Solar energy use in buildings - Solar Energy Sciences and Engineering Applications - page 617

situation, its heating energy demand increases by 3% for 30% site density, up to 20%
for 60% site density.
For lower-height single-family houses, the shading effect is less. Building 9 in the
centre of the site has a 13% higher demand for 60% site coverage than the unshaded
buildings.
18.14 CLIMATE EFFECT
To understand the impact of weather together with site density effects, apartment
blocks are simulated for Stuttgart/Germany, Ankara/Turkey and Hong Kong/China
weather data.
In all climates the cooling demand decreases with increasing site density and the
heating demand increases. In heating-dominated climates such as Germany, the overall
energy demand for heating and cooling thus slightly increases by 6% for the highest site
density. In Ankara/Turkey, with comparable heating demand but double the cooling
demand than in Stuttgart/Germany, there is an optimum for the total energy demand
at 30% site density. In Hong Kong, with its cooling-dominated climate, the energy
demand drops by 20% compared to the unshaded situation (see Figure 18.14.1).
Figure 18.14.1 Comparison of heating and cooling demand of apartment blocks with U values accord-
ing to the new German legislation (EnEV 2009) for different settlement densities in
Stuttgart,Ankara and Hong Kong climate.