Conversely, hydraulic ventilation can be performed by the nozzle team immediately after the fire is knocked down. Quick ventilation after the knockdown improves survivability for trapped occupants, and makes it quicker and easier to search for victims and fire extension. A 2,000 square foot house with 8 foot ceilings contains about 16,000 cubic feet of air space. A nozzle with a 30 degree fog pattern moving 6,000 cubic feet of air per minute can complete a full air exchange in the house in about 2 1/2 minutes; probably quicker than it will take to set up PPV. So next time you knock the fire down, consider using hydraulic ventilation before calling for the fan. As you will notice in the video, start out with a straight stream through the window then open the pattern until it fills most of the window and you are getting good smoke movement. Beginning this way ensures that all of the water goes out the window and prevents unnecessary water damage. Whenever using any kind of forced ventilation, frequently check behind you to make sure that the air flow is not causing fire to flare back up between you and your path of egress.
Monday, December 23, 2013
Hydraulic Ventilation: Another Forgotton Skill
It seems that nobody uses hydraulic ventilation anymore. Maybe it is misinformation, or maybe it just isn't covered adequately in recruit school; but hydraulic ventilation can be a very valuable tactic when used correctly. It seems that everyone is quick to call for PPV as soon as the fire is knocked down, without even considering using the nozzle to ventilate the fire area. Our PPV fans will move about 10,000-15,000 cubic feet of air per minute, while a 30 degree fog pattern will move about 6,000 cubic feet of air per minute. That's not a bad tradeoff when you consider that hydraulic ventilation is literally right at your fingertips. PPV takes time and personnel to set up. Doors must be closed to create a positive pressure and control the flow path. Most importantly, if there is fire extension into the attic or void spaces, PPV can turn a good stop into a total loss very quickly. Remember to always check the attic before initiating PPV.
Conversely, hydraulic ventilation can be performed by the nozzle team immediately after the fire is knocked down. Quick ventilation after the knockdown improves survivability for trapped occupants, and makes it quicker and easier to search for victims and fire extension. A 2,000 square foot house with 8 foot ceilings contains about 16,000 cubic feet of air space. A nozzle with a 30 degree fog pattern moving 6,000 cubic feet of air per minute can complete a full air exchange in the house in about 2 1/2 minutes; probably quicker than it will take to set up PPV. So next time you knock the fire down, consider using hydraulic ventilation before calling for the fan. As you will notice in the video, start out with a straight stream through the window then open the pattern until it fills most of the window and you are getting good smoke movement. Beginning this way ensures that all of the water goes out the window and prevents unnecessary water damage. Whenever using any kind of forced ventilation, frequently check behind you to make sure that the air flow is not causing fire to flare back up between you and your path of egress.
Conversely, hydraulic ventilation can be performed by the nozzle team immediately after the fire is knocked down. Quick ventilation after the knockdown improves survivability for trapped occupants, and makes it quicker and easier to search for victims and fire extension. A 2,000 square foot house with 8 foot ceilings contains about 16,000 cubic feet of air space. A nozzle with a 30 degree fog pattern moving 6,000 cubic feet of air per minute can complete a full air exchange in the house in about 2 1/2 minutes; probably quicker than it will take to set up PPV. So next time you knock the fire down, consider using hydraulic ventilation before calling for the fan. As you will notice in the video, start out with a straight stream through the window then open the pattern until it fills most of the window and you are getting good smoke movement. Beginning this way ensures that all of the water goes out the window and prevents unnecessary water damage. Whenever using any kind of forced ventilation, frequently check behind you to make sure that the air flow is not causing fire to flare back up between you and your path of egress.
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