The ELI-NP facility covers an area of approx. 33,000 m2 of high quality, energy efficient buildings, mostly dedicated to the high-power laser system, gamma-beam production system and instrumentation for experiments, but also to offices, guest house and canteen buildings. The state-of-the-art scientific equipment requires special clean-rooms, and specific temperature and humidity conditions and hence first-class utilities and operation. An important part of the electric energy consumption is generated via a system of geothermal pumps, the biggest of its kind in Europe, connected to a ground heat exchanger system consisting of 1080 wells 120 m deep. The HVAC system covers a climatized area of more than 21,000 m2 and is designed to operate 24/7/365 via an intelligent microprocessor control system. The system thus ensures an operational cost economy of more than 625,000 Euro per year while also delivering best quality services.