Design of an Automatic Control Algorithm for Energy-Efficient ...

8 System and functionality integration 76
passenger being equally dressed the whole year while driving the car. Another option is
a user dressed according to the ambient temperature. In summer one usually wears light
clothes, so an � �� of ���� ��� [7] is taken for temperatures above 25 ℃. In winter, pullover,
long trousers and better insulating boots are probably also worn in cars, resulting in a
higher value. Therefore, below a temperature of -5 ℃ the maximum for casual clothes
stated in [7] of ���� ��� is taken. Between these extreme values a linear interpolation is
done. The resulting function is shown in Figure 8.3.
������������������������������������
��
����
��
����
��
��� ��� �� ��� ��� ���
����������������
Figure 8.3: Assumption for clothes insulation as a function of ambient temperature.
The comfort temperature (PMV = 0) was calculated depending on the ambient
temperature for both options. The metabolism was set to ��� ���, 50% relative humidity
and no air flow was applied. The mean radiation temperature was calculated using an
estimation for the heat transfer of the car driving �� ��
�
as described in the following
section. The result in Figure 8.4 shows that the fixed clothing gives a higher comfort
temperature in winter than in summer. This setting is usually applied today [2] and is
close to the recommendation of DIN 1946-3 [11]. Most likely equal clothing has been used
for all ambient temperatures in these comfort observations. The adapted clothing factor
gives (in the relevant temperature range) the opposite - a higher comfort temperature at
a higher ambient temperature. This setting might not be accepted by everyone, but - as
the clothes are adapted to the season - it will require less energy for cooling and heating.