Mixed Deck — All EPA 609 Topics Flashcards

Which refrigerant was primarily targeted for phase-out under the Montreal Protocol as implemented in US law?

Answer: R-12 (CFC-12)

R-12 (CFC-12) was the primary MVAC refrigerant phased out due to its high ozone depletion potential under the Montreal Protocol.

The high-pressure side of an MVAC system runs between which components?

Answer: Compressor outlet to evaporator inlet (through condenser)

The high-pressure side runs from the compressor outlet through the condenser and to the metering device inlet.

What device in an MVAC system controls the flow of refrigerant into the evaporator?

Answer: Thermal Expansion Valve (TXV) or Orifice Tube

A TXV or orifice tube meters liquid refrigerant into the evaporator, maintaining the correct pressure drop for proper evaporation.

A refrigerant identifier should be used before recovering refrigerant from an MVAC system primarily to:

Answer: Detect refrigerant contamination or incorrect refrigerant type that could damage recovery equipment

Contaminated or mixed refrigerants can damage recovery machines and cross-contaminate the recovery cylinder; identifying the refrigerant type first protects equipment and ensures proper handling.

What is the ozone depletion potential (ODP) of R-134a?

Answer: 0.0

R-134a has an ODP of zero, which is why it was approved as a replacement for the ozone-depleting R-12.

Frost or ice forming on the orifice tube or expansion valve in an MVAC system usually signals:

Answer: A restriction or moisture contamination causing a pressure/temperature drop

A restriction or moisture freeze at the metering device causes a dramatic pressure and temperature drop immediately downstream, leading to ice formation.

Recovery equipment for MVAC systems must be certified to which standard?

Answer: SAE J2788

MVAC refrigerant recovery/recycling equipment must meet SAE J2788 standards, which specify recovery and purity efficiency requirements.

After completing refrigerant charge on an MVAC system, system performance is most accurately verified by:

Answer: Measuring vent outlet temperature and comparing manifold pressures to specification charts

Measuring actual vent temperature (typically 35–45°F from center vents) and comparing gauge pressures to ambient-temperature-based specification charts confirms the system is performing within design parameters.

What does SNAP stand for in the context of EPA refrigerant regulations?

Answer: Significant New Alternatives Policy

SNAP (Significant New Alternatives Policy) is the EPA program that evaluates and approves substitute refrigerants to ensure they are safe alternatives to ozone-depleting substances.

Before opening any MVAC system for repairs, what must a technician do first?

Answer: Recover all refrigerant using approved equipment

EPA regulations require that all refrigerant must be recovered using approved recovery equipment before any MVAC system component is opened.

To purchase refrigerant in containers larger than 2 pounds, a technician must show proof of:

Answer: EPA Section 609 technician certification

Refrigerant sellers are required to verify that purchasers of containers over 2 lbs hold valid EPA Section 609 certification.

An EPA inspector arrives at a shop and requests refrigerant purchase records. The shop must:

Answer: Provide records going back at least 3 years

Shops must maintain and provide EPA inspectors access to at least 3 years of refrigerant purchase and service records upon request.

How long is an EPA Section 609 certification valid?

Answer: Indefinitely — it does not expire

EPA Section 609 certification does not expire and is valid indefinitely once earned.

What is the boiling point of R-134a at atmospheric pressure?

Answer: -26.3°F (-32.4°C)

R-134a boils at approximately -26.3°F (-32.4°C) at atmospheric pressure, which allows it to absorb heat efficiently in the evaporator.

The maximum fill level for refrigerant recovery cylinders is:

Answer: 80% of water capacity by weight

Recovery cylinders must never be filled beyond 80% of their water capacity by weight to allow for refrigerant expansion.

Which type of leak detector offers the highest sensitivity for finding very small refrigerant leaks?

Answer: Heated diode (infrared) or heated element electronic detector

Heated diode and infrared electronic detectors are highly sensitive to refrigerant molecules and can detect leaks as small as 0.1 oz/year, far below what other methods can detect.

What is a typical high-side pressure reading for a properly charged R-134a MVAC system?

Answer: 150–250 psi

The high side of an R-134a system typically operates between 150–250 psi depending on ambient temperature and load.

What is the primary function of the compressor in an MVAC system?

Answer: To pressurize refrigerant vapor and circulate it through the system

The compressor pumps and pressurizes refrigerant vapor, raising its temperature before it enters the condenser to release heat.

An MVAC system that blows warm air while the compressor is running could indicate:

Answer: A refrigerant leak causing low charge

A refrigerant leak reduces system charge, lowering refrigerant flow and heat absorption, so the evaporator cannot cool adequately even though the compressor runs.

What is the ASHRAE safety classification of R-134a?

Answer: A1 (non-toxic, non-flammable)

R-134a is classified A1 by ASHRAE, indicating it has low toxicity and is non-flammable under normal conditions.