Why positive pressure ventilation?
“Fight fire with a fan, not with water!” Statements like this always lead to heated discussions. However, there is a simple principle behind this. In order to survive, people who are exposed to toxic fire smoke need fresh air more than anything. And it is precisely this supply of fresh air that is created by means of positive pressure ventilation – when used correctly. Another feature of this firefighting method is the easier and therefore faster advancement of the SCBA crew due to improved visibility, which significantly increases the likelihood of a safe and successful operation
What fans exist, and what are the differences?
Mobile small fans, i.e., fans that can be manually moved by firefighters are usually differentiated based on the type of drive. Here classic combustion engines are used on the one hand, and electric motors on the other. Water-driven fans now play a subordinate role, largely due to the high set-up efforts involved. A general trend toward battery-powered appliances has emerged in recent years. Fans with outlet diameters from 16 to 22 inches are most commonly used.
Which type of fan would best suit me?
This question isn’t so easy to answer.
If air performance in absolute terms is of utmost importance, then a fan with an internal combustion engine is the answer. Devices with this type of drive are by far the most powerful. However, they also have disadvantages, such as being very loud, and the possible entry of exhaust gases into the building.
Fans driven by an electric motor overcome these disadvantages. They have the advantage that they can be used in any scenario, because no gasoline can leak, for example. In addition, no exhaust gases are produced, and this type of fan is therefore clearly more environmentally friendly to use – even inside buildings. However, an external power supply is required.
Battery-powered fans also belong to the category of electric fans. Thanks to the battery technology used, the fans can be used independently, i.e., no external power supply is needed, at least on a temporary basis. This is definitely the fastest method by which to ventilate. Another advantage of battery-powered fans: they are a lot lighter than devices with other drive types and can therefore be repositioned much more easily.
In order to be able to make a recommendation, various factors need to be considered. In addition to the dimensions available in the equipment compartments, the weight and performance class and the accessories available are essential selection criteria. However, if the flexibility to cover different operational scenarios is a key consideration, then battery-powered fans stand out as a clear winner. They can be put into operation the quickest and can be used either as a main fan or as an auxiliary fan inside buildings. When it comes to handling in difficult places, for example stairwells, the emergency personnel benefit from the enormous weight advantage and their mobility makes positioning for shaft ventilation as easy as it gets.