Tactical ventilation

Tactical ventilation or smoke extraction called in the fire department an operational tactics of targeted ventilation in case of fire .

Goal and concept

Ventilation with fan on telescopic crane during tests of the NIST

Indoor smoke is a problem in fire fighting for several reasons . The obstruction of view makes orientation, rescuing people and fighting fires more difficult. Flue gas is highly toxic and can lead to life-threatening smoke poisoning. Thanks to their breathing apparatus, fire fighters do not breathe in the smoke gases; however, their protective clothing will be contaminated. Smoke causes property damage in buildings and can ignite flammable substances with its thermal energy and thus contribute to the spread of fire.

The aim of tactical ventilation is to quickly remove a lot of smoke from the building near the source of the fire and to lower the temperature. This should facilitate search and rescue measures, reduce the risk of smoke and smoke gas explosions and slow down the spread of fire.

The danger of tactical ventilation is that additional oxygen is added to the fire, which can make the fire worse. The smoke should be swirled with air as little as possible in order to avoid an ignitable mixture . For example, the fact that there is no smoke vent, that there are people between the source of the fire and the vent or that there are signs of an impending smoke explosion can speak against ventilation . In this case, blocking ventilation by closing doors or windows can prevent fire and smoke from spreading.

species

Use of a high pressure aerator

Natural ventilation

In the event of a fire, smoke that is lighter (because it is warm) and under excess pressure is produced. As soon as there is an opening in the building, a natural draft is created. This can be achieved by activating a smoke outlet , opening or smashing windows or opening the roof, for example by removing roof tiles with an aerial rescue vehicle .

Pressure smoke extraction

Pressure ventilators are used for pressure smoke extraction in order to convey air with overpressure into the building at specific points . If the inlet and outlet openings are the correct size, the air will be forced out through the outlet. One danger is that the smoke will be pushed deeper into the building. As soon as the fire has been extinguished, it is recommended to ventilate the rooms of an apartment gradually in order to achieve the most effective smoke extraction possible. A fan can move around 1000 m³ of air per minute.

In contrast, with overpressure ventilation no or only a small exhaust air opening is created so that permanent overpressure is created. This means that adjacent buildings or stairwells can be kept smoke-free.

Hydraulic ventilation

hydraulic ventilation

With hydraulic ventilation, water is transported out of doors or windows into the open with a spray jet , whereby the entire opening should be filled by the water jet. Using the Venturi effect , the smoke is carried away and drawn out of the building. With a water flow of 200 liters, around 45 m³ of air can be moved per minute by means of hydraulic ventilation. Compared to a pressurized aerator, this is not very effective and it is associated with high water consumption; however, the hydraulic ventilation can support the other two concepts or be used to extract smoke from smaller rooms.

Web links

Commons : Ventilation (firefighting) - Collection of images

rescuetec112: Respiratory protection - Tactical ventilation on YouTube , April 26, 2012.
WDR , Series Fire & Flame , Season 2: Black smoke in the hallway (from 0:11:20) on YouTube , January 26, 2019 (hydraulic ventilation in a cellar fire).

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Ulrich Cimolino: Operations and section management: the operations management system . ecomed-Storck, 2009, ISBN 978-3-609-61151-8 , pp. 318-323.
↑ Ulrich Cimolino : Respiratory protection emergency management: organization, training and equipment for security teams and rapid response teams . ecomed-Storck, 2010, ISBN 978-3-609-77484-8 , p. 111.
↑ ^a ^b ^c Ulrich Cimolino, Christian Emrich, Stefan Svensson: Tactical ventilation: ventilation systems in action . ecomed-Storck, 2012, ISBN 978-3-609-68426-0 , chapter 8.
↑ ^a ^b ^c Holger de Vries: Use of hollow jet pipes , ecomed-Storck 2017, ISBN 978-3-6096-9643-0 , p. 89.

[cimolino-1] ↑ ^a ^b ^c ^d ^e ^f Ulrich Cimolino: Operations and section management: the operations management system . ecomed-Storck, 2009, ISBN 978-3-609-61151-8 , pp. 318-323.

[2] Ulrich Cimolino : Respiratory protection emergency management: organization, training and equipment for security teams and rapid response teams . ecomed-Storck, 2010, ISBN 978-3-609-77484-8 , p. 111.

[emrich-3] Ulrich Cimolino, Christian Emrich, Stefan Svensson: Tactical ventilation: ventilation systems in action . ecomed-Storck, 2012, ISBN 978-3-609-68426-0 , chapter 8.

[holger-4] Holger de Vries: Use of hollow jet pipes , ecomed-Storck 2017, ISBN 978-3-6096-9643-0 , p. 89.