Understanding Refrigerant Properties and Types

What is the bubble point used for in refrigerant systems?

• Charging by suction or evaporator superheat

• Charging by condenser subcooling

• Measuring the temperature glide

• Determining the refrigerant's flammability

Which series of refrigerants are near azeotropic blends that can leak at uneven rates?

• R-300 series

• R-400 series

• R-500 series

• R-600 series

What is the proper method for charging R-400 series blended refrigerants?

• Weigh the refrigerant into the low side as a vapor

• Weigh the refrigerant into the high side as a liquid

• Add refrigerant as a gas into the high side

• Add refrigerant as a liquid into the low side

Which refrigerant is known for having a high-temperature glide and may experience fractionation?

• R-134a

• R-407C

• R-410A

• R-717

What is the pressure range for medium-pressure refrigerants at a liquid-phase temperature of 104°F?

• 30 psig or lower

• Between 30 psig & 155 psig

• Between 155 psig & 340 psig

• Over 340 psig

Which of the following is an example of a low-pressure refrigerant?

• HFC-134a

• HCFC-22

• CFC-11

• CO2 (R-744)

What is the EPA's stance on substitute refrigerants for retrofitting systems?

• EPA approves direct drop-in replacements for R-22

• Only EPA-approved substitutes can be used

• Any refrigerant can be used as a substitute

• EPA does not regulate substitute refrigerants

Which refrigerant is classified as a very high-pressure refrigerant at 104°F?

• HFC-245fa

• HFC-407C

• CO2 (R-744)

• HFO-1234yf

Why must equipment be designed to handle certain refrigerants?

• Due to their color

• Due to their flammability

• Due to their cost

• Due to their availability

What is the concern with using blended refrigerants in systems that develop a leak?

• They are more expensive

• They can cause corrosion

• They may fractionate

• They are less efficient