3.7 Ventilation

Question 1

What is ventilation?

Answer 1

Ventilation is the planned and systemic removal of heat, smoke, and fire gases from a structure and replacing them with fresh, cooler air.

Question 2

What is vertical ventilation?

Answer 2

Vertical ventilation is the process of creating an overhead opening as high up and as close to the seat of the fire as possible.

This allows the heat, smoke, and combustion products to travel up and out of the structure—much like a chimney—following the path of least resistance (lower pressure).

Question 3

What is horizontal ventilation?

Answer 3

the process of making openings on the same level as the fire so that smoke, heat, an gases can escape horizontally from a building through openings such as doors and windows.

Question 4

What is hydraulic ventilation?

Answer 4

ventilation that relies on the movement of air caused by a fog stream that is placed 2 to 4 feet in front of an open window.

• A handline and usually a 2 person team. Usually the engine company.
• Moving water creates air currents like a mini positive pressure fan that removes air and fire byproducts from the room.
• Considered an effective and quick means of ventilating a room, esp small rooms.

Question 5

What is mechanical ventilation?

Answer 5

Uses large high-powered fans to augment natural ventilation.

There are 3 different methods:

1. negative pressure ventilation via smoke ejectors to exhaust smoke and heat.
2. positive pressure ventilation uses fans to introduce clean air into a structure and push the contaminated atmosphere out.
3. hydraulic ventilation moves air by using fog or broken-pattern fire streams to create a pressure differential behind and in front of the nozzle.