating capacity
Total system input power
10(b) As the difference between condensing temperature and evaporating temperature decreases:
a) Work done decreases and discharge temperature decreases
b) Work done decreases and discharge temperature increases
c) Work done increases and discharge temperature decreases
d) Work done increases and discharge temperature increases
11. Which F-gas Category qualification is required to recover refrigerant from an air conditioning system which has a charge of 7.5kg of R407C?
a)I b)II c)III d)IV
12. Which of the following saturation temperatures satisfies the BS EN 378 requirement for pressure testing the high side of cooling systems fitted with air cooled condensers?
a)32ºC b)43ºC c)55ºC d)63ºC
13. Which of the following is most likely to increase refrigerant leakage potential from an air to water heat pump system? Excessive:
a) expansion valve superheat
b) liquid line subcooling
c) discharge vapour superheat
d) expansion line subcooling
14. Which one of the following is the correct method for transporting recovered waste compressor oil back to licensed waste manager?
a) Record oil type and weight and secure it in vehicle
b) Record oil quantity and wedge it in vehicle with tool box
c) Record oil quantity, sign it over to your company and secure it in vehicle
d) Record oil colour, sign it over to your company and wedge it in vehicle
15. The function of the compressor is to:
a) circulate refrigerant vapour and increase pressure
b) control refrigerant flow and decrease pressure
c) reject latent heat to cause a change of state
d) absorb latent heat to cause a change of state
16. Which one of the following conditions is most likely to indicate imminent compressor motor failure on a blast freezer system? The compressor body is:
a) frosted
b) cool to touch
c) warm
d) too hot to touch
17. Which one of the following condenser types would run with the lowest condensing temperature?
a) Natural convection air cooled
b) Forced convection air cooled
c) Water cooled
d) Evaporative
18. A clean condenser on an air conditioning system leads to:
a) higher discharge pressure and higher efficiency
b) lower discharge pressure and lower efficiency
c) higher discharge pressure and lower efficiency
d) lower discharge pressure and higher efficiency
19. For every 1ºC that the evaporating temperature is increased, cooling capacity:
a) increases by 3% and energy use increases by 3%
b) increases by 3% and energy use decreases by 3%
c) decreases by 3% and energy use increases by 3%
d) decreases by 3% and energy use decreases by 3%
20. Which one of the following is most likely to cause the evaporator of an unprotected water chiller to freeze solid?
a) Refrigerant undercharge
b) Refrigerant overcharge
c) Higher than normal waterside temperature
d) Lower than normal waterside temperature
21. The function of an expansion valve is to:
a) circulate refrigerant vapour and increase pressure
b) control refrigerant flow and decrease pressure
c) reject latent heat to cause a change of state
d) absorb latent heat to cause a change of state
22. Which one of the following thermostatic expansion valve superheat settings is likely to cause a system hermetic compressor to run continuously and overheat?
a)5K b)10K c)15K d)20K
23. Which one of the following refrigerants is classified as an Ozone Depleting Substance?
a)R22 b)R134a c)R600a d)R744
24. Which one of the following international agreements is responsible for the phase out of HCFCs?
a) Kyoto Protocol
b) Lisbon Protocol
c) Montreal Protocol
d) Geneva Protocol
25. Which one of the following refrigerant hazards can make an affected person feel ‘high’?
a) Asphyxiation
b) Thermal decomposition
c) Central nervous system effect
d) Cardiac sensitization
26. Residual flux on the outside of a brazed copper pipe must be removed because:
a) it absorbs water from the air and corrodes the pipe
b) it gives off harmful gases
c) it causes the insulation to be conductive to heat
d) excessive flux appears profligate and wasteful
27. Which one of the following pipe diameters is most likely to fail when strength tested with oxygen-free nitrogen?
a) 1⁄2 inch
b) 11⁄8 inch
c) 21⁄4 inch
d) 41⁄8 inch
Answers
1 c, 2 b, 3 d, 4 a, 5 a, 6 d, 7 c, 8 c, 9 c,
10(a) d, 10(b) a, 11 a, 12 c, 13 c, 14 c,
15 a, 16 d, 17 d, 18 d, 19 b, 20 d,
21 b, 22 d, 23 a, 24 c, 25 c, 26 a, 27 d.