Retrofit at Rathaus-Center Pankow: 46% Energy Savings Through EC Fans and Digital Monitoring

The ventilation systems at Rathaus-Center Pankow (Berlin) were commissioned in the late 1990s. As part of the retrofit, 61 RadiPac EC fans replaced the previous belt-driven fans in nine units. The fans are installed in redundant FanGrid configurations, ensuring high availability. The EC drive provides stepless speed control depending on load, maintaining high efficiency at part-load conditions, which predominate in actual operation.

What Was Done in the Project

In parallel with the equipment replacement, the NEXAIRA.Fit digital extended configuration was implemented. Through a gateway, data on power consumption, speed, and runtime are collected; these are supplemented with temperature, CO₂, and volatile organic compound (VOC) values and transmitted to the cloud in encrypted form. A central dashboard provides transparency of unit operation.

How NEXAIRA Works

NEXAIRA is ebm-papst's digital ecosystem for ventilation and air-conditioning systems, combining high-efficiency EC fans with data-driven analytics and control. In ventilation and air-conditioning systems, the potential savings amount to up to 70% of fan energy costs. The system primarily uses existing operational and fan data, supplementing with additional sensors only when necessary. Features include demand-based airflow control, condition monitoring, vibration diagnostics, and detection of filter and heat-exchanger fouling. This enables maintenance planning based on actual need and avoids unplanned downtime. Unlike traditional monitoring systems that only signal when a set pressure-differential threshold is reached, the NEXAIRA approach allows prediction of the remaining time until the threshold is reached.

Results and Plans

Since commissioning in 2021 through 2025, a 46% energy saving, a reduction in CO₂ emissions of 130.41 t, and savings of approximately €76,000 have been achieved. The payback period is less than three years. Based on these results, the operator plans further retrofit phases.

Rising energy prices, regulatory requirements, and climate targets are increasing pressure on commercial building operators. Ventilation, heating, and air-conditioning systems offer significant savings potential, and this project demonstrates how existing installations can be optimised without capital construction.