The contribution of bioclimatic architecture in the improvement of outdoor urban spaces - Solar Energy Sciences and Engineering Applications - page 635

Figure 19.3.3 The assessment of bioclimatic technologies for outdoor spaces.

simulations, architectural and engineering measures have been proposed to improve
climatic conditions in the area. Additional simulations have been carried out to evalu-
ate the impact and the potential of the proposed measures on the climatic conditions in
the area. Based on the results of the simulations, the overall design has been optimized
(see Figure 19.3.3).
Advanced computerized fluid dynamic tools can be used to simulate the micro-
climatic conditions of an urban area. This permits validation of the accuracy of the
simulation code used. Simulations can be performed to evaluate microclimatic condi-
tions during peak temperature periods in summer. Based on the results obtained from
the audit and the simulations, architectural and engineering measures can be proposed
for improvement of climatic conditions in urban areas. Additional simulations can
be carried out to evaluate the impact and the potential of proposed measures on the
climatic conditions. Based on the results of simulations, the overall design of urban
areas can be optimized (see Figure 19.3.3).
Some examples are included below and are tabulated in Table 19.3.2.

• Ng et al. (2011, 2012) studied the thermal effects of greening in improving the

urban microclimate in the city of Hong Kong. It was emphasized that the cooling
potential of the different greening strategies is related to building morphology.
As a general rule of thumb, a reduction of outdoor temperature equal to 1 K is
possible when tree coverage is larger than one-third of the total land area for areas
where the building coverage ratio is almost 44%, which is the average value in
Hong Kong. The greening effect on the thermal environment is considerable when
greening of building façades rather than on rooftops is done.

• A rehabilitation of Albania's capital city of Tirana's historic centre was performed

by Fintikakis, et al. (2011). The area under study has hot and dry summer climatic
conditions and an analysis of the outdoor environment showed that there are
up to 3 ◦ C local temperature differences due to different local thermal balance.
Moreover, ambient temperatures in well-shaded areas may be 1.4-2.0 ◦ C lower
that in neighbouring zones of similar configuration. The area was modelled using
Computational Fluid Dynamics (CFD) modelling and a series of technologies were
proposed for the improvement of the outdoor conditions, including:

◦ Extended use of shading and solar control to reduce the surface temperature

of the materials and the corresponding heat convection;