HFO Refrigerants — How to Choose R-449A, R-452A, R-454B, R-513A for HFC/HCFC Retrofit

Thailand is phasing out R-22 by 2030 under the Montreal Protocol, and R-404A / R-410A / R-134a (GWP 1,500–4,000) face increasing pressure from the Kigali Amendment (Thailand ratified 2019), which mandates 85% reduction of HFC production by 2045.

Compressor OEMs (Daikin, Trane, Carrier, York) now recommend HFO blends (Hydrofluoroolefin) — next-generation refrigerants with GWP < 700 and ODP = 0. Some are drop-in retrofits that work without replacing the compressor.

This article summarises the four leading HFO grades used for retrofit in Thailand and how to choose by existing system.

What is HFO — How is it different from HFC?

HFC (Hydrofluorocarbon) = saturated refrigerant (single bonds) — ODP=0 but high GWP (long atmospheric lifetime).

HFO (Hydrofluoroolefin) = HFC + double bond (C=C) → decomposes in the atmosphere within 11 days → very low GWP (<10 or blended ~100–1,400).

HFO blends (e.g. R-449A) mix HFO + HFC to match the thermodynamic behaviour of the original refrigerant.

graph LR
    A[Existing system] --> B{Choose HFO replacement}
    B -->|R-22 chiller| C[R-407C or R-449A]
    B -->|R-404A cold storage| D[R-449A / Opteon XP40]
    B -->|R-134a chiller| E[R-513A / Solstice]
    B -->|R-410A split AC| F[R-454B]
    B -->|Transport refrigeration| G[R-452A / Opteon XP44]
    C --> H[GWP 1,397]
    D --> H
    E --> I[GWP 573]
    F --> J[GWP 466 A2L]
    G --> K[GWP 2,140]

1. R-449A (Opteon XP40) — Replaces R-404A

Specifications

Property	Value
Family	HFO blend (R-32/R-125/R-1234yf/R-134a)
ASHRAE Safety	A1 (non-flammable)
GWP (AR5)	1,397
ODP	0
Boiling point	-45.9°C
Temperature glide	~4 K
Compressor oil	POE (existing R-404A oil compatible)

Applications

• Supermarket refrigeration display cases
• Cold storage warehouses
• Walk-in freezers / coolers
• Cold-chain logistics (7-Eleven, Big C, Tesco, Lotus)

Retrofit from R-404A

• 65% GWP reduction (3,922 → 1,397)
• Compatible with existing POE oil — no flush needed
• Cooling capacity 95–98% of R-404A
• 8–12% better COP than R-404A (per field data — energy savings)
• Existing TXV/EEV expansion valves work

Cautions

• 5.1°C glide → flooded evaporators require redesign
• Replace gauge manifold (R-404A gauge reads incorrect pressures)

2. R-454B — Replaces R-410A in New Split AC + Chillers

Specifications

Property	Value
Family	HFO blend (R-32/R-1234yf 68.9/31.1%)
ASHRAE Safety	A2L (mildly flammable)
GWP (AR5)	466
ODP	0
Boiling point	-50.9°C
Glide	1.5°C
Compressor oil	POE

Applications

• New split AC (Daikin, Carrier, Trane from 2023+)
• Heat pumps (residential + commercial)
• VRF systems designed for R-454B
• Mid-size chillers

Retrofit considerations from R-410A

• 78% GWP reduction (2,088 → 466)
• A2L (mildly flammable) requires:
  • Adequate room ventilation per EN 378-1 / ASHRAE 15
  • Refrigerant Concentration Limit (RCL) per room volume
  • No ignition sources within 1m
• Compressor must be A2L-rated — most legacy R-410A compressors do NOT work with R-454B
• Do NOT reuse R-410A vacuum pumps — pressure specs differ

Recommendation

• New equipment → R-454B (compliance + future-proof)
• Existing R-410A → service until end of life, then replace with R-32 or R-454B equipment

3. R-513A (Solstice N13) — Replaces R-134a in Chillers

Specifications

Property	Value
Family	HFO blend (R-1234yf/R-134a 56/44%)
ASHRAE Safety	A1 (non-flammable)
GWP (AR5)	573
ODP	0
Boiling point	-29.2°C
Glide	<0.1°C (azeotrope-like)
Compressor oil	POE / PAG

Applications

• Large centrifugal chillers (data centre, hospital)
• Screw chillers
• Process cooling (plastics, food)

Retrofit from R-134a

• 60% GWP reduction (1,430 → 573)
• Near-zero glide → true drop-in retrofit
• Compatible with existing POE oil
• 99% of R-134a capacity
• Pressures match R-134a → no expansion valve change required

Advantage

• A1 classification (non-flammable) — unlike A2L R-454B, can be installed anywhere

4. R-452A (Opteon XP44) — Transport Refrigeration

Specifications

Property	Value
Family	HFO blend — R-32 (11%) / R-125 (59%) / R-1234yf (30%) zeotropic
ASHRAE Safety	A1
GWP (AR4 / AR5)	2,140 / 1,945
Boiling point	-47.0°C
Glide	3.8°C
Compressor oil	POE (Emkarate™ RL recommended)
Discharge temperature	Close to R-404A → reduces compressor stress

Applications

• Reefer containers
• Refrigerated trucks
• Cold-chain logistics (Kerry Cool, J&T Cold, DHL Cold)

Retrofit from R-404A

• 45% GWP reduction (3,922 → 2,140)
• Engineered specifically for transport at high ambient (40–55°C)
• Compressor runs cooler than on R-404A → extends compressor life

Comparison Summary

HFO	Replaces	GWP	Class	Glide	Oil	Best for
R-454B	R-410A	466	A2L	1.5°C	POE	New split AC + heat pumps
R-513A	R-134a	573	A1	<0.1°C	POE/PAG	Chillers (drop-in retrofit)
R-449A (XP40)	R-404A	1,397	A1	~4 K	POE	Cold storage, supermarket (+8-12% COP vs R-404A)
R-454C	R-410A	148	A2L	1.8°C	POE	Modern AC (lowest GWP)
R-452A (XP44)	R-404A	2,140	A1	3.8°C	POE	Transport refrigeration
R-1234yf	R-134a	4–7	A2L	0°C	PAG	Automotive AC (Euro 6+)

FAQ

Q: Can we keep servicing legacy R-22 / R-404A systems?

A: Yes, but it becomes progressively harder:

• R-22 production banned in Thailand from 2030 → prices will spike (recycled stock only)
• R-404A still available but import tax rising yearly under Kigali HFC quotas
• Compressor OEMs (Bitzer, Bristol, Copeland) have stopped producing R-22 compressors → spare parts scarce
• Plan a retrofit within 3–5 years

Q: Do we need a Hazardous Substances licence (วอ.)?

A: Yes — every refrigerant in Thailand is a hazardous substance under the Hazardous Substance Act B.E. 2535. Both importers and resellers need the วอ. licence (Type 3). Sahawatthanakit holds full licences — retail, bulk, nationwide delivery.

Q: Is A2L flammable refrigerant dangerous?

A: A2L = "mildly flammable" — much harder to ignite than natural gas (LFL ~6.8% v/v vs methane 5%) but you must comply with:

• EN 378-1 — charge limit per room volume
• ASHRAE 15 — ventilation requirements
• IEC 60335-2-40 — safety of AC + heat pumps
• Room must include gas detector + ventilation

Q: Why does AHRI 700 (2019) certification matter for TOR specs?

A: AHRI 700 sets the purity standard for refrigerants — limits on water, acid, non-condensable gas. Government TORs require COC + lab test report per AHRI 700 — Sahawatthanakit ships complete documentation with every lot.

Quote Request

Sahawatthanakit carries 16 refrigerant grades — full HCFC + HFC + HFO + Specialty — AHRI 700 (2019) certified + complete วอ. hazardous substances licensing.

• Phone: +66-2-096-2118
• LINE: @406rrgvm
• Email: info@sahawatthanakit1988.com
• Request quote: /en/quote?service=refrigerant