# Webinar Replay: inside Airthium's engine, economics, and IP | Airthium (YC S17)

- Canonical URL: https://wefunder.com/feed/345599
- Entity ID: wefunder:feed_item:345599
- Published at: 2026-06-30 14:38:21 UTC
- Updated at: 2026-06-30 14:38:28 UTC

## Author
Franck Lahaye

## Subject
Airthium (YC S17)

## Content
Thank you to everyone who joined us live last week. For those who couldn't make it, we recorded everything - watch the full replay here →Here's a quick recap of what we covered:🔬 The engine. We walked through the thermodynamics of our system: a heat pump that produces up to 3x more heat than a resistive boiler for the same electricity input. That efficiency ratio is what makes us cost-competitive with natural gas, reaching up to 250°C, where most industrial processes live.⚡ Why hybrid wins. Our containerized system connects to a factory's existing gas boiler and, through software, switches in real time between electricity and gas depending on the price. When solar drives electricity prices down, we run. When electricity is expensive, the boiler takes over. Factories save from day one, no modifications to their floor plan.💰 How Heat-as-a-Service works. No upfront capital cost for the buyer. We own the machine, drop it on-site, and sell the heat at a price 10-20% below what the factory pays today. Some of the savings go to the customer; the rest funds our capex and margin. Our modeling shows payback windows of 6-8 years without grid services revenue - potentially 3-5 years once we factor that in.📍 Where we are. We finished testing our 1kW prototype at 145°C in December. We're now building the 10kW system, our next step before the pilot - a 100kW system at 200°C, under LOI with a chemical plant in eastern France, targeted for 2028.🔒 On competition and defensibility. Andreï addressed this directly: Stirling engines have been around for 200 years, but building them efficiently has been a challenge. We found a way to do this, and our liquid piston compression patent secures our moat.Investor interest is heating up after our webinar - early bird terms are now 60% sold out! Get in before the next milestone.🔥Invest or increase your investment at wefunder.com/airthium/invest Here's to building the future of factory heat — together.