Expanded research on human shape factors for inclined surfaces

• Published in: Energy and buildings 1991, Vol.17 (4), p.283-295
• Main Authors: Kalisperis, Loukas N., Steinman, Mitchell, Summers, Luis H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Building insulation; Buildings; Buildings. Public works; Exact sciences and technology; External envelopes; Thermal comfort
• ISSN: 0378-7788
• DOI: 10.1016/0378-7788(91)90011-Q

Wherever artificial climates are created for human occupation, the aim of the design is that individuals experience thermal comfort in the environment. Among other factors thermal comfort depends on mean radiant temperature. In creating artificial climates for human occupancy, the designer must take into account the interaction of the human with the heated surfaces. Calculation of mean radiant temperature is dependent on room geometry and the position of the human within the room as expressed by the shape factors. Early work in the area provided an elaborate method for calculating person-to-enclosure radiant heat exchange for simplistic and orthogonal enclosures based only on the generation of shape factors of a person and a surface within a rectilinear enclosure. However, architecture is not limited to simple rectilinear enclosures. Geometric reduction of complex enclosures to simple rectilinear shapes is time-consuming and inaccurate, and thus is inadequate for use in the design of appropriate heating systems. This paper presents a new, expanded method based on previous work by the authors for developing shape factors of a person to a rectilinear inclined surface. This research investigated the following four cases in order to determine shape factors for inclined surfaces: (a) inclined rectangle in front of the person and above his center, and behind the person and below his center; (b) inclined rectangle in front of the person and below his center, and behind the person and above his center; (c) inclined rectangle at the side of the person and above forward of his center, and at the side of the person, behind and below his center; (d) inclined rectangle at the side of the person, below and forward of the person's center, and at the side, above, and back of the person's center. In cases where the location of the person is known, but not his orientation, a mean value of the shape factor is determined. The new design method increases the accuracy of calculation and prediction of human thermal comfort and allows designers to simulate complex enclosures, utilizing the latest design knowledge of radiant heat exchange to increase human thermal comfort. The method of solution parallels that used by Fanger to generate shape factors for horizontal and vertical surfaces.