Deliverable D3.2 investigates how much of the heat produced by data centres can realistically be reused for heating buildings, or even whole neighborhoods. It combines data-driven analysis with design-based estimation across four pilot sites: AAU (Denmark), EMPA (Switzerland), TOFAS (Turkey), and PSNC (Poland).

How was it done? The report introduces a six-step methodology to evaluate waste heat utilization potential. The method considers operational data, temperature requirements, energy needs, and how these vary by system, time of day, and season.

Key findings from the pilots:

AAU can cover up to 79% of its heating needs using waste heat when supplied at the system level (rather than via the main heating supply), particularly for underfloor heating and ventilation.

EMPA’s NEST building showed high reuse potential due to its low-temperature thermal networks and modular setup, making it ideal for integrating future heat sources.

TOFAS showed seasonal reuse opportunities in its IT office, where fan coil systems could be powered by waste heat for much of the year.

PSNC already reuses some waste heat but lacks sufficient monitoring points for detailed analysis. Future upgrades (like switching to liquid cooling) could significantly boost its recovery potential.

Beyond buildings — What about cities? A major highlight is the scalability of heat reuse. The deliverable outlines a tool to estimate when it makes economic sense to feed excess heat into a district heating network, considering investment cost, fuel prices, temperature levels, and infrastructure distance.

Bottom line: The better the data and temperature alignment between systems, the higher the reuse potential. Even modern buildings often miss the right sensors to evaluate this fully, a gap HEATWISE helps to fill. With smart upgrades and integration, data centre waste heat could help power the buildings and cities of tomorrow.