PPV EXTINGUISHING TECHNIQUE
A fire involving rubber tyres giving off high energy combustible gases (smoke) in a bedroom on the upper floor of this derelict two storey house in Valencia County, Spain, has gone into decay (RICH) because the wooden window shutters and entrance door have been closed following the Lean Flashover stage.
All the doors from the front door on the lower floor leading up the stairs to the closed bedroom door are all open.
A ladder has been positioned adjacent to the bedroom shutters.
One Fire-Fighting (FF) Crew is positioned with a Fogfighter Nozzle outside the fire room door ready to enter.
Another FF Crew is positioned adjacent to the PPV Fan pointing at the open front door ready to deploy the PPV Fan upon the opening up of both the bedroom shutters and door.
Then, a Fire-fighter ascends the ladder and opens the bedroom shutters, whilst simultaneously the FF Crew outside the fire room open the bedroom door and begin to apply water spray droplets into the room. Then, the FF Crew at the front door deploy the PPV Fan and force positive pressure air through the front door and up the stairs into the bedroom.
Watch the outcome of these techniques in glorious technicolor.
Thermocouples were positioned inside the fire room and following the deployment of the PPV Fan the temperatures inside the room reduced even though it appears to flame up at the window.
Why is this possible, could it be that cold air has similar heat absorption (BTU’s) capabilities as that of water spray droplets and takes away one side of the triangle of fire – HEAT, is this not just like blowing out a candle.
However, there are other factors to take into account before deploying these tactics and you should not try using these tactics without being fully practically trained in approved ATM fire-fighting Techniques TM.
A full explanation of this technique and it’s operational application/implications are available in the book – Smoke Burns.
John Taylor 12 August 2015