F Gas Exam questions and answers 2024\2025
A+ Grade
The condition of the refrigerant entering the expansion device is?
- correct answer High pressure sub cooled liquid
The indications of a refrigerant leak on a refrigeration system is most likely if the following has been
observed?
- correct answer The evaporator superheat is high with bubbles in the liquid line sight glass
The EC F Gas Regulations 517/2014 requires refrigeration systems containing > 50 and < 500 of an HFC
refrigerant without an automatic leak detector to be leak tested?
- correct answer 6 monthly
Which of the following TEV superheat settings is likely to cause refrigeration system hermetic
compressor to run continuously and overheat?
- correct answer 20K
Under the F Gas Regulations when should a newly installed system be checked for refrigeration leakage?
- correct answer Immediately after being put into service
The residual flux that is left on the outside of a brazed joint must be removed because?
- correct answer The flux absorbs water from the air and corrodes the pipework
What pipe diameter is least likely to fail when carrying out the strength test using OFN?
- correct answer 1 inch
Which one of the following effects would result in an increase in system efficiency?
- correct answer A reduction in vapour specific volume
, The ODP of the refrigerant R22 is?
- correct answer 0.05
What would cause a reduction in the efficiency of a cooling plant?
- correct answer High pressure ratio
Which one of the following would improve the energy efficiency of an air conditioning or refrigeration
system the most?
- correct answer Lowering the condensing temperature and raising the evaporating temperature
Why might a unit short cycle on low pressure control?
- correct answer Refrigerant loss
What refrigerant is covered by the requirements of EC Regulations 517/2014?
- correct answer R404A
What identifies that a system may have lost refrigerant?
- correct answer Bubbles in the sight glass
The term indirect leak checking refers to?
- correct answer The calculation of the correct operating conditions by taking pressure and temperature
readings
To find a suspected refrigerant leak on a freezer room evaporator it's best to?
- correct answer Leak test the evaporator with the unit in shut down
If the fins on the evaporator become blocked what is the result on the suction vapour?
- correct answer Pressure and temperature fall
To calculate the system compression ratio?
- correct answer Divide discharge pressure by suction pressure (gauge)
A+ Grade
The condition of the refrigerant entering the expansion device is?
- correct answer High pressure sub cooled liquid
The indications of a refrigerant leak on a refrigeration system is most likely if the following has been
observed?
- correct answer The evaporator superheat is high with bubbles in the liquid line sight glass
The EC F Gas Regulations 517/2014 requires refrigeration systems containing > 50 and < 500 of an HFC
refrigerant without an automatic leak detector to be leak tested?
- correct answer 6 monthly
Which of the following TEV superheat settings is likely to cause refrigeration system hermetic
compressor to run continuously and overheat?
- correct answer 20K
Under the F Gas Regulations when should a newly installed system be checked for refrigeration leakage?
- correct answer Immediately after being put into service
The residual flux that is left on the outside of a brazed joint must be removed because?
- correct answer The flux absorbs water from the air and corrodes the pipework
What pipe diameter is least likely to fail when carrying out the strength test using OFN?
- correct answer 1 inch
Which one of the following effects would result in an increase in system efficiency?
- correct answer A reduction in vapour specific volume
, The ODP of the refrigerant R22 is?
- correct answer 0.05
What would cause a reduction in the efficiency of a cooling plant?
- correct answer High pressure ratio
Which one of the following would improve the energy efficiency of an air conditioning or refrigeration
system the most?
- correct answer Lowering the condensing temperature and raising the evaporating temperature
Why might a unit short cycle on low pressure control?
- correct answer Refrigerant loss
What refrigerant is covered by the requirements of EC Regulations 517/2014?
- correct answer R404A
What identifies that a system may have lost refrigerant?
- correct answer Bubbles in the sight glass
The term indirect leak checking refers to?
- correct answer The calculation of the correct operating conditions by taking pressure and temperature
readings
To find a suspected refrigerant leak on a freezer room evaporator it's best to?
- correct answer Leak test the evaporator with the unit in shut down
If the fins on the evaporator become blocked what is the result on the suction vapour?
- correct answer Pressure and temperature fall
To calculate the system compression ratio?
- correct answer Divide discharge pressure by suction pressure (gauge)
