STAIRWELL PRESSURIZATION SYSTEM
COMPONENTS
A pressurization system consists of three main components:
- Supply Air (where air is injected into the area that is to be protected);
- Pressure Relief (to avoid over-pressure when doors are closed), and;
- Air Release (air and smoke is released from the adjoining fire area). Combining these elements creates a positive pressure difference that prevents lobbies and staircases from filling up with smoke.
A pressurization system for smoke and fire ventilation should meet the recommendations of:
- NFPA 101: Life Safety Code
- NFPA 92: Standard for Smoke Control Systems
- Other international codes of practice, and;
- Local authority regulations.
SYSTEM REQUIREMENTS:
- Maintaining a pressure difference for a closed door condition.
- Maintaining a velocity for an open door condition.
- Right balance is required in a pressurization system. Insufficient pressure difference across a closed door will allow the passage of smoke into the protected space. Excess pressure will impede door opening and hence escape.
DESIGN METHODOLOGY:
- Assess the usage and layout of the building, the area to be pressurized and the class of system required.
- Assess the leakage paths (through doors, lifts, vents).
- Calculate the required volume flow rates.
- Calculate the area of pressure relief dampers.
- Calculate the area of air release ventilation.
WHAT WE OFFER
1. STAIR CASE PRESSURIZATION
- The stairwell pressurization serves several purpose:
- Inhibit migration of smoke to stairwells, areas of refuge, elevator shafts, or similar areas.
- Maintain a tenable environment in areas of refuge and means of egress during the time required for evacuation.
- Facilitate the fire and rescue operation by improving visibility in the building for the firefighting crew.
2. LIFT-SHAFT/LIFT-WELL PRESSURIZATION
Elevator shaft pressurization is required to protect the shafts from ingress of smoke. Thereby, it restricts smoke spread to other floors connected to the shaft.
SMOKE EXTRACTION SYSTEM
INTRODUCTION
Smoke extraction systems are designed complying with the following codes: NFPA 92, NFPA 204, BS 7346 Part 4, other international codes of practice, and local authority regulations.
CORRIDOR SMOKE EXTRACTION SYSTEM
Corridors are provided with a mechanical smoke purge system. The intent of a smoke purge system is for the clearance/removal of smoke during evacuation and firefighting operations. Make up air shall be adequately supplemented based on the total smoke extract capacity.
STATIC SMOKE EXTRACTION SYSTEM
A smoke extraction system utilizing smoke reservoirs; localized ducting; and permanent openings and / or automatic opening of windows, panels or external louvers actuated by smoke detectors; to remove, on the principles of natural ventilation.
DYNAMIC SMOKE EXTRACTION SYSTEM
A mechanical ventilating system capable of removing smoke and products of combustion from a designated fire compartment, and also supplying fresh air in such a manner as to maintain a specified smoke free zone below the smoke layer. detectors; to remove, on the principles of natural ventilation.
