HVAC Refrigerant Recovery and Handling — Questions and Answers

Question 1: What EPA regulation requires technicians to recover refrigerants before servicing equipment?

Section 608 of the Clean Air Act (Correct answer)
Section 609 of the Clean Air Act
ASHRAE Standard 15
OSHA 29 CFR 1910

Correct answer: Section 608 of the Clean Air Act

Section 608 of the Clean Air Act prohibits the knowing venting of refrigerants and requires proper recovery before servicing stationary equipment.

Question 2: Which refrigerant is classified as an A1 safety group by ASHRAE?

R-32
R-410A (Correct answer)
R-290
R-600a

Correct answer: R-410A

R-410A is classified as A1 by ASHRAE, meaning it is low toxicity (A) and nonflammable (1), making it relatively safe for use.

Question 3: What is the minimum recovery efficiency required for systems with more than 200 lbs of refrigerant per EPA Section 608 rules?

80%
90%
95% (Correct answer)
99%

Correct answer: 95%

EPA Section 608 requires 95% recovery efficiency for systems containing more than 200 lbs of refrigerant when using recovery equipment manufactured after November 15, 1993.

Question 4: What does the term 'refrigerant reclaim' mean?

Removing refrigerant from equipment into a recovery cylinder
Reprocessing refrigerant to original purity standards (Correct answer)
Reusing refrigerant without processing
Transferring refrigerant between cylinders

Correct answer: Reprocessing refrigerant to original purity standards

Reclaim means reprocessing used refrigerant to the purity standards of ARI 700, essentially restoring it to virgin quality. This is distinct from recover (remove) or recycle (clean on-site).

Question 5: Which color identifies a recovery cylinder for R-410A refrigerant?

White with gray collar
Pink (rose) (Correct answer)
Light blue
Green

Correct answer: Pink (rose)

R-410A recovery cylinders are pink (rose) per the ARI/AHRI color-coding standard, helping technicians quickly identify the refrigerant type.

Question 6: What is the purpose of a refrigerant recovery machine's oil separator?

To filter moisture from the refrigerant
To separate compressor oil from recovered refrigerant (Correct answer)
To remove non-condensables from the cylinder
To measure refrigerant purity

Correct answer: To separate compressor oil from recovered refrigerant

The oil separator in a recovery machine removes compressor oil that may have mixed with the refrigerant during the recovery process, keeping the recovered refrigerant cleaner.

Question 7: What is the maximum fill level (by weight) for a recovery cylinder?

70%
80% (Correct answer)
90%
100%

Correct answer: 80%

Recovery cylinders must not be filled above 80% of their capacity by weight to allow for thermal expansion and prevent dangerous overpressure conditions.

Question 8: Which document must accompany refrigerant shipments and identifies the type and amount of refrigerant?

Material Safety Data Sheet (MSDS/SDS) (Correct answer)
Refrigerant transfer log
EPA technician certification card
Refrigerant purchase receipt

Correct answer: Material Safety Data Sheet (MSDS/SDS)

A Safety Data Sheet (SDS, formerly MSDS) must accompany refrigerant shipments. It provides hazard information, handling procedures, and emergency response details.

Question 9: What is 'push-pull' recovery method?

Using two recovery machines simultaneously
Connecting liquid and vapor valves to speed recovery
Recovering refrigerant in both liquid and vapor states simultaneously through separate hoses (Correct answer)
Alternating between recovery and recharge cycles

Correct answer: Recovering refrigerant in both liquid and vapor states simultaneously through separate hoses

The push-pull method uses both liquid and vapor hoses simultaneously — the recovery machine pulls vapor while system pressure pushes liquid — significantly speeding up recovery of large charges.

Question 10: Under EPA Section 608, who must be certified to purchase refrigerants in containers larger than 2 lbs?

Any licensed contractor
EPA Section 608 certified technicians only (Correct answer)
Both EPA 608 and state-licensed technicians
Only master HVAC technicians

Correct answer: EPA Section 608 certified technicians only

Since January 1, 2018, the EPA requires that technicians purchasing refrigerants in containers larger than 2 lbs be certified under Section 608, applying to all refrigerants including HFCs.

Question 11: What is a 'non-condensable' gas in a refrigerant system, and why is it harmful?

Moisture vapor that won't condense at operating pressures, causing corrosion
A gas like nitrogen or air that raises head pressure and reduces efficiency (Correct answer)
Refrigerant that has decomposed and cannot condense
Oil vapor that blocks the expansion device

Correct answer: A gas like nitrogen or air that raises head pressure and reduces efficiency

Non-condensables are gases (like air or nitrogen) that do not condense at normal operating pressures and temperatures. They raise head pressure, reduce heat transfer efficiency, and can cause high discharge temperatures.

Question 12: Which refrigerant replaced R-22 as the standard for new residential air conditioning systems?

R-134a
R-410A (Correct answer)
R-407C
R-32

Correct answer: R-410A

R-410A replaced R-22 as the standard refrigerant for new residential AC systems in the US, effective January 1, 2010, when new equipment using R-22 was banned.

Question 13: What is the GWP (Global Warming Potential) reference standard for refrigerant comparison?

Methane (CH4) = 1
Carbon dioxide (CO2) = 1 (Correct answer)
R-22 = 1
Water vapor = 1

Correct answer: Carbon dioxide (CO2) = 1

GWP is measured relative to CO2, which is set at 1. A refrigerant with GWP of 2,088 (like R-410A) traps 2,088 times more heat than CO2 over a 100-year period.

Question 14: What does the acronym 'HFC' stand for in refrigerant classification?

Hydrofluorocarbon (Correct answer)
Hydrochlorofluorocarbon
Hydrofluorochloride
High-Frequency Cooling

Correct answer: Hydrofluorocarbon

HFC stands for Hydrofluorocarbon. HFCs contain hydrogen, fluorine, and carbon, but no chlorine or bromine, so they have zero ozone depletion potential (ODP = 0).

Question 15: When should a refrigerant recovery cylinder be condemned and removed from service?

After 5 years of use
When the DOT-rated pressure is exceeded or physical damage is visible (Correct answer)
After being filled and emptied 10 times
When the weight exceeds the tare weight by 20%

Correct answer: When the DOT-rated pressure is exceeded or physical damage is visible

Recovery cylinders must be condemned when they show physical damage (dents, corrosion, leaks), when the DOT retest date has expired, or when pressure ratings have been exceeded. Safety comes first.

Question 16: What is the ODP (Ozone Depletion Potential) of R-410A?

0.05
0.50
1.00
0.00 (Correct answer)

Correct answer: 0.00

R-410A has an ODP of 0 because it contains no chlorine or bromine atoms, which are the elements that destroy stratospheric ozone. This is why it replaced R-22 (ODP = 0.05).

Question 17: Which recovery method is fastest for recovering large amounts of liquid refrigerant?

Vapor recovery only
Liquid recovery first, then vapor (Correct answer)
Vapor recovery with system running
Inert gas push method

Correct answer: Liquid recovery first, then vapor

Liquid recovery is much faster than vapor recovery because liquid is denser and flows more quickly. Best practice is to recover liquid first through the liquid line service valve, then recover remaining vapor.

Question 18: What pressure must be achieved in a system after recovery is complete per EPA Section 608?

0 psig (atmospheric pressure)
The required vacuum level depends on system size and compressor type (Correct answer)
5 inches of mercury vacuum
15 psig

Correct answer: The required vacuum level depends on system size and compressor type

EPA Section 608 establishes different required recovery levels based on equipment type and size. For example, systems with compressors larger than 200 HP must achieve 15 in. Hg vacuum; smaller systems have less stringent requirements.

Question 19: What information must be recorded in the refrigerant log for systems containing 50 lbs or more of refrigerant?

Only the date of service
Technician name, date, amount recovered/added, and reason for service (Correct answer)
Only the amount of refrigerant added
Just the EPA certification number

Correct answer: Technician name, date, amount recovered/added, and reason for service

EPA Section 608 requires owners of appliances with ≥50 lbs of refrigerant to keep records including dates, service performed, technician info, and amounts of refrigerant added or recovered.

Question 20: Which type of refrigerant is classified as 'A2L' (mildly flammable) under ASHRAE 34?

R-22
R-410A
R-32 (Correct answer)
R-134a

Correct answer: R-32

R-32 is classified as A2L — low toxicity (A) and mildly flammable (2L). A2L refrigerants have a low burning velocity and require ignition energy, but still require additional safety precautions compared to A1 refrigerants.

Question 21: What is the purpose of a Schrader valve core removal tool in refrigerant service?

To remove refrigerant cores to increase flow for faster recovery or charging (Correct answer)
To check refrigerant pressure
To remove moisture from the system
To test for refrigerant leaks

Correct answer: To remove refrigerant cores to increase flow for faster recovery or charging

A Schrader valve core removal tool allows removal of the valve core while maintaining a sealed connection, dramatically increasing refrigerant flow rate for faster recovery, evacuation, and charging operations.

Question 22: What does 'refrigerant recycle' mean in HVAC service?

Sending refrigerant to a certified reclaimer
Cleaning refrigerant on-site using recovery equipment with oil separation and filtration (Correct answer)
Recharging a system with previously used refrigerant
Converting one refrigerant type to another

Correct answer: Cleaning refrigerant on-site using recovery equipment with oil separation and filtration

Recycling means cleaning refrigerant on-site by removing oil and contaminants using single or multiple passes through equipment with oil separation and filtration. It does not restore refrigerant to virgin purity like reclaiming does.

Question 23: Which federal agency regulates the sale and use of refrigerants under Section 608?

OSHA
DOT
EPA (Correct answer)
NIOSH

Correct answer: EPA

The Environmental Protection Agency (EPA) administers and enforces Section 608 of the Clean Air Act, which governs refrigerant handling, recovery, and technician certification.

Question 24: What safety precaution should be taken when recovering refrigerant from a system suspected of having motor burnout?

Recover normally using standard equipment
Use a filter-drier on the inlet of the recovery machine to protect it from acids (Correct answer)
Vent the refrigerant since it's contaminated
Only recover vapor, never liquid

Correct answer: Use a filter-drier on the inlet of the recovery machine to protect it from acids

After a compressor burnout, refrigerant becomes highly acidic. A large-core filter-drier installed on the recovery machine's inlet protects the recovery machine from acid damage and oil contamination.

Question 25: What is the purpose of a 'lockout/tagout' (LOTO) procedure before recovering refrigerant?

To prevent refrigerant from escaping during recovery
To isolate energy sources to prevent accidental startup during service (Correct answer)
To lock the refrigerant cylinders to prevent theft
To tag the system as requiring refrigerant

Correct answer: To isolate energy sources to prevent accidental startup during service

LOTO procedures isolate all energy sources (electrical, pneumatic, hydraulic) to prevent accidental equipment startup while technicians are working on or near the equipment, protecting worker safety.

Question 26: When is it permissible to knowingly vent refrigerant under EPA Section 608?

Never — venting is always prohibited
For refrigerants with ODP of zero only
For small releases during connection/disconnection of hoses (Correct answer)
When the system is being permanently retired

Correct answer: For small releases during connection/disconnection of hoses

The EPA allows de minimis releases during normal connection and disconnection of service hoses, and for purging equipment of non-condensables that unavoidably contain refrigerant. Intentional venting is otherwise prohibited.

Question 27: Which type of cylinder is approved for refrigerant recovery — DOT or non-DOT?

Non-DOT cylinders only (gray color)
DOT-approved cylinders only (Correct answer)
Either type if properly labeled
Only manufacturer-supplied cylinders

Correct answer: DOT-approved cylinders only

Only DOT (Department of Transportation) approved cylinders may be used for refrigerant recovery and transport. They are designed to withstand pressure and are regulated for safety in transport.

Question 28: What effect does moisture contamination have on an R-22 refrigerant system?

Raises evaporator pressure, reducing efficiency
Reacts with refrigerant and oil to form hydrochloric and hydrofluoric acids (Correct answer)
Improves lubrication of the compressor
Has no significant effect

Correct answer: Reacts with refrigerant and oil to form hydrochloric and hydrofluoric acids

Moisture reacts with refrigerant and oil at high temperatures to form hydrochloric and hydrofluoric acids. These acids corrode system components, damage the compressor, and cause copper plating.

Question 29: What does a refrigerant identifier do before recovery?

Measures the amount of refrigerant in the system
Analyzes the refrigerant to identify type and detect contamination or mixes (Correct answer)
Checks system pressure against manufacturer specs
Verifies technician certification

Correct answer: Analyzes the refrigerant to identify type and detect contamination or mixes

A refrigerant identifier uses infrared or other sensing technology to identify the refrigerant type and detect contamination (air, wrong refrigerant mix, or non-condensables) before recovery to prevent cylinder cross-contamination.

Question 30: What is the required action if a leak is discovered on a system with 50+ lbs of refrigerant that exceeds the EPA leak rate threshold?

Immediately recover all refrigerant
Repair the leak within 30 days and verify repair (Correct answer)
File a report with the EPA within 24 hours
Add more refrigerant and monitor the system

Correct answer: Repair the leak within 30 days and verify repair

For systems with ≥50 lbs of refrigerant that exceed the EPA's leak rate threshold (30% of charge per year for commercial equipment), the leak must be repaired within 30 days, with a verified repair or retrofit/retirement plan.

Question 31: What is the boiling point of R-410A at atmospheric pressure?

-51.4°F (-46.3°C) (Correct answer)
-41.5°F (-40.8°C)
-12.0°F (-24.4°C)
2.5°F (-16.4°C)

Correct answer: -51.4°F (-46.3°C)

R-410A has a boiling point of approximately -51.4°F (-46.3°C) at atmospheric pressure (14.7 psia). This very low boiling point means it vaporizes rapidly if released, and systems operate at significantly higher pressures than R-22.

Question 32: What is the significance of ARI-700 purity standards for refrigerants?

It specifies the minimum recovery efficiency of recovery machines
It defines the purity specifications that reclaimed refrigerant must meet before resale (Correct answer)
It sets the maximum GWP for new refrigerants
It establishes cylinder pressure ratings

Correct answer: It defines the purity specifications that reclaimed refrigerant must meet before resale

ARI Standard 700 (now AHRI 700) establishes the minimum purity specifications for reclaimed refrigerants sold as new. Reclaimed refrigerant meeting ARI-700 is considered equivalent to virgin refrigerant.

Question 33: What personal protective equipment (PPE) is most critical when handling liquid refrigerant?

Steel-toed boots and hard hat
Safety glasses/goggles and insulated gloves (Correct answer)
Hearing protection and dust mask
Full face shield and chemical suit only

Correct answer: Safety glasses/goggles and insulated gloves

Safety glasses or goggles and insulated gloves are essential when handling liquid refrigerant. Liquid refrigerant can cause frostbite on skin contact and severe eye damage if splashed, due to its extremely low temperature.

Question 34: Which recovery technique is used when the system compressor is functional?

Passive recovery using system pressure only
System-dependent (active) recovery using the system's own compressor (Correct answer)
Push-pull recovery with external machine
Mega-recovery with liquid-only extraction

Correct answer: System-dependent (active) recovery using the system's own compressor

System-dependent recovery uses the equipment's own compressor to pump refrigerant into a recovery cylinder. This method is only allowed for small appliances (≤5 lbs of CFC or HCFC) and requires a functioning compressor.

Question 35: What happens to R-410A if it is charged as a liquid into the low side of a system?

Nothing unusual — it's the standard charging method
It can cause compressor slugging and damage (Correct answer)
It improves system efficiency
It vaporizes instantly and enters normally

Correct answer: It can cause compressor slugging and damage

R-410A is a zeotropic blend (though nearly azeotropic) and must be charged as a liquid to maintain the correct refrigerant composition. However, liquid refrigerant entering the compressor suction causes hydraulic slugging and compressor damage.

Question 36: What is the primary environmental concern with HFC refrigerants like R-410A, despite having zero ODP?

They deplete the ozone layer slowly
They are highly toxic in enclosed spaces
They are potent greenhouse gases with high Global Warming Potential (GWP) (Correct answer)
They react with groundwater

Correct answer: They are potent greenhouse gases with high Global Warming Potential (GWP)

While HFCs have zero ODP, they are powerful greenhouse gases. R-410A has a GWP of 2,088 — meaning it traps 2,088 times more heat than CO2. This is why the AIM Act is phasing down HFCs.

HVAC Refrigerant Recovery and Handling

What EPA regulation requires technicians to recover refrigerants before servicing equipment?

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