Natural Ventilation

3.1.1        BUILDING ORIENTATION

Our country are categorized as a warm-humid climate which the characteristic of this particular climate is that they offer warm air temperature, high humidity, extensive rainfall, a substantial cloud cover, slight air movement and frequent periods of fog and heavy dew (H. Dean, 2004).

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Figure 3.1 Orientation of a building

Source: www.ecowho.com

For warm and humid climate temperature just like in Malaysia, the building should be placed preferably on southern or northern slopes, which mean that, it is supposed to facing away from the equator. The warm-humid climate zones are generally located near the equator and as a result, east and west slopes receive more radiation compared to north and south slopes. The sun rises in the east and sets in the west, so, the side of the building that is utilized for solar gain needs to be facing the south to take maximum advantage of the sun’s potential energy.

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Figure 3.1 Computer and Language Lab Orientation Plan

Based on the case study, the building facade is orientated and facing to north and south direction. A north and south direction is ideal to block solar radiation. According to MS 1525, the general rule for best orientation of buildings is to avoid facades with most openings facing to East or West.  Since the Language and Computer Laboratory is already been orientated to north and south directions, this will avoids from absorbing too much of the sun’s heat energy into the building. In hot humid climates and hot dry climates with no winter heating requirements, the aim is to exclude direct sun by using trees and adjoining buildings shown in Photo 3.1. However, the front elevation facing southern equator while the rear elevation facing east and west equator. This will lead to maximum solar heat gain and due to this, the room will receive high solar during the day.

The adjoining building of the Language and Computer Laboratory blocks the sun from directly enter the building, it helps to reduce heat gain since the building is facing away from the sun's path.

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Photo 3.1 Adjoining building of Language and Computer Lab

3.1.2        NATURAL VENTILATION

Natural ventilation is the process of supplying and removing air by means of purpose to provide opening such as operable windows, ventilator and shaft, and the natural forces of wind and temperature that has difference pressures. Some of the important things of ventilation especially for human comfort are to supply fresh air in order to gain an adequate supply of oxygen, to remove any contaminants in air and to provide thermal environment as it will assist in the maintenance of heat balance of the body in order to prevent discomfort. Natural ventilation takes place mostly through windows, so it is crucial for designers to take concern on the locations, numbers, size and orientation of the building and design detail of the windows.

Based on the case study, the building has a numbered of openings including windows but most of the windows available in the Language and Computer Laboratory are a fixed type windows and the windows are covered with a tinted shade. This tinted shade is important to the windows, it is used to prevent heat and direct sunlight from entering the room. However, since the building mostly uses a fixed type window, this will make it difficult for natural ventilation to occurs in the building.

The room that has been chose to observe is at the ground floor, which is MBK 002. Both of these rooms contain numbered of windows but only a few of them are operable which is at the top side of the window as shown in Photo 3.1 however, a small amount of cross-ventilation could occur in both of the rooms since there’s an operable window facing towards each other.  

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Figure 3.1 Ground floor plan of Language and Computer Laboratory

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Photo3.1 Window type at room MBK 003