Climate protection from the cold: how Switzerland avoids emissions from old refrigerators

Replacing refrigerants and blowing agents since 1994

The ozone-depleting refrigerant CFC R-12 was replaced in stages, initially by the ozone-compatible HFC R-134a, which still had global warming potential, and later by the hydrocarbon R-600a, which is unproblematic in both respects. This was based on international agreements such as the Vienna Convention and the Montreal Protocol. The change in the blowing agents used for PU foaming was quicker and earlier. Here, the CFC R-11 was directly replaced by the ozone-friendly hydrocarbon cyclopentane, which has practically negligible global warming potential.

This streamlined transition in appliance production was also reflected in recycling, as the proportion of recycled compressors with VHC operation has been steadily increasing since 2003 (stage 1). In the case of VHC-foamed housings, this trend was already visible in 2000 (stage 2). Experts expected the trajectory for the proportion of climate-damaging VFC appliances to nosedive as a result. In fact, the opposite was the case: the downward trajectory is approaching the x-axis much slower than expected for both the VFC-filled compressors and the VFC-foamed PU insulation. In 2024, 21% of compressors and 17% of appliance insulation were still from older designs with components containing VFCs. Ammonia absorber devices (often minibars) have remained at a low level of almost 2% for many years.

A major impact on the climate

If these pollutants are not properly removed from the appliances, they are released into the atmosphere – with drastic consequences. A single kilogram of these substances has the climate impact of several tonnes of CO₂. To prevent this, Switzerland is already onto a second generation of recycling plants (replacing two outdated plants in 2022 and 2023). These plants ensure controlled recovery of refrigerants and propellants using state-of-the-art shredding technology and process air treatment before equally controlled thermal splitting in a high-temperature incineration plant. This results in CO₂, water, salts and acids – products that have a much lower or negligible impact on the climate.

And this effort is paying off: By rendering these substances harmless alone, around 160,000 tonnes of CO₂ equivalents were avoided last year. This greenhouse gas avoidance corresponds to around 85–90% of the annual overall climate benefit of the SENS take-back system (LCA Carbotech AG 2024).

State-of-the-art two-stage recovery processes

State-of-the-art recycling plants – such as those operated by the three companies Immark AG in Aarwangen, E. Flückiger AG in Rothrist and Oeko-Service Schweiz AG in Rheinfelden – operate in two stages. In the first, manual step, the refrigerant circuits or compressors are tapped using a tong or drilling head system and the refrigerants and oil are extracted.

Glass and the fully extracted copper-bearing compressors are also removed prior to mechanical processing

and recycled. Components containing pollutants such as capacitors or mercury switches are removed thermally. The appliance casings then go on to the fully automated shredding and propellant recovery stage.

This entirely gas-tight process produces ferrous and non-ferrous metals, as well as high-quality plastics, as recyclable fractions. The fully degassed polyurethane can be used as a recycled material to an extent, but it is usually still burned as a substitute fuel in cement plants. Blowing agents are adsorbed on cascaded activated carbon filters, regenerated using steam and condensed via a chiller. The liquefied mixture of blowing agents is pumped into gas cylinders to be disposed of in a special waste incinerator, just like the refrigerants.

Declining key figures with consistent efficiency

The amount of recovered refrigerant and propellant mixtures fluctuates from one year to the next due to the changing composition of appliances. VHC filling quantities and concentrations in PU are considerably lower than in VFC devices, so the trend is moving towards decreasing volumes of recovered gas with proven consistency in plant performance.

For 2024, the following key figures apply to the substances recovered from foamed compressor appliances before being thermally removed:

• VFC/VHC refrigerant mixture per compressor: 49 g (previous year: 68 g, −27%)
• Oil per compressor: 140 g (previous year: 148 g, −5%)
• VFC/VHC propellant mixture: 47 g/kg PU foam (previous year: 51 g/kg, −8%)

Improper equipment logistics: a health and safety issue

Before refrigerators, dehumidifiers and air conditioning systems enter the high-tech recycling process, another quality criterion comes into focus: the condition of the appliances delivered for recycling. They are not always perfect. For a significant proportion of appliances with defective refrigeration circuits, the cause of the damage (refrigerant leakage!) is careless handling in delivery of the appliance – at the construction site or collection point or at the disposal or logistics company that prepares the appliances for transport to the recycling plant. Devices are often randomly loaded into containers and pressed together, damaging cooling circuits and housings. This not only contradicts the standard requirements for proper, environmentally responsible equipment logistics; it is also dangerous. Loose parts can fall off or drop out during the unloading process and injure transport personnel, torn lines and housings can lead to deep cuts, while crushed, entangled appliances can trigger uncontrolled falling of other appliances. Careful collection and diligent, proper loading of equipment are tremendously important for both environmental protection and occupational safety. Here, SENS and its certified recycling partners appeal above all to the personal responsibility of all market participants.

Conclusion: effective levers for climate protection

Careful logistics around disused refrigerators and technologically advanced recycling remain indispensable levers on the path to decarbonisation. Even though the majority of end-of-life appliances are already environmentally friendly, there is still great potential for CO₂ avoidance in the thousands and thousands of conventional appliances. Switzerland’s sophisticated recycling system shows how technological precision and environmental responsibility can go hand in hand. It also shows the relevance of state-of-the-art recycling of disused refrigerators for environmental and climate protection – both now and for a long time to come.