Ventilation is a part of structural firefighting tactics, and involves the expulsion of heat and smoke from a fire building, permitting the firefighters to more easily and safely find trapped individuals and attack the fire. If a large fire is not properly ventilated, not only will it be much harder to fight, but it could also build up enough poorly burned smoke to create a smoke explosion, or enough heat to create a flashover. Contrarily, poorly placed or timed ventilation may increase the fire's air supply, causing it to grow and spread rapidly. The flashover may cause the temperature inside the building to peak at over 1000 °C (1850 °F).
Types of ventilation
In general, there are two types of ventilation; vertical and horizontal. Their names refer to the general locations of the intended exit points of the heat and smoke to be ventilated. Vertical ventilation takes place through holes cut in the roof, typically by truck companies during the early stages of a fire in a process known collectively as roof operations, while horizontal ventilation usually takes place through doors and windows. The goal of each is to clear heat and smoke to increase chances of survival for trapped occupants, and/or so that water lines can be advanced into the structure, to more effectively battle the flames. While their goals are similar, their applications are different, but still both require good timing and coordination so that increased air flow through a structure doesn't contribute to fire spread.
Ventilation is the intentional introduction of outside air into a space. Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used for purposes of thermal comfort or dehumidification when the introduction of outside air will help to achieve desired indoor psychrometric conditions.
The intentional introduction of outside air can be categorized as either mechanical ventilation, or natural ventilation. Mechanical ventilation uses fans to drive the flow of outside air into a building. This may be accomplished by pressurization (in the case of positively pressurized buildings), or by depressurization (in the case of exhaust ventilation systems). Many mechanically ventilated buildings use a combination of both, with the ventilation being integrated into the HVAC system. Natural ventilation is the intentional passive flow of outside air into a building through planned openings (such as louvers, doors, and windows). Natural ventilation does not require mechanical systems to move outside air, it relies entirely on passive physical phenomena, such as wind pressure, or the stack effect. Mixed mode ventilation systems use both mechanical and natural processes. The mechanical and natural components may be used in conjunction with each other or separately at different times of day or season of the year. Since the natural component can be affected by unpredictable environmental conditions it may not always provide an appropriate amount of ventilation. In this case, mechanical systems may be used to supplement or to regulate the naturally driven flow.
The incident occurred around 10 am today when the young puppies, both one-month-old and female, were discovered on top of a ventilation duct on the third-floor platform.
JAMESTOWN — Lincoln Elementary School students raised funds for a family who lost their home to a fire earlier this year ... ADVERTISEMENT ... Firefighters found heavy smoke and fire in the crawl space of the house and extinguished and ventilated the smoke ... .
FRANKLIN PARK, Pa. — The HighlandVolunteer Fire Department broke its record for most calls in a year ... The firefighters ventilated a second floor and worked at the scene for about an hour ... WatchWPXI NOW ... ....
Firefighters called a third alarm after arriving about 9 a.m ...Eventually, firefighters cut a hole in the roof of the warehouse to ventilate the heavy smoke, while others opened doors and windows to clear visibility ... No damage estimate was provided ... ....
The fire is not considered suspicious ... "The machine is a block and a half long ... The fire also got into the ventilation system, but the machinery took the "brunt of the damage," he said ... Firefighters addressed the other smaller fires, he said ... ....
Ladder 6 began searching the residence for any potentially trapped parties, and Ladder 8 began coordinating ventilation tactics to reduce smoke and heat buildup and provide a safer environment for firefighters and potentially trapped occupants ... .
Firefighters ventilate building to allow residents to return. The fire was contained to just the single first-floor unit, but firefighters worked to ventilate the building to allow residents back in, which they were able to do later Saturday morning.
Sandwich firefighters entered the building and supplied the sprinkler system with more water ... It took firefighters 30 minutes to put out the fire and crews remained for another hour ventilating the multiple units in the building.
Firefighters wearing gasmasks were pictured exiting the lawyers' offices after leaving time for the carbon monoxide to ventilate ... Firefighters wearing gasmasks were pictured exiting the building after leaving time for the carbon monoxide to ventilate.
Firefighters had to tear down entire walls in the building to ventilate the roof, and they were still conducting a second round of searches and sifting through debris late Monday night ... A firefighter ...
Firefighters also ventilated the roof to manage the smoke and heat while CenterPoint Energy was called to assist at the scene ... However, quick action by the 53 firefighters who responded saved an estimated $185,400 worth of property.
MUMBAI ... CR fifth rail corridor on fast track, will be complete in a year ... They will also have features like public refuge areas, a tunnel control system (SCADA), lighting, firefighting and ventilation mechanisms ... Catch every big hit,. See more ... ....
By 9.15 a.m., the block was surrounded by trucks with ladders leading to multiple floors, firefighters providing ventilation and a small group of residents milling around outside trying to determine if there was really a fire.
The Danville News
19 Dec 2024
The Danville News
19 Dec 2024