From a nation of just two million, a breakthrough in cooling is rewriting the playbook. The innovation emerging from Slovenia challenges a century of compressor design, replacing gas refrigerants with a solid-state, pressure-driven cycle. It’s a quiet but profound shift, aligning comfort with climate responsibility.
A radical new way to cool
At the University of Ljubljana, researchers built a system that sidesteps refrigerants entirely. Instead of evaporating gases, it harnesses elastocaloric materials that heat when squeezed and cool when released. This approach moves cooling from a chemical to a mechanical domain, cutting climate harm at its source.
The core material is nitinol, a nickel–titanium alloy famous for shape-memory behavior. Under stress it rearranges its crystal structure, releasing heat; when the stress drops, it absorbs heat, creating a repeatable cooling cycle. The result is a compact, modular system that replaces compressors with precisely tuned actuators.
Early prototypes hit about 15% efficiency compared with 20–30% for conventional units. That gap hides the technology’s youth: gas cycles have had a century of optimization, while elastocalorics are barely a decade into development. The trajectory points toward rapid gains as materials, mechanics, and controls improve.
How pressure replaces gas
In an elastocaloric device, specialized alloys sit within a heat-exchange assembly. A motor or piezo actuator applies pressure, raising the alloy’s temperature, which transfers heat to a sink. Releasing pressure cools the alloy, which then absorbs heat from the airflow you want to cool. Sequencing many tiny elements creates a smooth, continuous cycle.
Because there’s no evaporation, there are no hydrofluorocarbon (HFC) leaks or top-ups. The loop is a solid, recyclable structure that can be built to run quietly with fewer moving parts. It’s an elegant translation of physics into a practical household or industrial tool.
“As we move away from gases, we move away from leaks,” says one project engineer. “What’s good for the planet can also be good for performance.”
Key advantages include:
- Zero refrigerants, zero leakage
- Lower acoustic noise, fewer vibrations
- Recyclable core materials, simpler servicing
- Modular design, from appliances to datacenters
- Safer operating profile, no toxic fluids
Europe’s collaborative sprint to market
Slovenia’s effort sits inside E-CO-HEAT, a European consortium pushing lab results toward industry. Partners in Ireland, Germany, and Italy bring manufacturing, engineering, and testing expertise to harden designs for real-world conditions. Backing from EU programs like SUPERCOOL aligns the project with the European Green Deal and heating–cooling strategy.
A flagship prototype called SMACool is being prepared for validation and early market pilots. The aim is to prove reliability across climates and loads, then scale production for appliances, buildings, and specialized cooling markets.
Why this matters right now
Air conditioning already uses about 10% of global electricity, a share set to grow as temperatures and incomes rise. Current machines rely on HFCs, which can trap thousands of times more heat than CO₂. Each kilogram lost to the atmosphere is a long-lived climate liability baked into our comfort.
A gas-free pathway reframes the trade-offs. It shrinks lifecycle emissions from leaks, simplifies compliance as refrigerant rules tighten, and opens the door to all-electric, climate-first building design. Pair elastocalorics with efficient fans and renewable power, and cooling becomes a much lighter load on the grid.
Beyond the living room
Potential applications stretch from household units to cold-chain logistics. Datacenter thermal management, EV battery conditioning, supermarket refrigeration racks, and compact medical coolers all face the same challenge: move heat cleanly, quietly, and efficiently. Elastocaloric modules can be tuned for size, duty cycle, and integration with smart controls.
The materials science is also a launchpad for innovation. Advances in alloy formulations, surface treatments, and actuator design promise higher durability and COP. Add predictive software and machine learning, and systems can adapt in real time to weather and occupancy patterns.
Hurdles—and a realistic path
Three challenges loom: efficiency, durability under repeated cycling, and cost at scale. Today’s devices must close the gap with mature compressors, survive millions of cycles, and hit price points that convince cautious buyers. That journey requires tight engineering, robust supply chains, and strong after-sales support.
Yet the momentum is real. Policy tailwinds, corporate sustainability targets, and rising consumer awareness are aligning incentives like never before. If pilot deployments confirm lifetime performance, procurement can shift quickly in sectors that buy cooling by the megawatt.
Slovenia has shown how a small country can change a big industry. By swapping gas for geometry, and chemistry for mechanics, its researchers have opened a path to comfort with far less cost to the climate we all share.
