The Further Development of Double Facades in Relation to Ventilation and Light Distribution Systems

In a Cartesian graph of temperature in relation to the relative air humidity one can designate the middle region as the “human comfort zone” (see Fig. 4.40). In the region adjoining this zone the situation by moisture supply, ventilation and shade

Fig. 4.39  (48) The principle of badgir ventilation. a Wind-catchers (“badgir”) on the buildings of old Hyderabad, Pakistan. b Buildings without a courtyard. c Buildings with a courtyard. (Adapted from Behling and Behling 1996, edited)

approximates the ideal zone. According to topography or climate region one will more strongly consider one or other facet for the planning of a building.

Transparent heat insulation offers itself as a multifunctioning system. One can influence the temperature with building-ecological measures; for example, humid-ity and ventilation with air supply through earthen tunnels according to the prairie dog principle, shading according to the ”light sword principle,” which has its proto-type in the foliage system of a tree.

Architect D. Oligmüller from Bochum writes to this end: “The desire to naturally ventilate multistory structures has to this day only been partially fulfilled.”

Weak points have been as always:

1. The insufficient separation between air supply and removal 2. Overheating with continuous air spaces and thereby necessitating

3. An air supply with a high temperature, a cooled exhaust, and draft effects with ventilation in winter

4. Elaborate partition systems for the fulfillment of sound-technical, and fire pre-vention demands

For facade construction two building methods can be named that offer an excellent starting point for multifunctional systems.

1. A façade structure that allows the interstitial space to be usable (essentially a multistory greenhouse or veranda structure)

2. An updraft façade, that is closeable and then stores warmth in the buffer space, or in an opened state positively influences the balance of warmth in the building and prevents overheating in the summer

Both solutions can be combined so that their air supply through the earth is always ei-ther pre-cooled or pre-warmed according to the season. Additional pre-warming in the winter could be provided by the passive use of sun energy in form of thermohydraulic regulation that directs the air current through a buffer during heavy sun infiltration.

For their workspace the students at the Knobelsdorffschule in Berlin constructed an earthen canal that essentially improved the climatic conditions in this space with

Fig. 4.40  Comfort zone of humans in relation to temperature, humidity, and ventilation. (Adapted from Oligmüller 2001)

105 4.5 Incorporation of Wind Power

exterior pre-warming or cooling of air. As such the interior temperature is reduced for example from ca. 29 to 24 °C in the summer.

The office building for the regional administration of Bad Segeburg was to be redesigned, as the work conditions in the individual rooms were no longer tolerable due to the high amount of noise and exhaust from the directly bordering B 206 road.

Due to structural reasons the incorporation of full air conditioning was ruled out and the abandonment of the building was already being considered. Architects F. and W.

Lichtblau from Munich suggested a ventilation system through earthen passages.

Due to the bad air quality in the vicinity of the building, the passage leads from a nearby park, supported by a motor for the constant supply of consistent air flow.

The hung façade functions simultaneously as sound insulation and as space for the distribution of the air supplied by the underground passage.

American architects B. Yanda and R. Fisher can be counted as well among the pioneers of the ventilation-heat transfer system discussed here. In 1980 they pro-vided a general design for a house suitable for summer and winter utilizing this type of device.

In the 1990s Pohl Architects designed similar transfer systems for a technology center in Erfurt with functions as well for ventilation and solar gain, completed in 2002. The building became a component of the pilot research commission within the frame of an EU-supported research project “SOLARBAU-Monitor.” The bio-mimetics-inspired systems of thermally reactive building and earth masses, as well as buffer and updraft facades, were investigated based on their practicability and user friendliness. As such it is one of the earliest projects in Europe that had tested the efficacy of the complex ventilation systems according to biological prototypes with the use of earthen masses and building parts as hot or cold reservoirs. The ef-fectiveness of the measures was confirmed during a monitoring phase; at the same time the planners were able to gain important insights for later projects. A brief overview can be found in section “Complex climate systems 1: new buildings”. The building method received press from the related subject literature, particularly in climate-efficient building technology (compare Voss, Löhnert, 2006; Bürogebäude mit Zukunft, FIZ Karlsruhe. Bohne, D., 2004; Ökologische Gebäudetechnik, Kohl-hammer) (Fig. 4.41).

Biological functionality for temperature control can also provide inspiration for the highly current topic of building reuse. In section “complex climate system 2:

building reuse,” one can find a brief illustration of an older brick building, which was completely restored and reused. The team at Pohl Architects integrated the lecture hall and studios for the department of media and the university datacenter of Bauhaus University in Weimar into a former brewery building. The building masses are activated throughout the entire structure by a devised ventilation system and combined with an offset, updraft, and buffer façade. The concept functions with the intelligent use of the massive, preexisting walls in the basement level, a glass-sheathed climate buffer mounted in front of the massive, existing façade, and the ability to switch from air supply to air removal openings of the either windward or leeward oriented ventilation openings (Fig. 4.42).

Fig. 4.41  Terminal EF—Technology center in Erfurt. Pohl Architects (Fig. G. Pohl)

Fig. 4.42  Climate buffer for the Konrad Zuse Media Cen-ter in Weimar, Arch.: Pohl Architects (Fig. M. Miltzow)

4.6 Principles of Self-Organization 107

The application of biology-inspired technologies for existing structures is one of the biggest challenges of the future.