Future-Proof Your Building: An Inside Look at Low-GWP Refrigerant Replacements

On October 29, 2025, SVL welcomed Sharon Haeg of Daikin Applied for a packed Coffee Break Webinar on how to navigate low-GWP refrigerant retrofits and replacements. In just under an hour, Sharon explained the why, what, and how behind the transition, then walked through real-world “speed bumps” engineers, owners, and contractors are hitting—and practical paths around them.

Why this transition—and why now?

Sharon began by framing the environmental math. Refrigerants impact climate both directly (leakage to atmosphere) and indirectly (energy required to run equipment). The right lens is Life-Cycle Climate Performance (LCCP), not GWP alone. Using that lens, today’s A2L alternatives R32 and R454B cut total impact thanks to both lower GWP and higher efficiency. She also highlighted the AIM Act phase-down (a Kigali implementation), reminding everyone of the EPA’s key equation: CO₂e = GWP × mass—how the agency manages production allowances.

What’s changing in equipment?

The EPA’s technology-transition rules split gear into products (factory-charged) and systems (site-assembled/charged). Sharon reviewed the big dates already affecting selections, installation, and sell-through, plus special notes for VRF/VRV and data centers. Bottom line: confirm the rule set that applies to your scope and timelines before you plan procurement.

R32 vs. R454B: performance, cost, and supply

Both refrigerants are part of the HVAC industry’s transition toward lower-GWP alternatives that reduce environmental impact without sacrificing performance. Sharon notes that both are “here for the long haul,” with broad manufacturer adoption and comparable CO₂e when total system charge is considered. However, several attributes make R-32 stand out—especially in systems designed for long-term efficiency, ease of service, and sustainability.

1. Pure, Non-Proprietary Composition

Unlike R-454B, which is a blend of R-32 (68.9%) and R-1234yf (31.1%), R-32 is a pure, single-component refrigerant.

• No composition shift or glide: Its single-component nature ensures consistent performance and easier servicing since no fractionation occurs during leakage or charging.
• Non-proprietary: R-32 is openly available across manufacturers and not tied to any proprietary formulation or licensing restriction—supporting global adoption and lower long-term cost.

2. Easier to Work With

Because R-32 is pure, it can be charged in both liquid and gas phases, offering technicians greater flexibility. By contrast, blended refrigerants like R-454B must be charged in liquid form to maintain blend integrity.

This makes R-32:

• Easier to handle in the field
• Simpler to top off or reuse
• More predictable during recycling or recovery

3. Efficiency and Cost Advantages

Modeling and third-party studies—along with Daikin’s own field data—show that R-32 systems can be up to 12% more efficient than R-410A. Additional benefits include:

• Lower refrigerant cost per pound
• Smaller charge requirements, reducing total system refrigerant mass
• Reduced total CO₂e emissions thanks to high energy efficiency

4. Proven Global Adoption

R-32 has been used internationally since 2016, with more than 160 million units installed worldwide. Its proven track record ensures confidence in supply stability, technician training, and long-term support.

5. Environmental and Safety Profile

• Global Warming Potential (GWP): 675 — roughly one-third that of R-410A
• Safety Classification: A2L (lower flammability), same as R-454B
• Lower lifecycle climate impact (LCCP) due to higher system efficiency

Key Takeaway

While both R-32 and R-454B will play a role in decarbonizing HVAC, R-32 offers a simpler, proven, and globally accepted path forward. It’s pure composition, non-proprietary availability, and proven real-world efficiency make it a smart choice for engineers, contractors, and building owners focused on performance and sustainability.

For more insights and verified data points, visit R32Reasons.com — a Daikin resource with “32 reasons” why R-32 is helping shape the future of HVAC refrigerants.

Can I service or must I replace?

Not every project triggers a full refrigerant change. Sharon clarified EPA definitions separating “service/maintenance” from “new system” work. If you increase capacity or replace both evaporator and condensing unit, you’ve likely crossed into new-system territory and GWP < 700 applies. If not, many components labeled “for service only” can keep legacy systems running safely to end-of-life.

The safety standards that govern A2Ls

Sharon emphasized that retrofits to A2Ls are prohibited when the equipment wasn’t designed and listed for them. The governing product-safety standard (UL 60335-2-40) requires A2L-specific construction, leak testing, ignition-source controls, and marked application limits. Translation: use equipment that’s designed for A2Ls—don’t field-convert legacy A1 machines.

ASHRAE 15: where projects get stuck—and what to do

Two frequent “speed bumps”:

1. EDVC (Effective Dispersal Volume Charge). If releasable charge > EDVC, consider measures like connecting spaces (transfer grilles/door undercuts), leveraging ducted distribution to enlarge volume, mechanical exhaust for a leak event, safety shutoff valves (≤5-ton indoor units), or rezoning/smaller units to reduce charge. When those aren’t workable, hydronic conversions can remove A2Ls from the occupied zone.
2. Mitigation actions on leak detection. ASHRAE 15 may require opening zone dampers, activating exhaust, and de-energizing potential ignition sources—controls work that can be significant in existing buildings. If these measures are impractical, the viable path is again to keep A1s (when allowed under “service”) or move to hydronics.

She also covered refrigerant piping: A2L piping that penetrates two or more floor/ceiling assemblies typically requires a fire-rated, ventilated shaft. Alternatives may be possible via ASHRAE 15’s compliance options, but you must confirm with your AHJ and the governing mechanical code version.

Low-probability systems & machinery rooms

For chillers and other low-probability systems, watch machinery-room ventilation triggered by A2L concentrations (trouble vs. emergency thresholds). If ventilation and make-up air are tough to deliver, options include smaller modules, lower-pressure refrigerants, A1 chillers, air-cooled equipment outdoors, modular chiller plants, or, in some cases, Class I, Div 2 electrical design to reduce ventilation rates.

Practical O&M considerations

Plan for refrigerant availability, serviceability (single-component vs. blends), refrigerant cost exposure (initial charge and service), and efficiency impacts on utility spend. These factors often tip the scales between two otherwise code-compliant options.

Rapid-fire Q&A

• “Will R32 outlast 454B?” Sharon doesn’t expect either to disappear; adoption and CO₂e parity suggest both will remain.
• “Is a roof a floor/ceiling assembly?” Definitions live in the standard, and local AHJ has the final say—coordinate early.
• “Do we have to de-energize equipment that could spark?” ASHRAE 15 requires mitigation; A2L-listed equipment addresses ignition internally, but broader building controls may still be needed—work with your AHJ and SVL.

Don’t Miss the Next SVL Coffee Break

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