BC MUNICIPAL HVAC TECHNICIAN: 313A REFRIGERATION & AIR
CONDITIONING MECHANIC EXAM 2026/2027 | 100% VERIFIED
QUESTIONS AND CORRECT ANSWERS | LATEST
1. What is the primary refrigerant used in most modern residential
HVAC systems in BC?
ANSWER : R-410A (also known as Puron) is the primary refrigerant
used in most modern residential HVAC systems in BC, replacing the
older R-22 (Freon) which has been phased out under the Montreal
Protocol.
2. What is the boiling point of R-410A at atmospheric pressure?
ANSWER : R-410A has a boiling point of approximately -51.4°C (-
60.5°F) at atmospheric pressure (101.3 kPa).
3. Define the term 'superheat' in refrigeration.
ANSWER : Superheat is the temperature of a vapour above its
saturation temperature at a given pressure. It measures how much heat
has been added to refrigerant vapour beyond the point at which it
became fully vaporized.
4. What is subcooling in a refrigeration system?
ANSWER : Subcooling is the process of cooling a liquid refrigerant
below its condensing temperature at a given pressure. It ensures the
refrigerant entering the expansion device is fully liquid, improving system
efficiency.
BC Municipal HVAC Technician Exam Guide | Page 1 of 39
,5. What are the four basic components of a vapour-compression
refrigeration cycle?
ANSWER : The four basic components are: (1) Compressor, (2)
Condenser, (3) Metering/expansion device (TXV or fixed orifice), and (4)
Evaporator.
6. What happens to refrigerant in the evaporator?
ANSWER : In the evaporator, low-pressure liquid refrigerant absorbs
heat from the surrounding air or medium, causing it to boil and vaporize.
This heat absorption creates the cooling effect.
7. What is the purpose of the condenser in a refrigeration system?
ANSWER : The condenser rejects heat absorbed from the evaporator
and the heat of compression. Hot, high-pressure refrigerant vapour
releases heat to the outdoor air (or water), condensing back into a liquid.
8. What is a Thermostatic Expansion Valve (TXV) and what does it
control?
ANSWER : A TXV (Thermostatic Expansion Valve) is a metering device
that controls the flow of refrigerant into the evaporator. It maintains a
constant superheat at the evaporator outlet by sensing bulb pressure
and spring pressure.
9. What is the Global Warming Potential (GWP) of R-410A?
ANSWER : R-410A has a GWP of 2,088. Due to its high GWP, it is
being phased down in Canada under the HFC regulations, with R-32 and
R-454B proposed as lower-GWP alternatives.
10. What does ASHRAE stand for?
ANSWER : ASHRAE stands for American Society of Heating,
Refrigerating and Air-Conditioning Engineers. It is the primary technical
standards body for HVAC systems referenced across Canada.
BC Municipal HVAC Technician Exam Guide | Page 2 of 39
,11. What is the difference between R-22 and R-410A?
ANSWER : R-22 is an HCFC refrigerant that is ozone-depleting and
was phased out in Canada by 2020. R-410A is an HFC refrigerant with
no ozone depletion potential (ODP=0), higher operating pressures, and
better energy efficiency, though it has a higher GWP.
12. What is the critical temperature of a refrigerant?
ANSWER : The critical temperature is the temperature above which a
substance cannot exist as a liquid, regardless of the pressure applied.
Above the critical temperature, the refrigerant remains a gas.
13. What is latent heat?
ANSWER : Latent heat is the heat absorbed or released during a phase
change (e.g., liquid to vapour) without a change in temperature. In
refrigeration, latent heat of vaporization is the heat absorbed when
refrigerant evaporates.
14. What is sensible heat?
ANSWER : Sensible heat is heat that causes a change in temperature
of a substance without changing its phase. It is measurable with a
thermometer, unlike latent heat.
15. What is the Coefficient of Performance (COP) of a refrigeration
system?
ANSWER : COP is the ratio of useful cooling (heat removed) to the
work input (energy consumed by the compressor). COP = Q_evap /
W_compressor. A higher COP indicates greater efficiency.
16. What refrigerant is commonly used in commercial refrigeration
(walk-in coolers) in BC?
ANSWER : R-404A and R-134a are common in commercial
refrigeration. However, due to high GWP regulations, R-448A and R-
449A are increasingly used as lower-GWP retrofits.
BC Municipal HVAC Technician Exam Guide | Page 3 of 39
, 17. What is the purpose of a filter-drier in a refrigeration system?
ANSWER : A filter-drier removes moisture and contaminants from the
refrigerant circuit. Moisture can cause acid formation and freeze at the
expansion device, so the drier contains desiccant materials (silica gel or
molecular sieve) to absorb it.
18. What is a sight glass used for in HVAC/R systems?
ANSWER : A sight glass allows a technician to visually inspect the
refrigerant flow. Bubbles in the sight glass indicate insufficient refrigerant
charge or a restriction upstream. A moisture indicator changes colour if
moisture is present.
19. What is refrigerant migration?
ANSWER : Refrigerant migration occurs when refrigerant migrates from
the high-pressure side to the compressor crankcase during the off-cycle,
mixing with the oil. On startup, floodback can damage the compressor
due to liquid slugging.
20. What is 'liquid slugging' and why is it harmful?
ANSWER : Liquid slugging occurs when liquid refrigerant or oil enters
the compressor cylinder. Since liquids are incompressible, this can crack
valve plates, pistons, or the compressor body, causing catastrophic
failure.
21. What does the term 'saturation temperature' mean?
ANSWER : Saturation temperature is the temperature at which a
refrigerant changes state (liquid to vapour or vice versa) at a specific
pressure. It is read from a pressure-temperature (P-T) chart for a given
refrigerant.
22. What is an azeotrope refrigerant blend?
BC Municipal HVAC Technician Exam Guide | Page 4 of 39
CONDITIONING MECHANIC EXAM 2026/2027 | 100% VERIFIED
QUESTIONS AND CORRECT ANSWERS | LATEST
1. What is the primary refrigerant used in most modern residential
HVAC systems in BC?
ANSWER : R-410A (also known as Puron) is the primary refrigerant
used in most modern residential HVAC systems in BC, replacing the
older R-22 (Freon) which has been phased out under the Montreal
Protocol.
2. What is the boiling point of R-410A at atmospheric pressure?
ANSWER : R-410A has a boiling point of approximately -51.4°C (-
60.5°F) at atmospheric pressure (101.3 kPa).
3. Define the term 'superheat' in refrigeration.
ANSWER : Superheat is the temperature of a vapour above its
saturation temperature at a given pressure. It measures how much heat
has been added to refrigerant vapour beyond the point at which it
became fully vaporized.
4. What is subcooling in a refrigeration system?
ANSWER : Subcooling is the process of cooling a liquid refrigerant
below its condensing temperature at a given pressure. It ensures the
refrigerant entering the expansion device is fully liquid, improving system
efficiency.
BC Municipal HVAC Technician Exam Guide | Page 1 of 39
,5. What are the four basic components of a vapour-compression
refrigeration cycle?
ANSWER : The four basic components are: (1) Compressor, (2)
Condenser, (3) Metering/expansion device (TXV or fixed orifice), and (4)
Evaporator.
6. What happens to refrigerant in the evaporator?
ANSWER : In the evaporator, low-pressure liquid refrigerant absorbs
heat from the surrounding air or medium, causing it to boil and vaporize.
This heat absorption creates the cooling effect.
7. What is the purpose of the condenser in a refrigeration system?
ANSWER : The condenser rejects heat absorbed from the evaporator
and the heat of compression. Hot, high-pressure refrigerant vapour
releases heat to the outdoor air (or water), condensing back into a liquid.
8. What is a Thermostatic Expansion Valve (TXV) and what does it
control?
ANSWER : A TXV (Thermostatic Expansion Valve) is a metering device
that controls the flow of refrigerant into the evaporator. It maintains a
constant superheat at the evaporator outlet by sensing bulb pressure
and spring pressure.
9. What is the Global Warming Potential (GWP) of R-410A?
ANSWER : R-410A has a GWP of 2,088. Due to its high GWP, it is
being phased down in Canada under the HFC regulations, with R-32 and
R-454B proposed as lower-GWP alternatives.
10. What does ASHRAE stand for?
ANSWER : ASHRAE stands for American Society of Heating,
Refrigerating and Air-Conditioning Engineers. It is the primary technical
standards body for HVAC systems referenced across Canada.
BC Municipal HVAC Technician Exam Guide | Page 2 of 39
,11. What is the difference between R-22 and R-410A?
ANSWER : R-22 is an HCFC refrigerant that is ozone-depleting and
was phased out in Canada by 2020. R-410A is an HFC refrigerant with
no ozone depletion potential (ODP=0), higher operating pressures, and
better energy efficiency, though it has a higher GWP.
12. What is the critical temperature of a refrigerant?
ANSWER : The critical temperature is the temperature above which a
substance cannot exist as a liquid, regardless of the pressure applied.
Above the critical temperature, the refrigerant remains a gas.
13. What is latent heat?
ANSWER : Latent heat is the heat absorbed or released during a phase
change (e.g., liquid to vapour) without a change in temperature. In
refrigeration, latent heat of vaporization is the heat absorbed when
refrigerant evaporates.
14. What is sensible heat?
ANSWER : Sensible heat is heat that causes a change in temperature
of a substance without changing its phase. It is measurable with a
thermometer, unlike latent heat.
15. What is the Coefficient of Performance (COP) of a refrigeration
system?
ANSWER : COP is the ratio of useful cooling (heat removed) to the
work input (energy consumed by the compressor). COP = Q_evap /
W_compressor. A higher COP indicates greater efficiency.
16. What refrigerant is commonly used in commercial refrigeration
(walk-in coolers) in BC?
ANSWER : R-404A and R-134a are common in commercial
refrigeration. However, due to high GWP regulations, R-448A and R-
449A are increasingly used as lower-GWP retrofits.
BC Municipal HVAC Technician Exam Guide | Page 3 of 39
, 17. What is the purpose of a filter-drier in a refrigeration system?
ANSWER : A filter-drier removes moisture and contaminants from the
refrigerant circuit. Moisture can cause acid formation and freeze at the
expansion device, so the drier contains desiccant materials (silica gel or
molecular sieve) to absorb it.
18. What is a sight glass used for in HVAC/R systems?
ANSWER : A sight glass allows a technician to visually inspect the
refrigerant flow. Bubbles in the sight glass indicate insufficient refrigerant
charge or a restriction upstream. A moisture indicator changes colour if
moisture is present.
19. What is refrigerant migration?
ANSWER : Refrigerant migration occurs when refrigerant migrates from
the high-pressure side to the compressor crankcase during the off-cycle,
mixing with the oil. On startup, floodback can damage the compressor
due to liquid slugging.
20. What is 'liquid slugging' and why is it harmful?
ANSWER : Liquid slugging occurs when liquid refrigerant or oil enters
the compressor cylinder. Since liquids are incompressible, this can crack
valve plates, pistons, or the compressor body, causing catastrophic
failure.
21. What does the term 'saturation temperature' mean?
ANSWER : Saturation temperature is the temperature at which a
refrigerant changes state (liquid to vapour or vice versa) at a specific
pressure. It is read from a pressure-temperature (P-T) chart for a given
refrigerant.
22. What is an azeotrope refrigerant blend?
BC Municipal HVAC Technician Exam Guide | Page 4 of 39
