SCS Series Manual —
P/N 15712:L 7/18/16
23
Smoke Control System Types
Concepts of Smoke Control
Definitions are given below for dedicated and non-dedicated systems, shaft and floor protection. Detailed explanations of Stairtower Pressur-
ization, Elevator Hoistway, and Zoned Smoke Control Systems follow the definitions.
Basic System Descriptions
Dedicated Smoke Control Systems.
Dedicated smoke control systems are designed for the sole purpose of controlling smoke within a
building. The equipment is not linked to building HVAC controls. This is accomplished by forming a system of air movement separate and
distinct from the building's HVAC system. Dedicated systems only operate to control the flow of smoke, and may use pressurization or air-
flow as the control method.
Non-dedicated Smoke Control Systems.
Non-dedicated smoke control systems share components with other air moving equipment. When
the smoke control mode is activated, operation of the building's air-moving equipment changes in order to accomplish the objectives of the
smoke control design. Non-dedicated systems may use pressurization or airflow as the control method.
Shaft Protection.
Shaft protection provides for smoke movement in stairtowers and elevator hoistways in either a dedicated or non-dedi-
cated system environment. It is accomplished through stairtower pressurization systems and elevator hoistway systems, described in 2.5.2
and 2.5.3.
Floor Protection.
Floor protection systems limit smoke that flows through shafts and cracks in floors or partitions in either a dedicated or
non-dedicated system environment. If this smoke is not controlled, its movement between floors can damage property and threaten life in
locations remote from the fire. Floor protection is implemented by utilizing variations of zoned smoke control, which is designed to limit this
type of smoke movement and described more fully in 2.5.3.
2.5.1 Stairtower Pressurization Systems
Stairtower pressurization systems are used to provide a tenable environment within the stairtower in the event of a building fire. A pressur-
ized stairtower must maintain a pressure difference across a closed stairtower door to limit the migration of smoke. Stairtower pressurization
can be accomplished with one of two systems - Noncompensated or Compensated.
Noncompensated System.
A Noncompensated system injects air from outside the building into the stairtower with a single-speed fan, keep-
ing the pressure in the stairtower constant with all doors closed. If one or more of the doors in the stairtower are opened, the pressure differ-
ence will decrease.
Compensated System.
A Compensated system adjusts the pressure in the stairtower based on the combination of doors that are opened and
closed, thus maintaining a constant pressure difference throughout the stairtower. This is accomplished by either modulating supply airflows
or by relieving excess pressure from the stairtower.
Smoke Control
Systems
Non-dedicated
Systems
Dedicated
System
Floor Protection
Shaft Protection
Zoned
Smoke Control
Elevator Hoistway
Systems
Stairtower
Pressurization
Systems
Non-compensated
System
Compensated
System
Elevator Evacuation
System
Smoke Movement
Prevention System
Figure 2.14 Smoke Control System Types and Implementations