Innovation meets architectural heritage preservation: One of the world's oldest police station – located in Great Britain – has been undergoing extensive renovation since January 2025 and is being equipped with state-of-the-art fire protection technology from AQUASYS. In cooperation with the local partner, an innovative high pressure water mist system is being used that preserves the historic character of the building while meeting the highest safety requirements.

The challenge of historic buildings

The protected site places high demands on the technology: the fire protection solution must not only cover hard-to-reach cavities and technical installations, but also must not impair the historic fabric of the building. Specially developed nozzle types are therefore used: DKF35 for standard rooms and DKF34 for areas with ceiling heights of more than four metres – for maximum efficiency with minimum intervention.

Innovative tests for demanding conditions

A key issue was the interaction between water mist and ventilation systems. According to the standard (BS 8489-1), ventilation systems should be switched off in the case of fire so as not to interfere with the effectiveness of the water mist. However, this is not possible at the police station – here, the ventilation must remain active even in an emergency in order to comply with the regulations for office (Ordinary Hazard 1) and technical rooms (OH3).

AQUASYS therefore developed a special test program in collaboration with the local partner. A real room with variable ventilation systems was recreated in the company's own demonstration room. Various air flow speeds (0.33 m³/s and 0.67 m³/s) were investigated in order to simulate the effect on the distribution of the water mist in a realistic manner.

New standards for fire protection in historic buildings

The results of the tests prove that even with active ventilation, the high pressure water mist system meets all requirements – without compromising protection or interfering with the historic fabric. The project thus impressively demonstrates how state-of-the-art safety technology and monument protection can be successfully combined.