905/909 Smoke Evacuation System

Are There Any Prerequisites For 905/909 Smoke Evacuation System?

Smoke, along with the chemicals it contains, can often be more deadly and damaging than the fire itself. This is why most of the commercial, as well as, residential structures opt for a strict 905/909 smoke evacuation system in addition to alarm and fire suppression systems.

 

In a smoke evacuation system, the smoke can either be directed or contained. This means it can be kept away from spaces where the occupants may be escaping from, such as the stairwells where people escape from, along with other sensitive zones where smoke may cause more damage.

Every smoke evacuation plan varies along with the structure, its layout, size, and requirements. Fulfilling the requirements for the 905/909 smoke evacuation system differs based on these aspects.

Mechanical Systems

Most commercial structures require some sort of smoke evacuation system that will use one or two different types of mechanical systems for proper smoke management. One system pressurizes certain areas like stairwells, preventing the smoke from entering them. The other system uses exhaust and fans to remove smoke from the designated points.

Two sets of controls are required by each type of system. One is automatic and is triggered in the event of a fire. It works more like a sprinkler system or smoke alarm; the mechanical systems start working as soon as they sense heat, particles from flame or smoke. Furthermore, each system must also have a manual override, which must be quickly accessible.

In case of a fire, the trained personnel may need to override the system; manual controls must be allowed for an override. Pressurizing some of the systems may make it difficult for the doors to open, but with manual override, the firefighters can quickly reach out to individuals who may be refuging in a pressurized area.

Having a 905/909 Smoke Evacuation System in place ensures certain points that have been labeled as sheltering points. Occupants can reach out to these points and stay there until the rescue personnel or fire department can reach them.

Zoned Smoke Control

In larger structures, each floor may require its zone for proper smoke evacuation. This is not a blanket condition but varies by occupancy. If the structure has been marked as requiring zone, each of its floors would need to be treated separately. This indicates that each floor on the building would need its own mechanical system, including smoke, exhaust baffles, and pressurized zones.

Different types of smoke curtains may be used to compartmentalize the smoke within each zone. They may be deployed across the hallways, atriums, or other sensitive areas. This is useful in creating the targeted zone essential for the mechanical systems to help clear smoke.