The startup, Pascal, has raised $8 million from investors, Engine Ventures and Khosla Ventures, in order to develop high-efficiency, climate-friendly heat pumps, air conditioners, and refrigerators based on solid refrigerants. The investment will be used to commercialize Pascal's low-pressure, solid refrigerant-based system, which is tailored to meet commercial HVAC specifications. The company will also use the capital to expand its Boston-based team of mechanical engineers, chemists, and material scientists.

Currently, space and water heating, cooling, and refrigeration account for approximately 50% of electricity use in commercial buildings and over 70% in residential buildings. In addition to requiring substantial energy, today’s HVAC technologies – including heat pumps – rely on HFCs for cooling and refrigeration. An estimated 2% of total greenhouse gas emissions come from HFC leaks from HVAC systems.

Solid refrigerants provide a much-needed alternative to the sustainability challenges of gaseous refrigerants like HFCs, however historically, they’ve 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 specialized pressure vessels, pumps, and compressors, making them prohibitively expensive.

“Demand for HVAC is rapidly rising, with global energy demand for air conditioners alone expected to triple by 2050. At the same time, the HVAC industry faces significant regulatory and societal pressure to shift to using refrigerants with lower GWP,” explained Adam Slavney, co-founder and CEO of Pascal. “Heat pumps are a crucial tool for decarbonizing the HVAC industry, however, they rely on polluting HFCs and are more expensive than gas furnaces. Pascal is building a better heat pump based on solid refrigerants that will deliver higher efficiencies at lower costs, while eliminating all refrigerant emissions.”

Pascal’s novel class of solid refrigerants operates at lower pressures than previously possible and 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. Companies operating in the commercial refrigeration supply chain, and any organization with heating and cooling needs across distributed locations can benefit from Pascal’s technology, which offers:

  • Zero direct refrigerant emissions;
  • A 50% to 80% improvement in energy efficiency;
  • Smaller, quieter, and safer systems; and
  • A direct interface with standard HVAC components.

“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.

“With demand for clean electrons surging, but constraints on their access biting, solutions that increase efficiency and drive down HVAC electrical loads and costs are critical to meeting our energy transition goals. Accomplishing that and removing 2% of greenhouse gas-equivalent emissions from HFCs is a win-win,” added Michael Kearney, general partner at Engine Ventures. “We are thrilled to support this team as they build a business around their transformative materials and chemistry-based discoveries.”

“The scale of the HVAC sector's greenhouse gas emissions is on par with other massive categories like global aviation. Yet as our world warms, cooling becomes a survival tool,” said Jessy Rivest, partner at Khosla Ventures. “Pascal’s pioneering technology stands poised to tackle both the emissions and survival challenges, innovating for a cooler, cleaner future.”