Industrialised, Integrated, Intelligent sustainable Construction - I3con

SUSTAINABLE CONSTRUCTION HANDBOOK 2
façade can provide a comfortable indoor climate without the need for supplied air or water. By
choosing technologies that are relatively low-tech, the chance of malfunction is reduced as there are
fewer moving parts and electronics which can break down.
Recent insights into thermal comfort [1] indicate that thermal perceptions are affected by recent
thermal experiences and expectancies. In other words, people accept higher indoor temperatures in
summer when it is hot outside and lower indoor temperatures in winter when they wear a sweater
because it is cold outside. This however applies mostly to naturally ventilated buildings where people
can open or close a window; they tend to be less tolerant towards varying indoor temperatures if a
building is fully air conditioned.
The façade featured in this paper will be one of the first to be specifically designed around the new
insights into adaptive comfort perception, meaning that the strict temperature limits that are usually
applied are replaced by a more lenient approach, allowing higher indoor temperatures in summer as
long as people have a direct influence on the climate they are working in. Building services are
integrated into the façade itself at office-room scale, making the office adjacent to the façade
independent of centralised HVAC systems and the indoor environment optimally adjustable by the
user. By making use of mostly passive technologies and by extracting ventilation air directly from the
outside, the façade is able to provide a comfortable indoor climate at individual level without
consuming considerable amounts of energy. The thus created comfort is based on standards that
regard comfort in terms of a number of variables, which can be set at predefined values which are
expected to provide optimal comfort for 95% of the occupants. These standards however are based on
research into the comfort perception of people doing office work in a completely air-conditioned
environment and who have no direct control over their local climate.
The performance of the façade concept is optimised for a mild climate, similar to the climate in The
Netherlands.
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The Climate Adaptive Skin (CAS)
The main characteristics of the façade are schematically shown in Fig. 1 with the full façade on the
right and an enlargement of the ventilation unit at parapet level, containing most of the installations,
on the left. The schematic representation of an office on the right shows three identical ventilation
units of which a cross section is shown on the left. This is not necessarily the only or optimal layout;
the three separate units could be replaced by one larger unit servicing the same office area.
1. PCM stack
2. Heat exchanger
3. Fans
4. Space for electronics etc
Figure 1. Schematic representation of the Climate Adaptive Skin with shading behind glass, operable
windows and three ventilation units (right) and section of one ventilation unit (left)