Ventilation

Last night in class we learned all about ventilation. Ventilation is used to release heat, smoke and fire build up in a room. If used properly, this can aid in search and rescue efforts and it can help crews to put out the fire quicker. Last night was a lecture class. We learned about all different types of ventilation. We learned about horizontal and vertical ventilation, hydraulic, and positive and negative pressure. The biggest things to remember with ventilation is to look for signs of potential flashover and backdrafts. If you see signs of backdraft, which include blackened windows, smoke puffs coming from the building or smoke being sucked back into the building, or smoke seeping from cracks, you need to be especially careful. If you break a window and feed the room oxygen it will cause and explosion and ignite the room. It is also important to know where you are going to ventilate. Depending on where the fire is, you will begin ventilation efforts. Every time of ventilation has a different use. Hydraulic ventilation for instance is when you use a hose line and open the nozzle to a fog stream. If you stand about two feet from a window and open the house line the water will push all of the heat, smoke and gases out of the room. It creates a sort of vacuum and will push all the contents out. The downside with this though is it uses up water, it could cause a ice hazard if it is below freezing outside, it will cause water damage to the property and it keeps firefighters in the building to preform the task. Although it does have negative effects it has proved to be very effective in ventilation. Positive and negative pressure involve fans. With negative pressure you place a fan in a doorway or window facing outside and when you turn it on it pulls all the smoke and gases out of the room. Positive pressure is placing a fan outside of the building facing the door and blowing air into the building making sure the air reaches all of the door frame. This is known as a cone of air. This will push all of the smoke and gases out from where the fire is located. If used too soon it could spread the fire so you need to be mindful of this. Another important type of ventilation is roof ventilation. This falls under verticle ventilation. You will be cutting a square in the roof above the fire to help release the smoke and gases built up inside of the room. You can use power tools or axes to accomplish this depending on what material the roof is made of. You want to always work in teams and always have a least two ways to get off of the roof in case of an emergency. Thursday night in class we will be doing hands on ventilation with a mock roof. Now that we have the lecture part under our belts, we will get to used what we learned on the fire ground at school! It is supposed to rain/snow Thursday night so it should be fun!