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EPA 608 NEC 2023

EPA 608 Type 3 Exam Practice Test 1

Free EPA 608 Type III Exam Practice Test 1. 25 questions covering water circulation during chiller evacuation, refrigerant recovery sequence (liquid then vapor), hydrostatic tube testing, purge compressor location, evaporator charging valve as lowest access point, liquid charging under vacuum, idle system pressure requirements, rupture disk location on evaporator, incomplete evacuation effects, maximum recovery pressure for low-pressure chillers, R-11 CFC properties and phase-out, why low-pressure systems allow air ingress, Type III certification scope, centrifugal compressor principles, high-efficiency purge unit operation, EPA recovery requirements, R-123 as HCFC replacement, surge in centrifugal compressors, oil compatibility with R-123, comfort cooling leak threshold, rupture disk bursting procedure, ASHRAE Standard 15 monitoring, leak detection methods, variable inlet guide vanes, and R-245fa as HFC replacement.

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The EPA 608 certification is required by law for any technician who purchases or handles refrigerants. It covers safe handling, leak detection, recovery, and environmental regulations.

Type I covers small appliances (≤5 lbs refrigerant), Type II covers high-pressure systems, Type III covers low-pressure systems, and Universal covers all three. Most HVAC technicians pursue Universal certification.

You must score at least 70% on each section of the exam. The Universal exam has four parts: core, Type I, Type II, and Type III.

Key facts for Type III systems: Low-pressure refrigerant systems (R-11, R-123) operate below atmospheric pressure — any leak allows air to enter, not refrigerant to escape. The purge unit removes air (non-condensables) that collect at the top of the condenser. The rupture disk is mounted on the evaporator and bursts at 15 PSIG to prevent catastrophic failure. Maximum recovery pressure for low-pressure chillers is 10 PSIG — never exceed this or you risk bursting the rupture disk.

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EPA 608 Type 3 Exam Practice Test 1 — Question List

Question 1: The purpose of circulating water during the evacuation chiller refrigeration system is to …………..

Prevent the leakage of refrigerant to atmosphere
Prevent the freezing of water
Prevent the leakage of the air
Prevent freezing of refrigerant

Question 2: What should be done after recovering liquid refrigerant from refrigeration system?

Recover the vapour refrigerant
Remove the moisture in the system
Remove the oil from the system
Purge the system with pressurized nitrogen

Question 3: The hydrostatic test is used to check ………………….. within a chiller?

Moisture leaks
Tubing leaks
Compressor failure
Air leaks

Question 4: The purge compressor is typically connected on top of ………………. In low pressure chiller refrigeration system.

Condenser
Oil separator
Chiller
Purge drum

Question 5: Which of the following is the lowest access point on the low pressure centrifugal air-conditioning unit?

The evaporator charging valve
The condenser service valve
The purge unit exhaust valve
The chiller exhaust valve

Question 6: If the liquid charging into the refrigeration system is under 29 Hg vacuum then ………………….

The charging time increases
The water in the system freezes
The refrigerant may freeze in the system
The vapour in the system freezes

Question 7: In the idle low pressure system the lowest pressure that should be maintained is slightly above than ………………………

Atmospheric pressure
15 PSIG
Refrigerant tank pressure

Question 8: In a low pressure refrigeration system the rupture disk is connected to ………………..

Evaporator
Condenser
Receiver
Liquid pump

Question 9: What will happen if the refrigeration system is not evacuated fully?

Compressor head pressure rises
Moisture still remains in the system
Refrigerant vapour exists in the system
Evaporator coil may fail

Question 10: What is the maximum pressure setting of a recovery unit which is used to evacuate the refrigerant from low pressure chillier?

5 PSIG
10 PSIG
15 PSIG
20 PSIG

Question 11: What type of refrigerant is R-11 (CFC-11) and when was it phased out of production?

R-11 is an HFC with zero ozone depletion — still being produced today
R-11 is a CFC with ODP=1.0 — production was banned after December 31, 1995
R-11 is an HCFC — phased out in 2010 along with R-22
R-11 is a natural refrigerant — it is not regulated under Section 608

Question 12: What type of refrigerant is R-11 (CFC-11) and when was it phased out of production?

R-11 is an HFC with zero ozone depletion — still being produced today
R-11 is a CFC with ODP=1.0 — production was banned after December 31, 1995
R-11 is an HCFC — phased out in 2010 along with R-22
R-11 is a natural refrigerant — it is not regulated under Section 608

Question 13: Why does a low-pressure refrigeration system allow air to enter through leaks rather than allowing refrigerant to escape?

Low-pressure systems use special check valves that only allow one-way flow
Low-pressure systems operate below atmospheric pressure — outside air pressure pushes air inward through any leak
The refrigerant in low-pressure systems is too heavy to escape through small leaks
Low-pressure systems are completely sealed and neither air nor refrigerant can enter or exit

Question 14: Why does a low-pressure refrigeration system allow air to enter through leaks rather than allowing refrigerant to escape?

Low-pressure systems use special check valves that only allow one-way flow
Low-pressure systems operate below atmospheric pressure — outside air pressure pushes air inward through any leak
The refrigerant in low-pressure systems is too heavy to escape through small leaks
Low-pressure systems are completely sealed and neither air nor refrigerant can enter or exit

Question 15: Which type of EPA 608 certification is required to service low-pressure refrigerant systems such as centrifugal chillers using R-11 or R-123?

Type I certification — because chillers use small amounts of refrigerant
Type III certification — covers low-pressure sub-atmospheric refrigerant systems
Type II certification — R-11 is a high-pressure refrigerant
No certification needed — large chillers are exempt from EPA Section 608

Question 16: Which type of EPA 608 certification is required to service low-pressure refrigerant systems such as centrifugal chillers using R-11 or R-123?

Type I certification — because chillers use small amounts of refrigerant
Type III certification — covers low-pressure sub-atmospheric refrigerant systems
Type II certification — R-11 is a high-pressure refrigerant
No certification needed — large chillers are exempt from EPA Section 608

Question 17: How does a centrifugal compressor raise refrigerant pressure in a low-pressure chiller?

A centrifugal compressor uses pistons to compress refrigerant in a cylinder
A centrifugal compressor uses a rotating impeller to accelerate vapor; the diffuser converts velocity into pressure
A centrifugal compressor uses a scroll mechanism that traps and compresses refrigerant pockets
A centrifugal compressor uses electromagnetic force to compress refrigerant directly

Question 18: How does a centrifugal compressor raise refrigerant pressure in a low-pressure chiller?

A centrifugal compressor uses pistons to compress refrigerant in a cylinder
A centrifugal compressor uses a rotating impeller to accelerate vapor; the diffuser converts velocity into pressure
A centrifugal compressor uses a scroll mechanism that traps and compresses refrigerant pockets
A centrifugal compressor uses electromagnetic force to compress refrigerant directly

Question 19: What is the main advantage of a high-efficiency purge unit over a standard purge unit on a low-pressure chiller?

High-efficiency purge units are faster — they remove air more quickly than standard units
High-efficiency purge units recover refrigerant from the air/refrigerant mixture before venting, reducing emissions
High-efficiency purge units can run without electricity — they are gravity-operated
High-efficiency purge units also remove moisture from the system during purging

Question 20: What is the main advantage of a high-efficiency purge unit over a standard purge unit on a low-pressure chiller?

High-efficiency purge units are faster — they remove air more quickly than standard units
High-efficiency purge units recover refrigerant from the air/refrigerant mixture before venting, reducing emissions
High-efficiency purge units can run without electricity — they are gravity-operated
High-efficiency purge units also remove moisture from the system during purging

Question 21: What is the EPA required recovery vacuum level for low-pressure refrigerant equipment (R-11, R-123) before opening the system for service?

The system does not need to be evacuated — just reduce pressure to 0 psig before opening
Evacuate to 25 mm Hg absolute (approximately 29 in. Hg vacuum) before opening the system
Evacuate to 15 in. Hg vacuum — the same requirement as for large high-pressure systems
There is no vacuum requirement for low-pressure systems since they already operate below atmospheric

Question 22: What is the EPA required recovery vacuum level for low-pressure refrigerant equipment (R-11, R-123) before opening the system for service?

The system does not need to be evacuated — just reduce pressure to 0 psig before opening
Evacuate to 25 mm Hg absolute (approximately 29 in. Hg vacuum) before opening the system
Evacuate to 15 in. Hg vacuum — the same requirement as for large high-pressure systems
There is no vacuum requirement for low-pressure systems since they already operate below atmospheric

Question 23: What makes R-123 (HCFC-123) a better replacement for R-11 from an environmental standpoint?

R-123 is better because it is an HFC with zero ozone depletion potential
R-123 has a much lower ODP (0.02 vs 1.0 for R-11) and much lower GWP (77 vs 4,750)
R-123 operates at higher pressures which makes it safer to handle than R-11
R-123 does not require EPA certification to purchase or use

Question 24: What makes R-123 (HCFC-123) a better replacement for R-11 from an environmental standpoint?

R-123 is better because it is an HFC with zero ozone depletion potential
R-123 has a much lower ODP (0.02 vs 1.0 for R-11) and much lower GWP (77 vs 4,750)
R-123 operates at higher pressures which makes it safer to handle than R-11
R-123 does not require EPA certification to purchase or use

Question 25: What is "surge" in a centrifugal compressor and what causes it?

Surge is when the compressor overheats due to excessive load and trips on thermal protection
Surge is the reversal of refrigerant flow in the centrifugal compressor that occurs at very low load conditions
Surge is a pressure drop in the evaporator that causes the refrigerant to flash prematurely
Surge refers to a sudden spike in electrical current when the compressor starts

Question 26: What is "surge" in a centrifugal compressor and what causes it?

Surge is when the compressor overheats due to excessive load and trips on thermal protection
Surge is the reversal of refrigerant flow in the centrifugal compressor that occurs at very low load conditions
Surge is a pressure drop in the evaporator that causes the refrigerant to flash prematurely
Surge refers to a sudden spike in electrical current when the compressor starts

Question 27: What type of lubricating oil is required in low-pressure centrifugal chillers using R-123?

Mineral oil — the same oil used in older R-11 systems
Alkylbenzene (AB) oil — compatible with R-123 and stable at low chiller temperatures
POE (polyolester) oil — required for all HFC and HCFC refrigerants
Synthetic oil — any brand of synthetic lubricant can be used

Question 28: What type of lubricating oil is required in low-pressure centrifugal chillers using R-123?

Mineral oil — the same oil used in older R-11 systems
Alkylbenzene (AB) oil — compatible with R-123 and stable at low chiller temperatures
POE (polyolester) oil — required for all HFC and HCFC refrigerants
Synthetic oil — any brand of synthetic lubricant can be used

Question 29: A large R-123 centrifugal chiller used for building air conditioning has a 2,000 lb refrigerant charge. What is the annual leak rate threshold that triggers a mandatory repair requirement?

35% per year — large systems get a higher threshold than small systems
15% per year — comfort cooling systems (including large chillers) must repair leaks exceeding 15% annually
50% per year — chillers are exempt from strict leak requirements due to their size
There is no threshold — leak repair is voluntary for systems over 1,000 lbs

Question 30: A large R-123 centrifugal chiller used for building air conditioning has a 2,000 lb refrigerant charge. What is the annual leak rate threshold that triggers a mandatory repair requirement?

35% per year — large systems get a higher threshold than small systems
15% per year — comfort cooling systems (including large chillers) must repair leaks exceeding 15% annually
50% per year — chillers are exempt from strict leak requirements due to their size
There is no threshold — leak repair is voluntary for systems over 1,000 lbs

Question 31: When a rupture disk on a low-pressure chiller bursts and releases refrigerant into the equipment room, what must happen before the system can be returned to service?

Simply patch the rupture disk with tape and recharge — the system will continue normally
Ventilate the area, replace the rupture disk, inspect for contamination, pull vacuum, then recharge
Immediately seal the system and pump it down before replacing the disk
Wait 24 hours for remaining refrigerant to evaporate, then replace disk without evacuation

Question 32: When a rupture disk on a low-pressure chiller bursts and releases refrigerant into the equipment room, what must happen before the system can be returned to service?

Simply patch the rupture disk with tape and recharge — the system will continue normally
Ventilate the area, replace the rupture disk, inspect for contamination, pull vacuum, then recharge
Immediately seal the system and pump it down before replacing the disk
Wait 24 hours for remaining refrigerant to evaporate, then replace disk without evacuation

Question 33: According to ASHRAE Standard 15, what refrigerant monitoring requirement applies to equipment rooms containing R-123 centrifugal chillers?

No monitoring is required — R-123 is too heavy to build up in the air
A refrigerant detector with alarm and emergency ventilation is required in all equipment rooms per ASHRAE Standard 15
Only sprinkler systems are required — refrigerant detection is optional
ASHRAE Standard 15 only applies to flammable refrigerants — not R-123

Question 34: According to ASHRAE Standard 15, what refrigerant monitoring requirement applies to equipment rooms containing R-123 centrifugal chillers?

No monitoring is required — R-123 is too heavy to build up in the air
A refrigerant detector with alarm and emergency ventilation is required in all equipment rooms per ASHRAE Standard 15
Only sprinkler systems are required — refrigerant detection is optional
ASHRAE Standard 15 only applies to flammable refrigerants — not R-123

Question 35: Which leak detection methods are effective for detecting R-11 leaks in a low-pressure centrifugal chiller?

Soap bubbles only — electronic detectors are too sensitive for large chiller systems
Electronic leak detector and halide torch — both detect R-11 since it is a CFC containing chlorine
Nitrogen pressure test — pressurize to 100 PSIG and look for pressure drop
Electronic detector only — R-11 is too heavy for halide torch detection

Question 36: Which leak detection methods are effective for detecting R-11 leaks in a low-pressure centrifugal chiller?

Soap bubbles only — electronic detectors are too sensitive for large chiller systems
Electronic leak detector and halide torch — both detect R-11 since it is a CFC containing chlorine
Nitrogen pressure test — pressurize to 100 PSIG and look for pressure drop
Electronic detector only — R-11 is too heavy for halide torch detection

Question 37: What is the function of variable inlet guide vanes (IGVs) on a centrifugal chiller compressor?

IGVs control the amount of oil injected into the compressor bearings during operation
IGVs adjust the angle of refrigerant entering the impeller to modulate capacity and prevent surge
IGVs are emergency safety valves that close when pressure becomes too high
IGVs control the speed of the compressor motor using variable frequency

Question 38: What is the function of variable inlet guide vanes (IGVs) on a centrifugal chiller compressor?

IGVs control the amount of oil injected into the compressor bearings during operation
IGVs adjust the angle of refrigerant entering the impeller to modulate capacity and prevent surge
IGVs are emergency safety valves that close when pressure becomes too high
IGVs control the speed of the compressor motor using variable frequency

Question 39: What is R-245fa, and why is it considered a long-term alternative for low-pressure centrifugal chiller applications?

R-245fa is a CFC refrigerant that was phased out in 1995 along with R-11
R-245fa is an HFC with zero ODP — a long-term low-pressure refrigerant with no Montreal Protocol restrictions
R-245fa is a natural refrigerant (propane blend) used in small low-temperature applications
R-245fa is a high-pressure refrigerant similar to R-410A, not used in centrifugal chillers

Question 40: What is R-245fa, and why is it considered a long-term alternative for low-pressure centrifugal chiller applications?

R-245fa is a CFC refrigerant that was phased out in 1995 along with R-11
R-245fa is an HFC with zero ODP — a long-term low-pressure refrigerant with no Montreal Protocol restrictions
R-245fa is a natural refrigerant (propane blend) used in small low-temperature applications
R-245fa is a high-pressure refrigerant similar to R-410A, not used in centrifugal chillers

Study Tip: The EPA 608 exam is closed book. Memorize: recovery is required before opening any refrigerant system. Venting refrigerant is illegal. Know the ODP and GWP values for R-22, R-410A, R-134a, R-32, and R-454B.

EXAM CARD EPA 608

Questions40

Time limit45 min

Pass score70%

RegulationEPA Section 608

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: EPA Section 608 (40 CFR Part 82)