Qarnot raises €6m to heat buildings in France with servers

2 Apr 2020

A Qarnot radiator inside a home. Image: Qarnot

Qarnot has raised fresh funding for its platform that uses computer servers to heat buildings.

French computing start-up Qarnot has announced that it closed a €6m Series B round, which will fund the company’s climate-conscious cloud computing solution that uses the heat generated from servers to boil water and heat properties.

Participants in the funding round include Banque Des Territoires, Caisse des Dépôts, Engine Rassembleur d’Énergies, A/O PropTech and Groupe Casino. Qarnot’s president, Paul Benoit, said that the funding will be used to continue R&D operations and expand sales.


The start-up is already using its solution to heat nearly 1,000 social housing units in France for free. Because heating is not needed all year round in most climates, the start-up has also developed a solution that uses the heat from servers to boil water.

The QB1 digital boiler captures heat released from 24 different servers. This product is aimed at large commercial buildings that require hot water for taps.

A climate-conscious solution

Around the world, concerns are growing about the environmental impact that data centres and servers are creating. In 2015, the world’s data centres used more than Britain’s total electricity consumption.

Irish journalist Phillip Boucher-Hayes recently looked at the impact that Ireland’s data centres have on the country’s carbon footprint. “In seven years’ time, they will use a third of all electricity generated here. They will also be creating a minimum of 1.5m new tons of CO2,” he said.

Much of the electricity used in data centres is used to cool down servers, which generate a great amount of heat. Rather than fighting the heat, Qarnot wants to use it elsewhere.

Working with other businesses

Qarnot’s goal is to take the heat generated by servers and use it to heat houses, offices and public buildings, rather than letting it go to waste.

Qarnot’s heaters have been rented by companies including BNP Paribas, Sociétie Générale and Natixis, according to TechCrunch. Qarnot also recently secured a partnership with Illumination Mac Guff, the Paris animation studio behind the Despicable Me films.

The start-up also sells its computing heaters, which are electrical heaters containing servers, to construction companies to place in new buildings. The heat can be controlled by residents or people working in those buildings through a mobile app or a panel attached to the heater.

Kelly Earley was a journalist with Silicon Republic