170-Year-Old Heat Pump Technology Gets an Upgrade: Pascal Boosts Efficiency by 20% with Sponge Material

Heat pump technology has been around for 170 years, yet its core principles have barely changed. Startup Pascal is trying to rewrite that with a sponge-like material, claiming a 20% efficiency gain.

Starting from a 170-year-old technology

The basic principles of heat pumps and refrigeration date back to the mid-19th century, moving heat by compressing and expanding refrigerants. For over a century, this architecture has powered air conditioners, refrigerators, and heating systems, but efficiency gains have always been incremental.

Pascal's angle isn't the compressor or the piping—it's how the refrigerant itself works. According to the original report, the company uses a "sponge-like material" to redesign the heat pump and cooling cycle, promising efficiency gains of up to 20%.

The vapor compression cycle is the core of heat pump and refrigeration technology, with its thermodynamic basis in the reverse Carnot cycle. The system consists of four main components: compressor, condenser, expansion valve, and evaporator. The compressor compresses low-pressure gaseous refrigerant into high-temperature, high-pressure gas; the condenser releases heat to liquefy the refrigerant; the expansion valve reduces pressure and temperature; and the evaporator absorbs heat to vaporize it—cycling to move heat. The key efficiency metric is the coefficient of performance (COP), the ratio of heat output to electrical work input, typically 3–4 for residential heat pumps. Theoretically, reverse Carnot cycle efficiency depends only on source and sink temperatures, but real cycles are affected by refrigerant properties, component losses, and operating conditions. It's precisely this century of architectural stability that makes any efficiency gain beyond incremental optimization so noteworthy.

How the sponge material works

In public information, Pascal hasn't disclosed the material's specific chemical composition, but the "sponge-like" description points to porous structured materials—typically with enormous surface area that can move heat or working fluids through adsorption and desorption processes.

Compared with conventional vapor compression cycles, this approach may reduce energy losses in the compression stage, improving efficiency at the system level. If the 20% gain can be reproduced under real-world conditions, it would be significant for high-energy-consumption scenarios like heating and cooling.

That said, the figure currently comes from the company's own claims, with no third-party testing or peer-reviewed data yet available.

Porous materials are not a new concept in thermal management. Such materials (e.g., activated carbon, zeolites, metal-organic frameworks (MOFs), silica gel) have extremely high surface areas and can move heat through adsorption-desorption cycles: releasing heat during adsorption and absorbing heat during desorption, thereby creating a heat pump cycle without a traditional compressor. The advantage of adsorption heat pumps is that the driving heat source can be low-grade thermal energy (such as industrial waste heat or solar energy), with few moving parts and low noise. But challenges are equally clear: cycle stability of adsorbent materials, heat and mass transfer efficiency, and adsorption capacity per unit mass all directly affect system power density and lifespan. Pascal's "sponge-like material" likely falls into this category, but whether it's physisorption or chemisorption and how it integrates with the system have not been disclosed publicly.

The reality behind the efficiency number

The heat pump industry is no stranger to efficiency improvements, but there's often a gap between lab data and mass-production performance. Whether the 20% efficiency gain covers all operating conditions, whether material lifespan is sufficient, and whether costs can compete with existing systems are all key variables determining whether this technology can be deployed.

From the report, Pascal's positioning is innovation at the refrigerant and system level, rather than simply replacing a component. If this approach holds up, it could affect not only residential air conditioning but also commercial refrigeration and industrial thermal management.

Full-condition performance is a key dimension for evaluating heat pump efficiency. A heat pump's COP is not constant but varies significantly with outdoor temperature, supply water temperature, load ratio, and other operating parameters. For example, an air-source heat pump's COP may drop sharply from 3.5 at rated 7°C conditions to below 2.0 at -10°C in cold winter. Therefore, claiming a "20% efficiency improvement" must specify the test baseline: whether measured at rated conditions, part load, or annual comprehensive performance coefficients (such as SEER, SCOP). Additionally, material lifespan involves the degradation rate of adsorbents after thousands of cycles, and cost must be compared against the unit cooling capacity cost of conventional compressor systems. These variables together determine whether the new technology can move from the lab to large-scale mass production.

Worth watching but needs verification

Based on available information, Pascal's approach offers a direction worth watching: breaking through heat pump efficiency bottlenecks through material innovation rather than mechanical optimization. But "20% more efficient" is currently still a company claim, lacking independent verification. While keeping an eye on this technology, we should wait for more test data and productization progress.

The 170-year history of heat pumps shows that true efficiency leaps often require fundamental-level changes. Whether Pascal can deliver on its promise will hinge on its ability to engineer materials science.