What R290 is
R290 is high-purity propane, a hydrocarbon. It is not the same as LPG cylinder gas, which is a mixture with impurities and odorants and must never be used in a refrigeration system. R290 boils at about −42 °C at atmospheric pressure, which suits both chilled and frozen applications.
It has zero ozone depletion potential and a global warming potential in the low single digits on the standard 100-year scale. By comparison, R134a is 1,430 and R404A is 3,922 on the IPCC AR4 100-year scale used for Kigali reporting.
Why manufacturers use it
- Climate: very low GWP, so leaks have little direct warming effect and it is not targeted by HFC phase-downs.
- Efficiency: good heat-transfer properties; well-designed R290 systems often match or beat equivalent HFC systems.
- Small charge: a given cooling capacity needs a much smaller mass of refrigerant than HFC alternatives.
- Availability: propane is widely produced, and refrigerant-grade R290 is available in India.
Flammability and safety class
R290 is classed A3: low toxicity, high flammability. A leak that builds up a flammable concentration near an ignition source could ignite. That is why equipment using R290 is designed with small, sealed refrigerant circuits, sealed or spark-free electrical components near the refrigerant, and charge limits linked to the space where the unit is installed.
In normal use a properly built R290 cabinet is safe. The risk is concentrated during service, repair and disposal, when the circuit is opened.
Propane is heavier than air, so leaked gas tends to collect at floor level and in pits or basements. That is one reason installation instructions specify minimum room sizes and ventilation, and why units should not stand in small, sealed cupboards.
Charge limits in self-contained cabinets
The international appliance safety standard for commercial refrigerating appliances, IEC 60335-2-89, was revised in 2019. The revision raised the allowed charge of A3 refrigerants such as R290 in self-contained commercial units from 150 g to about 500 g per circuit, subject to further conditions in the standard. Larger cabinets therefore no longer need to split into many small circuits. National adoption and the exact conditions vary, so check what standard your equipment is certified to.
What changes for service technicians
| Task | R290 requirement |
|---|---|
| Training | Technician trained in hydrocarbon safety |
| Tools | Tools and recovery equipment rated for flammable refrigerants |
| Leak detection | Flammable-gas detector in the work area |
| Brazing | Circuit purged and refrigerant removed before any flame or heat |
| Ventilation | Good ventilation; no ignition sources near the work |
| Charging | Charged by weight to the exact nameplate amount |
| Labelling | Flammable refrigerant labels kept clear and visible |
What owners should do
- Use only service providers who confirm they are trained and equipped for hydrocarbon refrigerants.
- Do not let anyone 'top up' an R290 unit with a different refrigerant.
- Keep the area around the cabinet's compressor compartment free of stored LPG cylinders and open flames.
- Leave the manufacturer's flammable-refrigerant labels in place.
- At end of life, use a recycler who handles refrigerant recovery properly.
Frequently asked questions
- Is R290 safe in a restaurant kitchen?
- Properly designed and certified R290 equipment is widely used in commercial kitchens. Safety depends on design, charge limits, correct installation and trained service. Follow the manufacturer's installation instructions.
- Can my R134a unit be converted to R290?
- Not simply. Components, electrical parts and charge limits are designed for a specific refrigerant. Converting a unit not designed for flammable refrigerant creates real safety risks. Replacing it with a unit designed for R290 is the safe route.
- How do I know which refrigerant my cabinet uses?
- Check the rating plate, usually inside the cabinet or at the back near the compressor compartment. It lists the refrigerant type and charge in grams. Hydrocarbon units also carry a flammable-refrigerant warning symbol.
- Does R290 cool better than R134a?
- It has favourable properties and good systems are very efficient, but the overall result depends on the whole design. Compare measured energy use rather than the refrigerant name alone.
