Outstanding HVAC flexibility after high-end office building renovation

Many office buildings constructed in the 1970s and 80s await a critical decision about their future existence. A good example can be found in Dusseldorf, Germany where a building owner has decided for a shell & core renovation, only leaving the main structure of the building in place. The basically completely new office building got a state of the art HVAC system for heating and cooling, providing all the flexibility required for both the office workers and technicians.

One of the important requirements for the building owner was to obtain a certification from the DGNB (German Sustainable Building Council). Furthermore, the layout for the new office spaces inside the ten-story building were unknown and required a high level of flexibility to fulfill the wishes of future renters.

This scope provided ENGIE, the assigned responsible for the entire HVAC system in the building, a challenge to solve. In cooperation with Danfoss GmbH they found a perfect solution.

The office building was equipped with a Building Management System (BMS) and 457 ceiling panels providing the offices both heating and cooling via a 4-pipe change-over system. To balance the system hydronically the panels are equipped with AB-QM Pressure Independent Balancing and Control Valves. They provide an energy efficient hydronic solution and are also used to control the flow demand. To control the room temperature the valves are equipped with the digital NovoCon^® actuators. The actuators are directly connected to the BACnet operated BMS system and provide many benefits. Most importantly, the required flexibility in the HVAC design is ensured. In case of office space changes, the actuators can remotely be re-assigned to another space. Furthermore, the system data that becomes available for the BMS system provides detailed insight of the status and e.g. allows predictive maintenance.

To optimize the heating and cooling sequence it was decided to add Danfoss ChangeOver6 actuator mounted on a 6-way valve into the concept. In case of a change from heating to cooling or vice-versa, the NovoCon^® actuator ensures a new design flow value and steers the 6-way valve to change position, allowing either warm or cold water to enter the Heating/Cooling panel.

The innovative NovoCon^® concept has proven to be a time-saving, flexible and most cost-effective solution for the project.