An Open Standard for Useful Energy.
HotSide Collective is an open-source infrastructure project that defines a standardized way to recover waste heat from liquid-cooled computing systems and convert it into usable energy for buildings and communities. It treats data centers not just as computational resources, but as continuous sources of thermal energy that can be safely captured and redistributed through hydronic systems. The goal is to make heat recovery a reproducible, inspectable, and widely deployable layer of modern infrastructure rather than a custom, one-off engineering solution.
At its core, HotSide Collective provides a modular heat recovery architecture built around isolated dual-loop systems. A primary loop interfaces with liquid-cooled compute hardware, while a fully separated secondary loop delivers heat to building systems such as radiant floors, domestic hot water preheating, greenhouses, or district heating networks. Between them sits a standardized heat exchanger skid designed for scalability, maintainability, and safe operation under varying thermal loads.
The project also defines an open control and instrumentation stack that manages pumps, valves, and flow behavior in real time. It includes sensor frameworks for temperature, pressure, and flow monitoring, along with control logic that prioritizes compute stability above all else. The system is designed to fail safely, automatically isolating itself or bypassing heat transfer if operating conditions move outside defined safety envelopes.
Beyond hardware, HotSide Collective establishes a full open standard for thermal interoperability. This includes mechanical reference designs, electrical control panel guidelines, communication protocols like Modbus and BACnet, and simulation tools for sizing and validating deployments. By combining these layers into a single open framework, the project aims to enable universities, municipalities, and infrastructure operators to deploy heat recovery systems without relying on proprietary vendor ecosystems or closed industrial designs.
- HotSide Collective – An open-source thermal infrastructure standard that enables safe recovery of waste heat from liquid-cooled compute systems and converts it into usable energy for buildings and district heating networks.