Exam Practice Questions And Correct

EPA Section 608 Type III Certification Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What type of appliance is considered low-pressure under EPA Section

608?

• Small window air conditioner
• Residential refrigerator
• Centrifugal chiller
• Split-system heat pump

Low-pressure appliances operate below 30 psig; centrifugal chillers use R-11, R-123, etc., which are low-pressure refrigerants.

• What is the typical pressure of R-123 at 80°F?
• 118 psig 1 / 4

• 124 psig
• 15 psig
• 195 psig

R-123 has a low vapor pressure of about 124 psig at 80°F, consistent with low-pressure systems.

• When evacuating a low-pressure system, the required vacuum level is

measured in:

• Inches of water column
• Inches of mercury above zero
• Inches of mercury vacuum
• Microns absolute pressure

EPA mandates evacuation requirements in inches of mercury vacuum for Type III.

• What is the maximum allowable leak rate for low-pressure appliances?
• 10% per year
• 15% per year
• 10% per year
• 30% per year

The EPA leak rate threshold for low-pressure systems is 10% per year.

• Which refrigerant is commonly used in low-pressure chillers?

A. R-410A

B. R-22

C. R-123 2 / 4

D. R-404A

R-123 is widely used in centrifugal chillers as a low-pressure refrigerant.

• What is the purpose of a purge unit on a low-pressure system?
• Add oil
• Control temperature
• Remove non-condensables
• Add refrigerant

Purge units remove air and other non-condensable gases from the chiller to maintain efficiency.

• What can cause high system pressure in a low-pressure chiller?
• Low water temperature
• Excessive air in system
• Low refrigerant charge
• Faulty TXV

Air and other non-condensables raise condenser pressure in low- pressure systems.

• What is a key indication of non-condensables in a low-pressure chiller?
• High suction pressure
• High condenser pressure
• Low evaporator pressure
• Low oil pressure

Non-condensables collect in the condenser, increasing pressure. 3 / 4

• Before recovering refrigerant from a low-pressure chiller, the water

box should be:

• Left open
• Isolated and drained
• Heated
• Pressurized

Isolating and draining prevents water contamination or pressure damage during recovery.

• What refrigerant state is typically recovered from low-pressure

systems?

• Liquid only
• Vapor only
• Both liquid and vapor
• None

Recovery occurs from both liquid and vapor phases to remove all refrigerant.

• When is refrigerant recovered as vapor from a low-pressure

system?

• When liquid is exhausted
• When system pressure is below atmospheric
• When the chiller is running
• When oil is added

Below atmospheric pressure, only vapor recovery is possible.

• / 4