A study on the air distribution effect in the stairwell of a townhouse using single-injection air-pressurized system to prevent particulate matter

Abstract

Due to the problem of particulate matter with diameter of less than 2.5 micron in Thailand, the values exceed the standard by 3.6 times the air quality guidelines of the World Health Organization. Bringing in guidelines to prevent dust by making the interior space a dust-free area with a positive pressure room system with an air purification system. Townhouses have open spaces between the floors with connected stairways. It is a characteristic to which the principles of the compressed air system of fire escape stairs can be applied. In the general townhouse style, the differences can be clearly seen in the layout of the stairwell. When simulating the single-point air supply in the case of air supply at the top and bottom of the building using the SOLIDWORKS Flow Simulation program, it was found that the air supply point had little effect on the overall pressure condition but had an effect on the air flow direction. The air supply at the top can make the air flow more evenly than at the bottom. As for the layout of the stairwell, it affects the pressure generated. Model 1 has a straight staircase facing the front of the building, and Model 3 has a U-shaped staircase at the back of the building. There is an average differential pressure value according to the specified criteria, which is 46.85 Pa and 63.05 Pa (in the case of air supply at the top of the building) respectively. But Model 2 has an open stairwell located in the middle of the building. There will be a differential pressure value exceeding the threshold which is 111.32 Pa. However, the general townhouse model is not specifically designed to use this principle. This causes problems in the direction of the air flow that is not completely accessible and in controlling the appropriate pressure conditions.