Section III-7

Ventilation Guidelines

Purpose:  To establish tactical and strategic guidelines to be executed during structure fires when fire attacks and ventilation are essential.

Scope:  Guidelines pertain to all Three Star Fire Department personnel during fire suppression operations. 

Policy:

Following saving lives, Three Star Fire Department and our mutual aid departments have three main functions:  the tasks of ventilation, entry, and search (or “VES”) of the fireground.  In the Three Star Fire Department, these functions and roles may be handled by any of the responding apparatus as determined by the Chief or other Incident Commander.  Guidelines for ventilation operations follow, while forcible entry and search guidelines are in Sections III-8 and III-9, respectively.

There are two primary purposes for ventilation:

  1. Venting for Life:  To facilitate entry when there is known or suspected life hazard.
  1. Venting for Fire:  To make it possible for the attack crew to enter the superheated environment and extinguish the fire.

Saving life is the primary mission of the Three Star Fire Department.  Any immediate, limited ventilation is justified if it facilitates an interior search for occupants.  Ventilation for search purposes, however, can intensify the fire and could endanger other occupants of the building.  Therefore, it is vital that hose line(s) with a minimum diameter of 1 ¾” is stretched into the fire building as soon as possible to aid in ventilation, search, rescue and fire suppression.  Ventilation may be defined as the removal of hazardous and/or toxic atmosphere from a structure that has been contaminated with smoke, gases, and heat, by providing both a controlled means of escape and the controlled replacement with fresh air for the purpose of making the atmosphere safe.  It permits the advancement of hose lines rapidly which results in effectively extinguishing the fire.

The ventilation requirements are to make a building livable and to prevent further spread of the fire.  If ventilation is not first instituted at the roof prior to entry at the lower level, a back draft could result and cause total involvement and loss of the structure.  Also, if ventilation is started before charged hose lines are ready to advance, the fire could spread rapidly throughout the building.  It must be understood that ventilation will probably increase the intensity of the fire and therefore must be carefully coordinated with hose line evolutions in order to avoid increasing the severity of the fire.  There are two types of ventilation:  natural and mechanical.  As in all ventilation evolutions, personnel should pull and/or push ceilings, and remove all obstructions in order to maximize the impact of ventilation.

Ventilation will be covered extensively within the Departments training program.

The following principals of ventilation are integral to successful fire control operations:

Vertical ventilation 

This is the proven and accepted type of ventilation to be used in the initial stage of operations.  It should be performed for the following reasons:

1.  Relieves the upper portions of the building of heat, smoke, and gases.  Prevents mushrooming and minimizes early fire extension.  At the same time, it increases the survival time of unconscious or trapped victim(s).

2.  Permits more thorough search and examination above the fire.

3.   Relieves hallways and stairs of heat and smoke facilitating the escape of occupants while allowing an aggressive interior fire attack.

4.   Creates a vertical draft that channels the products of combustion, limiting horizontal spread and making control easier.

5.   Permits advancement above the original fire area to search for possible victim(s) and cut off fire extension.

Lateral (Horizontal) ventilation

1.  Permits rapid advance of hose line(s) to the immediate fire area.

2.  Reduces the danger of heat and/or flames from passing over or around the shield created from a fog pattern, since smoke and the heat are permitted to escape through these controlled openings, i.e.  windows, exterior door, etc.

3.  Make thorough search guidelines easier on upper floors as well as on the fire floor.

4.  Personnel should be aware of the effects of thermopane windows, which are commonly used today.  These windows seal the building more efficiently therefore personnel must be made aware of the increase possibilities of flashover and backdraft.  Also venting these windows with a hose stream is much more difficult.

When personnel engage in ventilation evolutions, they will do so in a manner as described above.  All personnel will also carry out their assignments with due care and diligence and will utilize forcible entry tools, i.e. axes, pike poles, crow bars, saws, halligan tools, etc..  Personnel will carry out their assignments in pairs of two and will follow orders of the Officer as to the location and type of ventilation to be conducted.  Personnel should be aware of ventilating for fire or for life.  These concepts can be explained to you by your company officers.

Under no circumstances will “freelancing” be allowed in any Three Star Fire Department operation.  All fireground operations will be conducted in accordance with the Incident Command System and the Three Star Fire Department chain of command.  Firefighters will only ventilate under the direct order of an officer.  Extreme heat and smoke conditions can develop in the fire area and the floor above the fire.  The potential for flashover and backdraft is real.  Uncontrolled horizontal ventilation can seriously jeopardize the safety of other firefighters and civilians still located in the structure.