Sensorial stimuli such as heat, odour, vapour, draft and air pressure result from aerial behaviour and are carried on or in the air, meaning that air flow patterns are important for architectural practice in terms than go beyond the issues of bioclimatic design, towards the construction of spatial qualities and human emotions.  The work reported in this paper is a part of a larger research agenda based on the hypothesis that invisible aerial processes are potentially a scientific basis for precise construction of architectural atmospheres. On a case study of our project proposal for Cultural Centre in Bamiyan Valley, Afghanistan  [Fig 1, Fig 2], we investigate the potential of air flow patterns in the conceptual phase of the atmospheric design process. Due to hot and arid climate, diurnal variations of temperature and local lack of infrastructure [Fig 3, 4, 5], efficient natural ventilation system has proven to be crucial for building in this location. Our proposed solution is based on a traditional Afghanistan courtyard house as a locally familiar vernacular model to further build upon. [5, 7] We developed a multiple courtyard system as an atmospheric mechanism that modulates the existing air flows to construct specific atmospheric conditions inside - each courtyard house was assigned one of the major cultural programmes. With this approach, we expect people to form unconscious attachments to each microclimate, thus stregthening their individual sense of place and local identity in the Centre. 
1. CFD SIMULATIONS I (separate elements: single enclosed space + one courtyard) [Fig 6]
This phase has provided us with series of conclusions regarding: (1) the ability of the courtyard to capture the incoming air and direct it towards the interior space, and (2) the influence of varying courtyards properties on air flow patterns and attained air flow velocities.
2. CONNECTING AIR-FLOW PATTERNS WITH SPATIAL EXPERIENCE
We listed a number of empirical observations about the connection between specific programme and possible aerial patterns (eg. exhibition spaces need more uniform air flow patterns and lower velocities, due to fragility of the artworks, whereas offices require vibrant circulation of air to maintain concentration levels high). These observations along with the conclusions from CFD simulations enabled us to construct the entire mutliple courtyard system of the Centre.
3. CFD SIMULATIONS II (entire structure) [Fig 7]
In this phase, our objectives were to obtain: (1) efficient natural ventilation everywhere, and (2) varieties of air flow patterns to gain a spectre of different atmospheric conditions inside. As a result, we detected significant amounts of stagnant air areas to be resolved in the next phase, by introducing underground air channels to switch from the initial single side ventilation, to cross ventilation system.
4. INTRODUCING UNDERGROUND AIR CHANNELS [Fig 8, 9, 10]
Our main objective was for the channels to capture the air from the incoming winds. See diagrams 6. and 7. for detailed day and night regimes.
5. CFD SIMULATIONS III (with underground air channels) [Fig 8.]
The air channels influenced the patterns of air flow to significantly change, reducing stagnant air areas, and obtaining air velocities in enclosed areas mostly bellow 0.3mps. Slight fluctuations in air velocities, close to the courtyards and air channels outlets, responded to our initial need for a variety of atmospheric conditions. However, since the variations are quite drastic, we retained the possibility of manual control of the channels outlets.
We believe that variations of courtyards configurations, underground air channels and manageable channel outlets form a highly adaptable system for future development of this project. More broadly, we have acquired invaluable knowledge on the relation between air flow patterns and courtyard house configuration, and demonstrated how the investigation into the air flow patterns can inform and influence the design process in its early phases. Additionally, we believe to have accentuated the importance of profound architectural, technological and cultural understanding of local vernacular traditions, towards the development of new, sustainable types of living. Above all, we would argue that the attained knowledge contributes to the formation of the scientific basis for comprehension and construction of architectural atmospheres.
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