LOW GWP REFRIGERANT SAFETY EXAM AND
PRACTICE EXAM 2026/2027 WITH ACTUAL
CORRECT QUESTIONS AND VERIFIED
DETAILED ANSWERS |CURRENTLY TESTING
QUESTIONS AND SOLUTIONS|ALREADY
GRADED A+|NEWEST |BRAND NEW VERSION!!|
|JUST RELEASED
What is temperature glide?
The range of boiling (or condensing) temperatures at a given pressure.
What is the temperature glide range?
From 0.2°F to 16°F.
What is needed to calculate superheat and subcooling?
The low and high side pressures and the liquid and vapor line temperatures.
How can system pressures be converted to saturation temperatures?
Using a P/T chart.
What is the significance of proper airflow in a condenser?
It ensures proper airflow and heat transfer.
What is the impact of adding sensible heat versus latent heat?
Adding sensible heat causes a change in temperature, while adding latent heat causes a
change in state.
What are zeotropic and near-azeotropic refrigerants?
1|Page
,Refrigerants like R-407C and R-422D that have two pressure columns on a
pressure/temperature chart, using dew point (vapor) and bubble point (liquid) for
calculations.
How is superheat defined in the context of refrigerants?
Superheat is the temperature of the vapor above its boiling point at a given pressure.
What is the suction pressure and vapor line temperature for R-422D?
Suction Pressure: 74 psig; Vapor line Temp: 60°F.
What is subcooling in refrigerants?
Subcooling is the process of cooling a liquid refrigerant below its boiling point at a given
pressure.
What is the discharge pressure and liquid line temperature for R-422D?
Discharge Pressure: 281 psig; Liquid line Temp: 105°F.
What is the midpoint when sizing system components for blended refrigerants?
The midpoint is the average temperature of a coil (either condenser or evaporator) in a
system charged with a blended refrigerant.
How do you calculate the evaporator midpoint for a blended refrigerant?
Multiply the bubble temperature by 0.40 and the dew temperature by 0.60, then add the
results together.
What is the formula for calculating the evaporator midpoint using R-422D at 84 psig?
Bubble point = 45°F, Dew point = 51°F; Midpoint = (45°F × 0.40) + (51°F × 0.60) = 48.6°F.
How do you calculate the condenser midpoint for a blended refrigerant?
Add the dew and bubble temperatures together, then divide by 2.
What is the midpoint for R-407C at 196 psig?
2|Page
, Dew point = 100°F, Bubble point = 90.8°F; Midpoint = (100 + 90.8) ÷ 2 = 95.4°F.
What does AHRI Guideline N specify for refrigerant container colors?
All refrigerant containers should be light-green/grey (RAL 7044) and existing colors should
transition to this standard by 2020.
What must be included on containers of flammable refrigerants?
A red band on the top of the container.
What does a lowercase letter designation in refrigerants indicate?
It indicates an isomer, which has the same formula and molecular weight but different
arrangements and properties.
What does an uppercase letter designation in refrigerants signify?
It signifies that refrigerant blends are composed of the same refrigerants but with different
percentages.
What are Hydrofluorocarbons (HFCs)?
Refrigerants containing hydrogen, fluorine, and carbon that do not deplete the ozone layer
and often have high global warming potentials (GWP) over 1,500.
What are Hydrofluoroolefins (HFOs)?
Chemically similar to HFCs, HFOs have low GWP and are mildly flammable, used in
various applications like automotive air-conditioning.
What is the trend regarding HFC/HFO blends in the HVACR industry?
They are becoming more common due to their low GWP and application-specific uses.
What are hydrocarbons (HCs) in the context of refrigerants?
Refrigerants containing hydrogen and carbon, classified as highly flammable (A3 safety
group) and often referred to as natural refrigerants.
3|Page
PRACTICE EXAM 2026/2027 WITH ACTUAL
CORRECT QUESTIONS AND VERIFIED
DETAILED ANSWERS |CURRENTLY TESTING
QUESTIONS AND SOLUTIONS|ALREADY
GRADED A+|NEWEST |BRAND NEW VERSION!!|
|JUST RELEASED
What is temperature glide?
The range of boiling (or condensing) temperatures at a given pressure.
What is the temperature glide range?
From 0.2°F to 16°F.
What is needed to calculate superheat and subcooling?
The low and high side pressures and the liquid and vapor line temperatures.
How can system pressures be converted to saturation temperatures?
Using a P/T chart.
What is the significance of proper airflow in a condenser?
It ensures proper airflow and heat transfer.
What is the impact of adding sensible heat versus latent heat?
Adding sensible heat causes a change in temperature, while adding latent heat causes a
change in state.
What are zeotropic and near-azeotropic refrigerants?
1|Page
,Refrigerants like R-407C and R-422D that have two pressure columns on a
pressure/temperature chart, using dew point (vapor) and bubble point (liquid) for
calculations.
How is superheat defined in the context of refrigerants?
Superheat is the temperature of the vapor above its boiling point at a given pressure.
What is the suction pressure and vapor line temperature for R-422D?
Suction Pressure: 74 psig; Vapor line Temp: 60°F.
What is subcooling in refrigerants?
Subcooling is the process of cooling a liquid refrigerant below its boiling point at a given
pressure.
What is the discharge pressure and liquid line temperature for R-422D?
Discharge Pressure: 281 psig; Liquid line Temp: 105°F.
What is the midpoint when sizing system components for blended refrigerants?
The midpoint is the average temperature of a coil (either condenser or evaporator) in a
system charged with a blended refrigerant.
How do you calculate the evaporator midpoint for a blended refrigerant?
Multiply the bubble temperature by 0.40 and the dew temperature by 0.60, then add the
results together.
What is the formula for calculating the evaporator midpoint using R-422D at 84 psig?
Bubble point = 45°F, Dew point = 51°F; Midpoint = (45°F × 0.40) + (51°F × 0.60) = 48.6°F.
How do you calculate the condenser midpoint for a blended refrigerant?
Add the dew and bubble temperatures together, then divide by 2.
What is the midpoint for R-407C at 196 psig?
2|Page
, Dew point = 100°F, Bubble point = 90.8°F; Midpoint = (100 + 90.8) ÷ 2 = 95.4°F.
What does AHRI Guideline N specify for refrigerant container colors?
All refrigerant containers should be light-green/grey (RAL 7044) and existing colors should
transition to this standard by 2020.
What must be included on containers of flammable refrigerants?
A red band on the top of the container.
What does a lowercase letter designation in refrigerants indicate?
It indicates an isomer, which has the same formula and molecular weight but different
arrangements and properties.
What does an uppercase letter designation in refrigerants signify?
It signifies that refrigerant blends are composed of the same refrigerants but with different
percentages.
What are Hydrofluorocarbons (HFCs)?
Refrigerants containing hydrogen, fluorine, and carbon that do not deplete the ozone layer
and often have high global warming potentials (GWP) over 1,500.
What are Hydrofluoroolefins (HFOs)?
Chemically similar to HFCs, HFOs have low GWP and are mildly flammable, used in
various applications like automotive air-conditioning.
What is the trend regarding HFC/HFO blends in the HVACR industry?
They are becoming more common due to their low GWP and application-specific uses.
What are hydrocarbons (HCs) in the context of refrigerants?
Refrigerants containing hydrogen and carbon, classified as highly flammable (A3 safety
group) and often referred to as natural refrigerants.
3|Page
