Control and suppression of sauna fires by water-mist systems

Saunas are currently included in many facilities and require dedicated fire-protection systems, since short circuits and direct contact with incandescent materials may start a fire involving timber, fabric and chemicals. In this frame, assessing the capabilities of water mist is the major scope of the present work. A real-scale setup was built and equipped with thermocouples and a hot-plate thermometer to evaluate control and suppression performance. Timber benches were inserted and the fire was initiated in a wood crib. The system successfully controlled and contained the fire, as the bench damage ratio was always kept below 5%. However, extinction was not achieved in 2 cases and notably in the supposed most challenging configuration in terms of ventilation, initial room temperature and nozzle-to-wall distance. On the other hand, ignition-source location, wood-crib damage ratio and air-gap between benches and walls did not affect suppression performance.