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Quick answer
Choose ammonia (NH3) for general cold storage above 1,500 MT or large industrial freezers, and Freon, increasingly R32, below 1,500 MT and for commercial, retail and pharma rooms. Above 100 TR, ammonia is 10–15% more energy-efficient, but below 30 TR Freon is clearly better on total cost of ownership. Ammonia also needs a PESO licence and full safety systems.
Key takeaways
- R32 has a GWP of 675 against 2,088 for R410A and 1,430 for R134a, while R22 is banned for new installations.
- Ammonia plants need a PESO licence for storage above 50 kg, continuous gas detection and a 15-metre exclusion zone from public areas.
- Ammonia/CO2 cascade is becoming standard for −40°C industrial blast freezers above 100 TR, costing 30–45% more than pure ammonia with cost recovery in 4–6 years.
- HyperCold's selection rule is R32 with Daikin scroll under 30 TR, R32 or R449A for 30–80 TR, and ammonia screw with N+1 above 500 TR bulk storage.
- R22 systems cannot be retrofitted to R32, so retrofits to R449A or R407F are more common.
Quick Verdict
- Above 1,500 MT general cold storage or any large industrial freezer → ammonia (NH3)
- Below 1,500 MT, or any commercial/retail/pharma → Freon (R32 increasingly preferred over R410A and R134a due to lower GWP)
- Hybrid (ammonia-CO2 cascade) is becoming standard for −40°C industrial blast freezers above 100 TR
For most HyperCold projects (commercial and modular), R32 with Daikin equipment is the right pick.
Efficiency
At industrial scale (>100 TR), ammonia is 10–15% more energy-efficient than Freon — translates to lakhs of rupees per year on a large cold storage.
Below 100 TR the efficiency gap closes, and Freon's lower capital cost wins. Below 30 TR, Freon is dominantly better on total cost of ownership.
Benchmark kWh/MT-day numbers are in our electricity consumption guide.
Safety & Regulation
Ammonia is toxic, flammable (class B2L), and gives off a strong odour. Requirements:
- PESO licence for storage above 50 kg
- Trained operator certification
- Emergency safety shower and eye wash
- Continuous gas detection with alarm
- 15-metre exclusion zone from public areas
- Pollution category often Orange (vs Green for Freon)
Freon (R32, R410A, R449A) is non-toxic. R32 is mildly flammable (Class A2L) but acceptable for commercial use; R410A and R134a are non-flammable (Class A1).
Refrigerant Phase-Out Timeline
Under the Montreal Protocol + Kigali Amendment, India is phasing down high-GWP refrigerants:
| Refrigerant | GWP | Status |
|---|---|---|
| R22 (HCFC) | 1,810 | Banned for new installations |
| R134a | 1,430 | Phase-down 2024–2032 |
| R410A | 2,088 | Phase-down 2024–2032 |
| R32 | 675 | Preferred for now |
| R449A | 1,397 | Common for low-temp commercial |
| R454B | 466 | Emerging next-gen |
| Ammonia (NH3) | 0 | No restriction |
| CO2 (R744) | 1 | Emerging |
Spec refrigerant for a 15-year lifecycle, not for day one. R32 and R454B are safe bets through 2032+.
Industrial Hybrid — Ammonia/CO2 Cascade
For −40°C industrial blast freezers (export meat, seafood, large IQF), the modern standard is:
- Ammonia high-stage (chills CO2 to −40°C)
- CO2 low-stage (delivers cooling to evaporators)
Benefits: ammonia stays out of occupied zones, CO2 has zero toxicity, overall efficiency beats single-stage Freon at this temperature.
Capex 30–45% higher than pure ammonia, but operating cost recovery in 4–6 years for plants above 100 TR. Read our blast freezer vs cold storage comparison.
How HyperCold Recommends
- Walk-in and modular under 30 TR → R32 with Daikin scroll
- Commercial cold rooms 30–80 TR → R32 or R449A with screw or scroll
- Industrial cold rooms 80–500 TR → R449A scroll/screw, or ammonia for large bulk
- Above 500 TR bulk cold storage → ammonia screw with N+1
- Large export blast → ammonia/CO2 cascade
FAQ
Frequently asked questions
Is ammonia legal in India?
Yes — with PESO licence, trained operator, and full safety system. Most large bulk cold storages in India use ammonia.
Is R32 better than R410A?
Yes for new installations — R32 has lower GWP (675 vs 2,088), is mildly more efficient, and aligns with phase-down regulations.
Can I retrofit R22 to R32?
No — R32 requires different oil and components. Retrofit to R449A or R407F is more common, but new equipment is usually more economical at end-of-life.
Written by
HyperCold Engineering Team
Cold room and cold storage engineers at HyperCold™, a Daikin equipment partner founded in 2020 and headquartered in Sirsaganj, Firozabad (UP). We design, manufacture PUF panels for, install and maintain cold rooms across India.