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Caeli Energie

Low-Consumption Indoor Air Cooling System Based on Thermodynamics


Rémi Perony

Mechanical engineer

Frédéric Micolon

CTO, Researcher

Stéphane Lips




Grenoble, France

Spring 2020


Caeli Energie is developing an innovative, residential air cooler with a low carbon footprint. The startup’s goal is to help people adapt to warming temperatures during the summer while raising awareness about climate change.

Quick facts
  • This past decade (2010-2020) has been the hottest decade in history. January 2020 was the hottest ever recorded for January. Climate scientists predict this trend is likely to speed up in upcoming years, and the consequences for humans are infinite.
  • As temperatures rise and heatwaves become more and more prevalent, the global demand for space cooling is booming. Cooling is the fastest growing use of energy in buildings. Energy demand for space cooling will more than triple by 2050.
  • Traditional (non-efficient) ACs leak refrigerants (strong greenhouse gases) into the atmosphere, which accelerates climate change.
  • Investing in more efficient ACs could reduce future cooling energy demand by 45%.

Sources: NASA, IEA

Their system is essentially an indirect adiabatic cooler that uses a high-performance heat-exchanger that lowers a room’s air temperature by extracting heat from hot air and exchanging it into evaporating water. It is inspired by the thermoregulation principle used by many mammals to control their own temperature. Compared to traditional vapor compression AC systems, Caeli’s prototype shows an energy efficiency that is 2-5 times higher without using any polluting refrigerants or chemicals. It is most effective in drier climates but the impact of this project could certainly be global, as many dry climates exist around the world.

“We belong to a new category of entrepreneurs who believe that tech must be use for the sake of the all. Entrepreneurship is the perfect way to maximize our career while having a positive impact on a large scale. When we first went on Stardust website and looked a the different projects they supported, it was obvious that despite the great variety of projects, they all shared one common feature: making the world more equitable and sustainable. That’s why we are now particularly proud to be part of the Stardust community.”

– Caeli Energie team

The $2,000 Stardust grant is funding attorney fees to become an official social/environmental impact company in France (entreprise à mission) as well as part of their annual B Corp Certification fees.

Update | July 2021

The Caeli team has been working hard amidst COVID restrictions and lockdowns. They are currently producing an improved prototype, hiring qualified engineers and interns, acquiring VC funds, and moving warehouse spaces! Read the full update here.