Digital Actuators Optimize HVAC for Gas-Free Building

The Provinciehuis Overijssel in Zwolle, the Netherlands, was built in 1972 as one of the first regional government facilities to feature large open-plan workspaces accommodating approximately 1,000 employees. To support the region's ambition to become completely energy-neutral, the building management needed to transition from a traditional climate control system utilizing gas-fired boilers and low-temperature heat pumps to a fully gas-free setup. A major technical challenge was the requirement to execute this transition without major structural modifications, specifically aiming to retain the existing terminal units such as radiators, convectors, and ceiling induction units. These existing legacy units required higher supply temperatures, complicating the integration of a sustainable heating solution.

Implementing data-driven digital control technology
The facility faces widely varying occupancy levels due to hybrid working arrangements, making it critical to accurately monitor and automatically optimize energy consumption and climate control. Furthermore, regional regulations mandated the implementation of a Building Automation and Control System to reduce energy consumption and improve operational efficiency. To meet these demands, the installation company Heijmans and smart-building specialist bGrid collaborated with Danfoss to deploy a future-ready technical solution. The gas-fired central heating boilers were replaced with a heat pump utilizing natural refrigerants. To control the hydronic ceiling units precisely, the engineering team integrated Danfoss pressure-independent control valves combined with digital actuators. This configuration creates a dynamically balanced and self-optimizing HVAC network capable of handling fluctuating thermal loads.




Reduced energy consumption and operational insights
Data from the smart sensors and controllers is collected, stored, and visualized through a dedicated building management platform. This infrastructure provides building managers with floor-level insights into space occupancy, energy use, and system performance, allowing the climate control system to automatically respond to actual room usage. The deployment of this smart digital control architecture has yielded measurable operational results. The modernized system consumes approximately one-third of the energy required by the former gas boiler setup, resulting in a reduction of 200,000 kWh of gas energy annually alongside a 10 percent decrease in electricity costs. Matching equipment performance to actual occupancy, such as shutting down climate control on unused floors during low-attendance days, cuts energy consumption by more than 25 percent. Additionally, indoor comfort improved significantly, reflected in an 80 percent reduction in climate-related complaints, while operators gained the ability to continuously monitor deviations and maintain optimal indoor air quality.

Edited by Maria Brueva, Induportals editor – adapted by AI.

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