Practice Test Geeks(A2L) A2L Low GWP Flammable Refrigerant Safety Certification Practice Test
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Properties and Classification Flashcards

6 cards from real A2L practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Properties and Classification flashcards as text

  1. What does the 'A2L' classification mean in the ASHRAE 34 safety classification system?

    Answer: Lower toxicity (A), lower flammability (2), with low burning velocity (L)

    In ASHRAE 34: 'A' means lower toxicity, '2' means lower flammability (can burn but requires higher ignition energy), and 'L' indicates low burning velocity — flames spread slowly.

  2. What is the Global Warming Potential (GWP) advantage of A2L refrigerants over R-410A?

    Answer: A2L alternatives typically have GWP 1/3 to 1/4 of R-410A's GWP of 2088

    R-410A has a GWP of 2088. Common A2L replacements like R-32 (GWP 675) and R-454B (GWP 466) offer 67-78% lower global warming impact per unit.

  3. How does the burning velocity of A2L refrigerants compare to common flammable gases like propane?

    Answer: A2L refrigerants burn at less than 10 cm/s — roughly 1/4 the speed of propane

    A2L refrigerants have a maximum burning velocity of 10 cm/s, compared to propane at approximately 40 cm/s. This slower flame spread is a key safety advantage.

  4. What is the minimum ignition energy (MIE) for most A2L refrigerants and why does it matter?

    Answer: Relatively high — typically 100-1000+ millijoules, much higher than common flammable gases

    A2L refrigerants require significantly more energy to ignite than common flammable gases. This high MIE means common ignition sources (static discharge, small sparks) are unlikely to cause ignition.

  5. Which common A2L refrigerant is a single-component (non-blended) refrigerant?

    Answer: R-32

    R-32 (difluoromethane) is a single-component refrigerant. R-454B is a blend of R-32 and R-1234yf. Single-component refrigerants are simpler to handle since they don't fractionate.

  6. At what approximate temperature range do most A2L refrigerants auto-ignite?

    Answer: 500-750°C

    Most A2L refrigerants have auto-ignition temperatures in the 500-750°C range. Normal HVAC system temperatures (below 150°C) are far below this threshold.