The global expansion of data center construction is fueled by the rising demand for AI applications. These energy-intensive facilities face increasing pressure to operate efficiently due to the European Efficiency Directive (ENER, 2024), for instance. Minimizing their environmental impact is therefore critical. To address this challenge, the System Simulation team in Danfoss Climate Solutions and TLK Energy are focusing in this joint presentation on innovative heat recovery approaches in modern, liquid-cooled data centers as a key strategy for energy-efficient operation. Using a holistic model of the overall system from liquid cooled server racks via the cooling loop to chillers, dry coolers and heat recovery including heat consumers, we can determine the system efficiency covering all interactions of the sub-systems for fully transient conditions. The backbone of the system models are the validated models of the relevant components from Danfoss’ portfolio. By setting the simulation results in relation to the needed CAPEX we are going to draw a picture of an optimized system setup for the presented use case.