Building Orientation Analysis

2.2.3 Building orientation

Properly oriented buildings take advantage of solar radiation and prevailing wind. According to Gut and Ackerknecht (1993), the longest axis of the building should lie along the east-west direction for minimizing solar heat gain by the building envelope [12]. Wong and Li (2007) performed field measurements and computational energy simulations to examine the effectiveness of passive control methods such as building orientation in buildings of Singapore. Their results state that the best orientation for a building in Singapore with its tropical is for the long axis of the building to lie along the east-west direction.

2.2.4 External Walls

As the main goal in building design is reduction of direct heat gain by radiation

The findings by Cheung et al. (2005) also support Gut and Ackerknecht’s views on reflective and light coloured external walls [13].

Cheung et al. (2005) had conducted a study to reduce the cooling energy for high-rise apartments through an improved building envelope design. They had identified six passive thermal design strategies, namely, insulation, thermal mass, colour of external walls, glazing systems, window size and shading devices [15]. This section will consider their study on external wall; the findings from the remaining passive design strategies will be discussed gradually in the designated sections. Their study shows that annual cooling has an almost linear relationship to the solar absorption of the external surfaces.

2.2.5 Shade from existing buildings and trees

Watson and Labs (1983) recommend placing a building in such a way that it gets shaded from obtainable trees and land masses. The building can be sited to the east of such feature to reduce solar gain during afternoons when the sun is low [14]. Such effects, according to Watson (2006) can be alleviated by reducing the total smooth area on the site and shading the cemented surfaces

However, this view portrayed by Bolatturk (2008) seems to conflict with those of Gut and Ackerknecht (1993) and Yang and Hwang (1993).

They state that thermal insulation has very little efficiency in warm–humid zones because the ambient air temperature inside and outside the building is same due to the free flow of air. Yang and Hwang (1993) have added that in warm and humid regions, condensation might occur and this would demean the thermal performance of the building envelope and cause mildew problems. Moreover, Gut and Ackerknecht (1993) also note that thermal insulation has a dual nature [12].

2.2.7 Natural ventilation

Ventilation is the movement of air. According to Watson & Labs (1983), ventilation has three useful functions in the building sector. It is used to:

1. Satisfy the fresh air needs of the occupants

2. Increase the rate of evaporative and sensible heat loss from the body

3. Cool the building interior by an exchange of warm indoor air of cooler outdoor air.

Watson & Labs, 1983 explain that natural ventilation can be generated by the following two forces:

1. Temperature difference between the outdoors and the indoors.