What is stairwell pressurization?

A pressurization system is intended to prevent smoke leaking passed closed doors into stairs by injecting clean air into the stair enclosure such that the pressure in the stair is greater than the adjacent fire compartment.

How is stairwell pressurization accomplished?

The idea behind the stair pressurization is that during a fire the stairway should have more pressure than the rest of the building. That way, when the doors open, the higher pressure in the stairwell pushes the smoke back onto the floor, keeping the escape route clear of smoke.

How do you calculate room pressurization?

Technical Bulletin

1. Calculation of Room Pressure (Example)
2. ACH = (V x 60) / Vol.
3. According to require condition, the room must be in positive (+ve) pressurized.
4. Date of released: 19th Oct 2009 Issued by: Raymond Vong.
5. Total pressure, Ptotal = Patm + Proom.
6. Total additional room air volume requires:

What is the reason to have a pressurized enclosed stairwell in an apartment high rise building?

Most building codes require the fire stairwells in a high-rise building to be pressurized to keep smoke out. The stairwell pressurization serves several purposes: • Inhibit migration of smoke to stairwells, areas of refuge, elevator shafts, or similar areas.

How does a stair pressurization system work in a stairwell?

In its simplest form, a stair pressurization system uses a supply fan to blow outside air into a stairwell, creating a positive pressure differential across the enclosure boundary. However, the design of these systems can depend greatly on the codes and standards used in design.

How to calculate the equation to staircase pressurization fan?

1. Air flow through internally open doors (Doors which are opened inside the building). 2. Air flow through externally open doors (Doors which are opened to outside). For how to calculate the above2 You have to see ASHRAE Applications Fire and smoke management. Q, Flow in m3/s. A, Area in m2.

When to use NFPA 92 for stairwell pressurization?

When NFPA 92 is used, the stairwell pressurization system design criteria requires specific minimum pressure differential limits based on building design factors including ceiling heights, and whether automatic sprinklers are provided.

How does stair calculator calculate stair rise and run?

The automatic calculator will design your stair stringer as close to the target height as possible, while maintaining a common step height. You can also alter the Tread Thickness [C] and Tread Depth [B] as needed. Follow the steps below to design your stair stringer: