Advanced Training HVACR
2026 transition · ASHRAE 34 · UL 60335-2-40

A2L Refrigerant Training

A2L refrigerants — R-32, R-454B, R-454C, R-1234yf — are replacing high-GWP A1s like R-410A across new HVAC equipment under the EPA AIM Act phase-down. This course covers safety classification per ASHRAE 34, leak-detection methods, charge-limit calculations per UL 60335-2-40, and field-installation procedures specific to A2L systems. ~8 hours. Free with the Apprentice tier.

Why A2L matters now

The EPA AIM Act phase-down requires an 85% reduction in HFC consumption by 2036. The intermediate milestone — January 1, 2025 — caps GWP for new residential AC and heat-pump equipment at 700, which effectively mandates A2L. Every new install you touch from 2026 onward is more likely to be A2L than A1.

~466

R-454B's global warming potential vs ~2,088 for R-410A. About 78% lower.

≤700

Maximum allowed GWP for new residential AC + heat pump equipment manufactured after Jan 1, 2025.

85%

HFC consumption phase-down target by 2036 under the AIM Act of 2020.

What you'll learn

  • Safety classification — ASHRAE Standard 34: A1 vs A2L vs A3, lower-flammability-limit math, burning velocity threshold.
  • Charge limit calculations — UL 60335-2-40 for residential / light commercial; max charge per occupied volume.
  • Leak detection requirements — when permanent leak sensors at the indoor unit are mandatory; how mitigation (fan-on, alarm) sequences work.
  • Brazing + service practices — no open flame on charged systems; recover-then-braze workflow; ignition-source mitigation in mechanical rooms.
  • Equipment compatibility — which existing R-410A line sets, condensers, and air handlers can/can't be reused with R-454B retrofits.
  • Field-installation differences — pressure ratings, oil compatibility, vacuum requirements, leak-test pressures.

Common A2L refrigerants in 2026

R-454B (Opteon XL41)

Carrier, Trane, and several other OEMs' choice for new residential and light commercial AC + heat pumps. GWP ~466.

R-32 (Difluoromethane)

Daikin, Mitsubishi, and most of Asia's choice. GWP ~675. Common in mini-splits.

R-454C (Opteon XL20)

Lower-charge applications. GWP ~148.

R-1234yf (Opteon YF / Solstice yf)

Auto AC standard since 2017. GWP <1.

Get current on A2L now

~8 hours of focused training puts you ahead of most field techs on the 2026 transition. Free with Apprentice tier.