Definitions

Horizontal Ventilation

Opening windows or doors on the same level as the fire to release heat and smoke.

Vertical Ventilation

Creating an opening in the roof or upper level to release heat, smoke, and fire gases vertically.

Positive Pressure Ventilation (PPV)

Using a fan to pressurize the structure and force smoke and gases out through an intentional exhaust opening.

Flow Path

The path air and fire gases take from intake to exhaust. Fire travels along flow paths; crews positioned in a flow path are at high risk of flashover.

Anti-Ventilation

Closing doors, windows, or isolation points to starve a fire of oxygen and limit fire spread.

Purpose

To ensure ventilation operations are coordinated with fire attack, improve conditions for interior crews and survivable victims, and avoid creating hazardous flow paths.

Scope

Applies to all ventilation activities at structural fires. Ventilation is never routine — every opening is a tactical decision with consequences.

Principles

• Ventilation is coordinated with water on the fire — not before.
• Every opening you make is an intake or an exhaust — know which.
• Crews do not operate between the seat of the fire and the exhaust.
• Uncoordinated ventilation feeds the fire. Always consider anti-ventilation first.

Natural / Horizontal Ventilation

1. Horizontal ventilation is the default for most residential structure fires.
2. Openings are made coordinated with the attack crew's position and water application.
3. Windows near the fire room act as exhausts; doors behind the attack crew are intakes.
4. Do not open windows ahead of the attack line unless coordinated — it creates a flow path toward unburned spaces.

Vertical Ventilation

• Used when fire conditions warrant, structural integrity supports it, and crews trained in roof operations are available.
• Never performed without a coordinated attack and a charged hoseline in position.
• Roof crews operate with a ladder planted on both sides of the opening, sound the roof continuously, and retreat at the first sign of sag or collapse.
• Conventional roof ventilation on lightweight-construction residential roofs is high risk — consider alternatives.

Positive Pressure Ventilation (PPV)

PPV is a tool, not a default. It is used only when structural conditions, exhaust position, and crew location support it.

• Use PPV only after water is on the fire — not before.
• Establish the exhaust opening before starting the fan.
• Position the fan to pressurize the intended intake with a uniform cone.
• Do not use PPV if the fire location is unknown or the exhaust path is uncertain.

Anti-Ventilation

Closing doors on a fire is ventilation. Isolating the fire from the rest of the structure is often the most effective short-term action — especially during primary search and before a line is in place.

• Closing the door to a fire room can drop conditions dramatically.
• Victims behind closed doors have significantly better survival odds.
• Consider closing doors as part of VES and search operations.

Flow Path Awareness

• Identify the intake and exhaust openings before making additional openings.
• Wind-driven fires in high-rise or upper-floor fires require wind-control tactics (door control, wind-control devices).
• Never enter a flow path without a protected position and a coordinated attack.

Responsibilities

Training Requirements

• All interior-qualified members: annual training on coordinated ventilation.
• Roof-operations-qualified members: additional hands-on training on lightweight construction recognition, cut sequences, and egress.
• Officer training on flow path analysis and PPV decision-making.

References

• NFPA 1500Standard on Fire Department Occupational Safety, Health, and Wellness Program
• UL FSRIFire Safety Research Institute — Coordinated Attack, Horizontal Ventilation, Vertical Ventilation studies
• NIOSH FFFIPPMultiple reports citing uncoordinated ventilation as a contributing LODD factor

Adapt this template

Before this template becomes your department's policy, review the following items and adjust accordingly. Anything else that does not match your operation should be updated as well.

• If your district has lightweight-construction residential stock, explicitly state policy on conventional roof ventilation.
• If your department uses electric or gas-powered PPV fans, document the specific equipment.
• Cross-reference Structural Interior, Search & Rescue, and Accountability SOGs.