*3.2.1 Shading devices*

*Zero and Net Zero Energy*

Geometrical shape

**Table 1.**

Walls, floor Height-to-width or to area ratio

Windows Location, window/

Orientation North–south or

*Courtyard design variables (author).*

color

walls [27]

wall ratio

west–east

Material, thickness,

Outside stepped or tilted [27]

Inside stepped or tilted

Zamani et al. [9] studied how to improve the thermal performance of the courtyard by studying various design factors such as proportion, orientation, geometry, opening characteristics, and material. In addition they studied more variables like shading devices, vegetation, and water pools and their impact on heat mitigation. Sadafi et al. [10] explained how using internal courtyards in terraced houses in tropical regions improves the natural ventilation and thermal comfort. Meir et al. [11] investigated how two semi-enclosed attached courtyards will affect the microclimate in the enclosed courtyards and the attached built volume. Muhaisen [12] showed that courtyards' shading performance depends on the form's properties, location, latitude, and available climatic conditions. Berkovic et al. [13] studied the effect of courtyard design variables, like orientation, horizontal shadings, galleries, and trees, on the thermal comfort of the courtyard's surrounding functions. Muhaisen and Gadi [14] investigated how courtyards' proportions and surface colors considerably influence thermal comfort of the surrounding spaces. Al-dawoud and Clark [15] investigated how different design parameters of the courtyard affect the thermal comfort in spaces surrounding the courtyard. They approved that courtyards are more energy efficient

**Elements Variables How to maximize storing action in hot climate**

High H/W ratio [11]

shaded areas Landscape Greenery type, height Define the patterns of shade or expose shaded area on floor and walls

the courtyard

absorbance, and reflection

optimize shading and ventilation

High thermal mass stores low temperature, heat

Increases the shaded areas and improves courtyard's thermal performance and storing action in hot regions

Increases surface exposure to sun and therefore reduces the

As the openings allow air to be drawn from the rooms to

A balance based on prevailing winds and solar angles, to

in hot-dry and hot-humid climates in comparison to cold climates.

relations with the outdoor and site design.

The design of courtyard with other devices and elements should be made to enhance storing effect and ventilation process, which include the opening, thermal mass, landscape, and building form. Elements that could be integrated should enhance storing action of the courtyard like thermal mass, wall geometry, and landscape. Moreover, to enhance heat exchange between the courtyard and surrounding spaces, other devices could be integrated with the courtyards like wind tower, solar chimney, basement, and opening design and bearing in mind the design requirements in early stages of design process. Therefore, design decisions will have direct impacts on the building's form, orientation, area, zoning, function distribution, and

Avoidance, as a passive cooling action, refers to all the methods used to prevent

and reduce the amounts of heat gains from direct solar radiation or wind. The key methods of avoidance include different shading devices, building's form, and

**40**

**3.2 Avoidance**

Cho et al. [16] presented an integrated approach for exterior shading device design analysis that included cooling energy performance and economic feasibility in high-rise residential buildings. The research investigated the effect of 48 exterior shading devices on the sunshading/daylighting performance. Palmero-Marrero and OLiveira [17] studied the effect of static louver shading devices on east, west, and south facades for various locations on the energy demands during cooling and heating seasons. The research concluded that the shading device reduced the total annual energy demands in buildings of countries with long dominant cooling seasons and high ambient temperatures and solar radiation.

Datta [18] studied the effect of external fixed horizontal louvers on the thermal performance in the buildings. The study was aimed for reducing the overall energy requirements for the entire year by maximizing the shading device system to reduce solar gains during summer and allow them during winter. The study used TRNSYS as a simulation to maximize the efficiency of the device, and different slat lengths and tilt angles were tested in four Italian cities. Yao [19] evaluated the effect of shading control strategies on the daylighting, visual comfort, and energy performance in buildings.

Designing buildings with the passive approach requires integration of many factors together in the process, such as orientation, shading devices, and building form in order to reduce energy consumption in the building as a whole as seen in **Table 2**. Largely glazed facades and large windows have been increasingly used in new buildings, allowing access to daylight, solar heat gains, and external views. The increase in glazed surfaces requires significant attention in building design, regarding the impact they have on cooling, heating, and lighting loads demands. Therefore, it is important to provide these buildings with a proper shading design that would provide interior spaces with thermal comfort by controlling solar heat gains and reducing glare while maintaining the initial purpose of large glazed surfaces to provide external views and sufficient daylighting.

Many researches were conducted to study the performance of shading devices in order to optimize their performance, save energy, and achieve the maximum thermal comfort. Datta [18] used computer simulation to study variables related to horizontal shading devices and their effect on the thermal performance in buildings in Italy. The study showed that shading devices could help save energy and


**Table 2.** *Shading device variables (author).* improve the thermal performance of the buildings. Palmero-Marrero and OLiveira [17] proved that shading devices could improve thermal performance of buildings and save energy in many cities in different latitudes and climatic conditions.
