Session: IMECE Undergraduate Research and Design Exposition

Paper Number: 116970

116970 - Building Emergency Indoor Stair Air Flow Analysis to Ensure Proper Positive Pressure, a Case Study 

In terms of fire safety in buildings, the implementation of pressurized exit stairs is a safety strategy that allows the evacuation of the occupants in an indoor environment. This allows a safe way and quick access for rescue forces, since pressurized environment will create a smoke-free environment, so that people can breathe and clearly see the way to exit.
The way to ensure that smoke cannot enter the stairways, in addition to structural sealing to prevent infiltration, is to raise the pressure inside the stairway enclosure.
This positive pressure environment must be always monitored considering the losses that may exist due to leakage, it must also be considered that this pressure is not excessive, thus causing stagnation of the access doors to the stairs.
The overpressure control also considers that when the doors are open, there will be a high pressure drop, depending on the number of doors that will be open at the same time. This loss must be compensated by the fan system used to create the positive pressure and if the pressure becomes excessive there will be a system of pressure dampers to release the air flow.
In this way it is then always established that there will be a minimum pressure in the system which will be linked to the dimensions of the place and the number of doors always open.
It is possible to model the system by means of Bernoulli's equations and the use of empirical constants that represent the losses of the air leakage points such as the doors and structural infiltrations, as well as the dampers that release the air flow in order to study the behavior of the fans that will inject the positive air flows, as well as the extractors that will eliminate the unsafe overpressure.
This study presents an analysis of the variables that ensure pressurized stairs using air inflow simulation. This analysis was conducted using a commercial software, i. e., SolidWORKS Flow Simulation. The behavior of the air fluid flow will be observed at different configurations of pressure drops. In addition, locations of the inlet flow and exhaust flow will be analyzed. The stairs dimensions of this case study will be based on the recommendations from the NFPA 101 standard, centered on a 10-story building. These structural characteristics are the most common in Paraguay. This work determined the leakage requirements to ensure positive pressure as well as door opening capabilities.

Presenting Author: Fabian Silguero Facultad de Ingenieria - Universidad Nacional de Asunción

Presenting Author Biography: Undergraduate Student Electromechanical Engineering Department Senior year student

Authors:

Jorge Portillo Facultad de Ingenieria - Universidad Nacional de Asunción
Fabian Silguero Facultad de Ingenieria - Universidad Nacional de Asunción
Willian Alvarez Facultad de Ingeniería - Universidad Nacional de Asunción
Willian García Facultad de Ingeniería - Universidad Nacional de Asunción
Jorge Lopez Facultad de Ingeniería - Universidad Nacional de Asunción
Jorge Kurita Facultad de Ingeniería - Universidad Nacional de Asunción