Solar energy use in buildings - Solar Energy Sciences and Engineering Applications - page 615

is shown. Table 18.13.1 describes the geometric properties of the different building
types.
For single-family houses with a building standard corresponding to the con-
struction years between 1995 and 2001, the heating demand increases by 17% (to
84 kWh m − 2 a − 1 ) for a 60% site density compared to the unshaded situation (with
72 kWh m − 2 a − 1 ). Using an increased albedo of 0.7 for the surroundings instead of
0.2, the heating demand slightly reduces to 79 kWh m − 2 a − 1 for the 60% site coverage,
as shown in Figure 18.13.2.
Similar results are obtained for the multi-family houses as illustrated in Figure
18.13.3. Without any shading effect the heating consumption of a multi-family house
is 43.7 kWh m − 2 a − 1 and increases by 20% for 60% site coverage. The rather low
cooling demand of 11.4 kWh m − 2 a − 1

reduces with site density to 6.4 kWh m − 2 a − 1 ,

i.e. by 44%.
The heating consumption of the high-rise blocks with today's high insulation stan-
dards is 53 kWh m − 2 a − 1 and cooling demand is 10 kWh m − 2 a − 1 . The heating demand
is 25.5% higher for 60% site coverage. For high-rise blocks constructed between
1981 and 1985, the heating demand of 83 kWh m − 2 a − 1 rises by 16.8% for 60%

site coverage.
The heating consumption of terraced houses is highly influenced by the surface area
proportion exposed to ambient conditions. The heating consumption of corner houses

Figure 18.13.1 EnergyPlus models of building types and the urban quarter constituted of 9 generic
building blocks from each building type. The distance between the buildings varies
according to site densities. The building position numbers (1-9) are analogous for each
cluster.
Table 18.13.1 Geometric properties and U values of building types

Single Multifamily Old highrise Row Old apartment

family house house block houses (courtyard)

Geometry 10.5 x 10.5 x 3.5m 20 x 14 x 10.8m 24.4 x 24.4 x 30m 7 x 10 x 7m 10 x 10 x 13m

U values/Wm − 2 K − 1
Wall 0.5 0.3 0.88 0.5 1.45

Roof 0.3 0.3 0.97 0.3 1.3

Floor 0.22 0.22 0.85 0.22 2.6

Window 1.6 1.6 2.57 1.6 2.9