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EPA 608 NEC 2023

EPA 608 Type 3 Exam Practice Test 5

Free EPA 608 Type III Exam Practice Test 5. 25 questions covering centrifugal chiller charging through evaporator valve, filter drier replacement requirement, R-410A recovery cylinder pressure rating, nitrogen to prevent moisture freeze during evacuation, pressure reduction causing liquid to vaporize, liquid recovered before vapor, 30-day leak repair deadline, 35% commercial refrigeration leak threshold, 50 lb system exemption from mandatory repair, rupture disk relief pressure, R-11 CFC ODP and GWP properties, sub-atmospheric operation defining Type III systems, centrifugal chiller capacity for large buildings, surge at low load conditions, hot gas bypass purpose, accumulator after evaporator, ASHRAE Standard 15 detector alarm requirements, 25 mm Hg recovery level, AB oil for R-123 and R-11 retrofit, R-11 vs R-123 GWP comparison, low-loss fittings on service hoses, chiller startup checklist, evaporator freeze detection, pre-service vacuum requirement, and comfort cooling chilled water systems.

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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 this test: Centrifugal chillers are charged through the evaporator charging valve — the lowest access point in the system. Always replace the filter drier whenever a low-pressure system is opened. A low-pressure system leak means the system loses charge less than 50 lbs — these systems are exempt from mandatory leak repair under EPA Section 608. The rupture disk in a low-pressure chiller is set to relieve at 15 PSIG.

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EPA 608 Type 3 Exam Practice Test 5 — Question List

Question 1: The centrifugal compressors should be charged through ………………..

Evaporator charging valve
Condenser suction line
Liquid line
Vapor line

Question 2: When a low pressure refrigerant system is opened for service ………………… should be replaced compulsory.

Filter drier
Compressor
Expansion valve
Condenser tube

Question 3: What should be the minimum capacity of R-410A refrigerant recovery tanks?

400 psig
200 psig
350 psig
120 psig

Question 4: If the refrigeration contains large amount of moisture, to prevent freezing of moisture during evacuation the system pressure can be increased with …………. Gas

Nitrogen
Oxygen
Hydrogen
Argon

Question 5: If the pressure in the refrigeration circuit is lowered then it causes the refrigerant …………….

Liquid to vaporize
Liquid to freeze
Vapor to liquid
Vapor to leak.

Question 6: Which refrigerant you must recover first from the refrigeration system?

Liquid refrigerant
Vapor refrigerant

Question 7: In maximum how many days the discovered leak should be repaired as per EPA?

15 days
30 days
45 days
60 days

Question 8: In commercial and industrial refrigeration systems, if the leak percentage increases more than ………….. of the charge per year must be removed.

30 %
35 %
50 %
15 %

Question 9: The leaks in a refrigeration system contains ……………. refrigerant need not be repaired as per EPA.

Less than 50 pounds
Greater than 50 pounds
Less than 100 pounds
Greater than 100 pounds

Question 10: What is the rupture disk relief pressure in the low pressure refrigeration system?

10 psig
15 psig
20 psig
18 psig

Question 11: R-11 is classified as a CFC. What does CFC stand for, and what does R-11's ODP of 1.0 mean for the ozone layer?

CFC means Carbon-Fluoride Compound; ODP 1.0 means R-11 has the lowest possible ozone damage
CFC means Chlorofluorocarbon; ODP 1.0 means R-11 is the reference standard for maximum ozone depletion
CFC means Cold Fluid Coolant; ODP 1.0 is a pressure rating for the refrigerant cylinder
CFC means Carbon-Fluorocarbon; ODP 1.0 means R-11 has been 100% replaced by R-123

Question 12: How do you know if a refrigerant system requires Type III EPA certification, rather than Type II?

Systems using more than 1,000 lbs of refrigerant require Type III; smaller systems require Type II
If the evaporator operates at sub-atmospheric pressure (vacuum), it is Type III; if above atmospheric, it is Type II
Type III is required for all systems in buildings taller than 10 stories
Type III is required when the refrigerant is recovered using a vacuum pump; Type II uses a pressure method

Question 13: A 20-story office building requires 800 tons of cooling capacity. Why is a centrifugal chiller with R-123 more appropriate than multiple smaller split systems for this application?

Multiple split systems are always more efficient — smaller units use less energy than large chillers
A single centrifugal chiller is more efficient (lower kW/ton), requires less space, and is more cost-effective to operate and maintain than hundreds of individual split systems
Centrifugal chillers are required by building code for buildings over 10 stories — it is not an efficiency choice
Centrifugal chillers are chosen only because R-123 cannot be used in split systems

Question 14: Under what operating condition is a centrifugal chiller most likely to surge?

At maximum full load on the hottest day of the year — when demand is highest
At very low cooling demand (10–15% load) on cool days — when refrigerant flow falls below the minimum stable level for the centrifugal impeller
During startup only — surge cannot occur during steady-state operation
When outdoor humidity is very high — moisture in the refrigerant triggers surge

Question 15: If a centrifugal chiller's hot gas bypass valve fails in the CLOSED position, what risk does this create?

The chiller will overheat — hot gas bypass normally cools the compressor motor
The chiller will surge at low load conditions — without hot gas bypass, there is nothing to prevent surge below the minimum stable flow point
The chiller will freeze the chilled water — bypass prevents freezing in the evaporator
No risk — hot gas bypass is a backup system that is rarely needed in normal operation

Question 16: What is the function of a suction accumulator in a refrigeration system, and why is it located between the evaporator and the compressor?

The accumulator stores extra refrigerant charge for use when more cooling capacity is needed
The accumulator separates liquid from suction vapor, preventing liquid refrigerant from entering and damaging the compressor
The accumulator measures the amount of refrigerant in the system for charging purposes
The accumulator cools the refrigerant vapor before it reaches the compressor to improve efficiency

Question 17: According to ASHRAE Standard 15, what must happen automatically when the refrigerant detector in an R-123 chiller room detects refrigerant above the alarm setpoint?

The detector notifies the fire department only — building staff must manually start the ventilation fans
Both an audible alarm and emergency ventilation (exhaust fans) must activate automatically without requiring manual action
The refrigerant detector only logs the event — manual response is the building owner's responsibility
The chiller automatically shuts down — no ventilation or alarm is required by Standard 15

Question 18: A technician has pulled a vacuum on an R-123 chiller to 30 mm Hg absolute. Has the EPA recovery requirement been met?

Yes — 30 mm Hg absolute is close enough to 25 mm Hg; a 5 mm difference is within tolerance
No — the requirement is 25 mm Hg absolute or less; at 30 mm Hg the vacuum is not deep enough and recovery must continue
Yes — 30 mm Hg is deeper than 25 mm Hg because higher numbers mean better vacuum
The 25 mm Hg requirement only applies when opening the system; for normal service it is not needed

Question 19: After retrofitting an R-11 chiller to R-123, a technician notices that the evaporator is not performing as well as expected — leaving chilled water temperature is higher than setpoint. Oil logging in the evaporator is suspected. What is the most likely cause?

The R-123 charge is low — the system needs more refrigerant
Residual mineral oil from the R-11 system was not completely flushed — it has deposited on evaporator tubes, reducing heat transfer
R-123 is simply less efficient than R-11 — some performance loss is expected after retrofit
The condenser water flow rate is too low — this would cause poor evaporator performance

Question 20: A building owner is considering whether to retrofit their R-11 chillers to R-123 or replace them with new R-245fa chillers. From a GWP (global warming potential) standpoint, which refrigerant is best?

R-11 has the lowest GWP — newer refrigerants always have higher GWP
R-123 has the lowest GWP (77) — far better than R-245fa (1,030) or R-11 (4,750) for climate impact
All three refrigerants have the same GWP — GWP only applies to HFC refrigerants
R-245fa has the lowest GWP (0) — as an HFC it has no global warming impact

Question 21: What is the purpose of low-loss fittings on refrigerant service hoses, and are they required on Type III service hoses?

Low-loss fittings are only required on Type II high-pressure systems — Type III low-pressure does not need them
Low-loss fittings automatically seal when disconnected, preventing refrigerant release or air ingress; required on all refrigerant service hoses including Type III
Low-loss fittings reduce hose pressure drop — they are a performance feature, not a regulatory requirement
Low-loss fittings are used only on recovery cylinders — not on service manifold hoses

Question 22: Before starting a large R-123 centrifugal chiller after a seasonal shutdown, what is the MOST critical item to check?

Check the condenser water temperature — if it is too cold, the chiller may not start properly
Verify oil temperature is at least 100°F from the oil heater — cold oil with dissolved refrigerant will foam and destroy bearings on startup
Check the refrigerant charge level — insufficient charge is the most common startup problem
Test the emergency stop button — this is always the first item on any startup checklist

Question 23: Why must chilled water continue to circulate through the evaporator even while a low-pressure chiller is being evacuated for service?

Water circulation is needed to clean the evaporator tubes during evacuation
During deep evacuation, evaporator pressure drops so low that water can freeze in the tubes — circulation keeps water moving and warm enough to prevent ice formation
Water circulation maintains refrigerant pressure during evacuation so the vacuum pump works faster
Standing water would contaminate the refrigerant during evacuation — circulation prevents this

Question 24: After recovering refrigerant from a low-pressure chiller to 25 mm Hg absolute, the technician opens the system. Some air enters. Before recharging, what must happen?

Charge immediately — the small amount of air that entered during service is acceptable
Evacuate the system again to 25 mm Hg absolute to remove the air and moisture that entered before recharging
Purge with nitrogen first, then charge without pulling vacuum again
The system only needs vacuum before the first-ever charge — re-evacuation after service is not required

Question 25: A technician adds 180 lbs of R-123 to a 900 lb chiller over 12 months. The chiller provides air conditioning to an office building. What EPA obligations are triggered?

No obligations — 20% is below the 35% commercial refrigeration threshold
Repair within 30 days (20% exceeds 15% comfort cooling threshold) and maintain service records for 3 years (system over 50 lbs)
The technician must recover all refrigerant and shut down the chiller immediately
No obligations — R-123 is an HCFC and is exempt from EPA leak rate requirements

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

Questions25

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)