Solid refrigerant system attracts $8m investment

USA: A startup developing high-efficiency heat pumps, air conditioners and refrigerators based on solid refrigerant technology has raised $8m from investors.

Launched out of Harvard University, Pascal is using a novel class of solid barocaloric refrigerants based on metal-halide perovskites, operating at lower pressures than previously possible.

Pascal maintains that its heat pump will deliver higher efficiencies at lower costs while eliminating refrigerant emissions. 

The funding led by Engine Ventures, with Khosla Ventures and previous investor Blindspot Ventures participating, will be used to commerialise Pascal’s system and expand its Boston-based team of mechanical engineers, chemists and material scientists. 

Barocaloric materials work similarly to traditional gas-liquid cooling systems, using pressure changes to go through heat cycles, but in this case, the pressure drives a solid-to-solid phase change. That means the material remains a solid, but the internal molecular structure changes. The key structural aspect of these barocaloric solid materials is that they contain long, flexible molecular chains that are typically floppy and disordered. But under pressure, the chains become more ordered and rigid — a change that releases heat.

Historically, solid refrigerants have required massive pressure to induce the large thermal changes required for transporting heat from one location to another. As a result, solid refrigerant systems typically require specialised pressure vessels, pumps and compressors, making them prohibitively expensive. 

Pascal’s novel class of solid refrigerants operate at lower pressures than previously possible and, according to the development team, can be used across a range of HVAC applications, including heat pumps, air conditioners, refrigerators and freezers. 

The company believes its systems can be manufactured within the existing industrial ecosystem, using off-the-shelf parts from the conventional HVAC component supply chain. 

“We’ve not only discovered a new class of solid materials ideal for refrigeration, we’ve also identified a new way to use pressure to induce phase transitions in these solid materials. This allows us to drive heating and cooling cycles with significantly reduced energy input,” said Jinyoung Seo, co-founder and CTO of Pascal. “Over the past two years, we’ve driven down the operating pressures of our solid refrigerants by several orders of magnitude, unlocking cost-effective systems that can work with existing HVAC compressors and components.” 

Pascal launched from the Mason Group at Harvard University, a research group led by Jarad Mason in the Department of Chemistry and Chemical Biology that applies the tools of coordination chemistry, materials science and nanotechnology to design materials that address science challenges in energy and medicine. Dr Mason is a co-founder and the chief science officer of Pascal.

Related stories:

Scientists build cooling system using solid refrigerants – 22 August 2022
USA: Scientists at Harvard University have built what is claimed to be a first-of-its-kind prototype cooling system using solid barocaloric refrigerants. Read more…