Where many air-cooling architectures release excess heat into the atmosphere, ours is designed to reuse it. In Mäntsälä, Finland, waste heat generated by servers is captured and fed into the local district heating system. The project was phased in 2015-2016, making us one of the first to implement such technology in the region, and the very first in Finland.

In the past two years, the facility supplied over 30 GWh of heat — covering up to 72% of the town’s annual heating demand, even as we operated below full capacity during a period of business transformation. In 2024 alone, this reduced local heating-related emissions by 54%, by an estimated 3,220 tonnes of CO₂ equivalent. With the ongoing expansion, the system has the potential to deliver even greater volumes of recovered heat in the years ahead.

The heat recovery process is fully integrated into the data center’s architecture. Hot air from the server rooms is passed through air-to-water heat exchangers, where it is used to raise water temperatures to 35-40°C (95-105°F). The municipality then boosts the temperature further to the standard 55-60°C (130-150°F) before transferring it to the local network for distribution. The system is automated and monitored continuously to ensure consistent performance and efficient energy transfer.

At our partner-operated facility in Paris, heat recovery infrastructure has been introduced to supply energy to the city’s district heating network. Already, the system already warms a rooftop greenhouse, where tomatoes and other produce flourish year-round. Upon harvest, this is delivered to associations that work with communities struggling with food access.

By treating heat as a resource, rather than a byproduct, we are able to reduce emissions, improve local energy resilience and extend the environmental value of the energy already used for compute.