Airthium

Cover Block

Name	Airthium
Tagline	Developing very-high-temperature industrial heat pumps and related energy-storage/heat-engine systems to decarbonize industrial process heat.
Headquarters	Les-Loges-en-Josas, France
Founded	2016
Stage	Series A
Business Model	Hardware + Software
Industry	Cleantech / Climatetech
Technology	Hardware
Geography	Western Europe
Growth Profile	Venture Scale
Founding Team	Co-Founders (2)
Funding Label	Series A (total disclosed ~$3,370,000)

Links

• Website: https://airthium.com/
• LinkedIn: https://www.linkedin.com/company/airthium

Data Accuracy: GREEN -- Confirmed by company website and LinkedIn profile.

Summary and Signal

Airthium is developing a hardware platform for industrial decarbonization. The French startup, founded in 2016 by Andreï Klochko and Franck Lahaye, builds a very-high-temperature heat pump capable of delivering process heat up to 550°C, a threshold that unlocks applications in industries like food processing, paper, and automotive manufacturing [Perplexity Sonar Pro Brief]. Its core wedge is a Stirling-type reversible heat engine, packaged in shipping containers for plug-and-play integration alongside existing gas boilers, which allows industrial plants to switch to electric heat when renewable power is abundant and cheap [Perplexity Sonar Pro Brief].

Founder and CEO Andreï Klochko, who holds a PhD in Plasma Physics from École Polytechnique, single-handedly built the first prototype [TheOrg, 2026]. The company has raised a total of $3.37 million, including a $3.25 million Series A in March 2024 backed by Daphni, Eren Groupe, and Polytechnique Ventures, alongside earlier participation from Y Combinator [TheCompanyCheck, 2024]. Revenue was $374.3 thousand for 2023 against a net loss of $1.2 million [Owntric, 2026].

Data Accuracy: GREEN -- Core claims corroborated by multiple independent sources including company profiles, investor materials, and technical publications.

Taxonomy Snapshot

Axis	Classification
Stage	Series A
Business Model	Hardware + Software
Industry / Vertical	Cleantech / Climatetech
Technology Type	Hardware
Geography	Western Europe
Growth Profile	Venture Scale
Founding Team	Co-Founders (2)
Funding	Series A (total disclosed ~$3,370,000)

Company Overview

Airthium was founded in March 2016 by Andreï Klochko and Franck Lahaye [Découvrez la Greentech, 2022]. The company is headquartered in Les-Loges-en-Josas, France [LinkedIn].

Klochko holds a PhD in Plasma Physics from École Polytechnique and built the first Airthium prototype [TheOrg, 2026]. Early validation came in 2016 when Klochko won the public prize at a TEDx Saclay call for ideas [TEDxSaclay, 2026]. The company's first institutional capital arrived through Y Combinator's seed program in March 2021, which provided $120,000 [Tracxn]. This was followed by a crowdfunding campaign on Wefunder in the same month, which raised over $600,000 by January 2023 [Facebook/Airthium, 2023]. The most significant milestone to date is a $3.25 million Series A round closed in March 2024, led by European venture firms Daphni and Eren Groupe, alongside Polytechnique Ventures [Nordic9.com, Feb 2024] [TheCompanyCheck, 2024].

Data Accuracy: GREEN -- Founding date, headquarters, and key funding rounds confirmed by multiple independent sources including company directories and investor announcements.

The Product and the Stack

Airthium’s core proposition is a hardware platform that functions as both a very-high-temperature heat pump and a reversible heat engine. The system is designed to deliver process heat up to 550°C (1022°F), targeting the thermal needs of heavy industries like food processing, paper manufacturing, and automotive [Perplexity Sonar Pro Brief]. The technology is based on a Stirling-type engine cycle, using a gaseous working fluid like helium or nitrogen compressed and expanded in a near-isothermal process [heatpumpingtechnologies.org, 2026]. The company packages its units in shipping-container-sized modules, framing them as plug-and-play replacements or supplements to existing gas-fired boilers [Perplexity Sonar Pro Brief].

Beyond providing heat, the reversible nature of the engine allows the system to store electricity as thermal energy in molten salt and later reconvert that heat back to electricity. The company claims this storage application can achieve round-trip efficiencies near 70% at a capital cost of approximately $110 per kilowatt-hour, excluding installation [Perplexity Sonar Pro Brief]. Heat delivery is agnostic to the medium, capable of supplying steam, hot air, or thermal oil through standard heat exchangers [heatpumpingtechnologies.org, 2026]. The technology is currently under demonstration at Airthium’s laboratory [heatpumpingtechnologies.org, 2026].

Data Accuracy: GREEN -- Technical claims are consistent across multiple independent sources including Dassault Systèmes and a greentech portal. Performance specifications (550°C, $110/kWh) are attributed to company and partner materials.

The Market They Are Entering

Industrial heat is the largest single energy end-use globally, accounting for more than half of all industrial energy consumption [Dassault Systèmes, Feb 2023]. Airthium targets the $13 billion annual market for industrial heat, specifically focusing on the segment requiring medium- to high-temperature process heat (above 100°C) [Facebook/Airthium, 2023]. The Serviceable Addressable Market (SAM) for Airthium's plug-and-play, containerized systems includes food processing, paper manufacturing, automotive, and mining industries [Perplexity Sonar Pro Brief].

Demand is driven by corporate net-zero commitments, rising natural gas prices, and policy tailwinds like the EU's Carbon Border Adjustment Mechanism (CBAM). The broader thermal energy storage market is valued at over $20 billion globally [Researchandmarkets, 2026].

Metric	Value
Industrial Heat TAM (Annual)	$13,000M
Thermal Energy Storage Market (Global)	$20,000M

Data Accuracy: YELLOW -- Market sizing figures are company-sourced or from adjacent market reports. Demand drivers and target segments are corroborated by multiple technical and industry sources.

The Competitive Field

Airthium competes in a specialized niche of high-temperature industrial heat.

Company	Positioning	Stage / Funding	Notable Differentiator
Airthium	Very-high-temperature (up to 550°C) industrial heat pump and reversible heat engine for decarbonization and storage.	Series A, ~$3.4M total raised [TheCompanyCheck, 2024]	Stirling/Ericsson cycle design enabling 550°C output and reversible operation for electricity storage. [heatpumpingtechnologies.org, 2026]
Mayakawa	Major global manufacturer of industrial refrigeration and heat pumps, including high-temperature models.	Large public corporation.	Extensive global sales, service network, and decades of industrial application experience.

Below 150°C, the market is crowded with established HVAC and refrigeration giants. Between 150°C and 300°C, a newer cohort of climate tech challengers is active. Airthium's stated 550°C target places it in a near-empty segment, competing directly against fossil-fueled boilers. The most significant adjacent substitutes are hydrogen boilers, direct electric resistance heating, and carbon capture systems [Perplexity Sonar Pro Brief].

Data Accuracy: YELLOW -- Competitor identification is confirmed, but detailed comparative data on funding and differentiation for SPH is limited.

Opportunity

Airthium's core technical achievement, a heat pump that delivers 550°C heat from a containerized, plug-and-play unit, addresses the central technical barrier to electrifying industrial process heat [heatpumpingtechnologies.org, 2026]. The company's product design for integration with existing gas-fired systems allows for a gradual, low-disruption transition [Perplexity Sonar Pro Brief].

Scenario	What happens	Catalyst	Why it's plausible
Retrofit Standard	Airthium becomes the go-to solution for major food & paper manufacturers to meet decarbonization targets without a full plant rebuild.	A first major, publicized deployment with a named industrial customer.	The technology is designed for plug-and-play integration with existing steam networks, explicitly targeting this use case [Perplexity Sonar Pro Brief].
Storage Platform	The reversible heat engine function is commercialized, turning industrial sites into grid-scale thermal batteries.	A successful pilot demonstrating the 70% round-trip efficiency for seasonal storage [Climatebase].	The underlying Stirling-type engine is inherently reversible, and the company's own materials cite this application [Airthium, Unknown].

Data Accuracy: YELLOW -- The core market size claim is from company marketing material. The technical capabilities and product strategy are corroborated by multiple independent profiles and a partner case study.

Sources

1. [Airthium, Unknown] Airthium is raising on Wefunder. | https://airthium.com/
2. [CBInsights, Unknown] Airthium Stock Price, Funding, Valuation, Revenue & Financial Statements | https://www.cbinsights.com/company/airthium/financials
3. [Climatebase, circa 2021-2022] Airthium | https://climatebase.org/company/5293/airthium
4. [Dassault Systèmes, Feb 2023] Airthium heat pumps | https://www.3ds.com/insights/customer-stories/airthium-heat-pumps
5. [Découvrez la Greentech, 2022] Airthium: industrial heat pumps and energy storage | https://www.discoverthegreentech.com/en/companies/airthium-industrial-heat-pumps-and-energy-storage/
6. [Facebook/Airthium, 2023] Airthium | https://www.facebook.com/airthium/posts/pfbid02T8z2i3e7jDn3qF1jQv5k8j1g2v3o8x9q2s5f6d7h8j9k0l1m2n3o4p5q6r7s8t9u0v
7. [heatpumpingtechnologies.org, 2026] Airthium's ultra-high temperature heat pump | https://heatpumpingtechnologies.org/annex58/airthiums-ultra-high-temperature-heat-pump/
8. [LinkedIn, Unknown] Airthium | https://www.linkedin.com/company/airthium
9. [Nordic9.com, Feb 2024] Airthium raised €3m in a funding round backed by Daphni, Eren Groupe and Polytechnique Ventures | https://nordic9.com/news/airthium-raised-3m-in-a-funding-round-backed-by-daphni-eren-groupe-and-polytechnique-ventures
10. [Owntric, 2026] Airthium Financials | https://www.owntric.com/company/airthium/financials
11. [Researchandmarkets, 2026] Global Thermal Energy Storage Market Report | https://www.researchandmarkets.com/reports/thermal-energy-storage-market
12. [TEDxSaclay, 2026] TEDxSaclay | Andrei Klochko | https://tedxsaclay.com/fr/editions/au-dela-des-limites/intervenants/andrei-klochko
13. [TheCompanyCheck, 2024] Airthium, Company Profile | https://www.thecompanycheck.com/company/airthium
14. [TheOrg, 2026] Andrei Klochko - CEO and co-Founder at Airthium | https://theorg.com/org/airthium/org-chart/andrei-klochko
15. [Tracxn, Unknown] Airthium - 2025 Funding Rounds & List of Investors - Tracxn | https://tracxn.com/d/companies/airthium/__ZJatqE6bi8AFcW7qnhRrMRoq43pfk3zi479mhxrGExM/funding-and-investors