Patterns of façade system design for enhanced energy performance of multistory buildings.

The paper presents a study of the effect of geometric design of equatorial-facing, double skin façade on energy performance of multi-story office buildings. The investigated parameters relate to the outer skin surface geometry and to the associated air cavity depth between the two skins of this façade system. Two main geometrical designs are investigated. A simple folded plate geometry – saw-tooth that consists of a single fold, and a more complex folded-plate units based on pyramids. The results indicate that although deviation from the basic flat façade leads generally to an increase in heating load, this is counterbalanced by a reduction in cooling load, and a considerable increase in energy generation potential from façade integrated photovoltaic systems. The position of fold and the depth of the cavity have a significant effect on thermal load and energy generation potential. Under the studied climatic conditions (Calgary, Alberta, Canada – 52°N), The total annual electricity generation potential, by the multifold configurations can exceed that of the flat façade by up to 80%. The increase in total electricity generation potential of some designed configurations is accompanied by an increase in time spread of functional electricity over extended period of time. Multifold façade configurations that combine east and west orientations can provide a peak spread of some 4–5 hours. [ABSTRACT FROM AUTHOR]