Technical Comparison

R290 vs CO₂ vs HFC: the refrigerant decision that ages best

The gas inside your next system decides its running cost, its service bills and whether it becomes a stranded asset. Here's the three-way comparison, honestly.

Why the refrigerant is a financial decision

Refrigerant choice reads like an engineering detail. It isn't. It sets three numbers your accountant will live with for fifteen years: the energy bill, the service bill, and the regulatory risk on the asset itself. Commercial systems leak — 8–15% of charge a year is typical — so you keep buying the gas you chose, at whatever it costs by then.

Three families, fairly compared

HFCs (R410A, R404A, R134a, R32)R290 (propane)CO₂ (R744)
GWP675 – 3,922. A kilo of leaked R404A ≈ nearly 4 tonnes of CO₂.31
Service gas priceHigh and rising — R404A ≈ ₱1,400/kg today, with the phasedown tightening supply.Low — an abundant industrial gas.≈ ₱50/kg. The cheapest refrigerant there is.
Best atGeneral HVAC where it already dominates.Heat pumps & hot water to ~75 °C — top efficiency in tropical heat.Refrigeration & freezing to −40 °C, plus high-temp heat to ~130 °C; rejects 65–75 °C water free.
Safety classMostly A1 non-flammable (R32 is A2L).A3 — flammable; engineered with small sealed charges (<1 kg) outdoors, to IEC 60335-2-40 / EN 378.Non-flammable, non-toxic; runs at high pressure — needs competent design.
Regulatory futurePhasedown in law (DAO 2021-31, Kigali schedule). The R22 precedent: service prices rose 5–10× as supply tightened.No phasedown clock.No phasedown clock.
PFAS / forever-chemical riskYes — common HFC/HFO breakdown products are PFAS that accumulate permanently. Full story.None. Breaks down to CO₂ and water.None.
Upfront cost & familiarityWins. Cheapest kit, every installer knows it, parts everywhere.Moderate; needs trained installers.Highest — pressure-rated components and specialist design.

Where HFCs honestly win: upfront price and universal familiarity. If you're certain the system will be replaced within a few years anyway, the cheap R410A unit can still be the rational buy. The trap is the fifteen-year asset bought today on a gas whose most expensive service years arrive mid-life.

The running-cost story in one cold store

This is where the families separate in pesos, not principles. An older R404A cold-store plant typically loses money three ways at once: refrigerant top-ups at ₱1,400/kg, electric defrost heaters fighting the freezer five times a day, and efficiency quietly degraded by non-condensable gases. At a typical mid-size facility that adds to around ₱4.1 million a year — before anyone looks at the tariff. A CO₂ plant with passive defrost removes all three, with paybacks under two years, and rejects 65–75 °C water free for washdown. The full breakdown is here.

What Karnot builds — and why

Karnot Energy Solutions Inc., based in Mapandan, Pangasinan, builds on natural refrigerants only: iHEAT R290 heat pumps for hot water and process heat, and iCOOL CO₂ systems for refrigeration and high-temperature duties, serving the Philippines, the UK, the US and Canada. Not for sentiment — because GWP 1–3, cheap service gas and no phasedown clock is simply the better fifteen-year deal. The technical data lives in our refrigerant properties tool.

Questions we get asked

What's the GWP difference, in plain terms?

R290 scores 3, CO₂ scores 1. The HFCs they replace score 675 to 3,922 — a kilo of leaked R404A has the climate impact of nearly four tonnes of CO₂.

Is CO₂ really cheaper to run than R404A?

Over the plant's life, substantially: ₱50/kg vs ₱1,400/kg for the gas you'll keep replacing, plus the defrost and efficiency penalties a modern CO₂ plant removes — around ₱4.1 million a year at a typical mid-size facility.

Is R290 propane safe?

Yes, engineered properly: non-toxic, small sealed charges under 1 kg, outdoor units, IEC 60335-2-40 and EN 378 design. The full safety explainer is here.

Will HFCs be phased out here?

The phasedown is already law (DAO 2021-31, following the Kigali schedule). The R22 precedent saw service prices rise 5–10× as supply tightened.

Where do HFCs still win?

Upfront price and familiarity. Short-horizon systems can still rationally be HFC — we'll tell you when that's true for your case.

Specifying a system this year?

Send us the duty — temperatures, loads, site — and we'll give you the honest three-way numbers for your case, including when the answer isn't ours.

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