C haptEr 9 design Environments and systems
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By way of example, a thermal environment in a building or vehicle
is a spatial volume occupied by humans that must have certain
overall characteristics to maintain human health and comfort that
in turn define governing design criteria. Thermal environments are
served by functionally defined systems and related assemblies, such
as heating or cooling systems, but their design is also dependent
on a host of other factors, especially the geometry of the space, the
thermal properties of all surrounding enclosures, and interactions
with other systems (for example, lighting systems that produce
heat). For many products, the idea of a thermal environment
might be that of a surrounding external context that imposes particular design needs. A product might need to work in a super-cold
or super-hot environment. As with the building example, overall
performance criteria for the product again relate to the overall performance of the product with respect to the larger environmental
context. The design of specific components or systems depends on
this overall context and related criteria.
In the following sections, we look first at a series of basic environments: thermal, lighting and optical, sound, mechanical, and electromagnetic. We then examine selected enabling systems, especially
energy systems, in more detail. The design of environments and
related systems naturally is closely dependent on related material
properties (thermal, optical, mechanical, electrical, chemical) but
goes beyond them. To understand whether a lighting environment has been designed successfully, for example, it is necessary to
consider many factors: the use context (for example, library versus
church), the ambient external lighting conditions associated with
its location (sun angles, lengths of daylight), the location and type
of artificial lighting present, the overall geometry of the space, and
related types of surrounding surfaces, including the materials used
and the way they reflect, absorb, or transmit different light wavelengths. A computational method must be found for understanding how all these factors interact to create a lighting environment
that has the right illumination levels and distributions necessary for
both task performance and for human comfort. The computational
algorithms that must be used are specialized and are the province
of the design architect or engineer. This general picture also broadly
reflects the way design work proceeds in other environments. There
are invariably demands, geometrical and material considerations to
be considered, and computational algorithms needed to determine
overall performance levels. In the following discussion we very
briefly touch on these design procedures for different environments
and briefly note the kinds of computational algorithms used, but
292
By way of example, a thermal environment in a building or vehicle
is a spatial volume occupied by humans that must have certain
overall characteristics to maintain human health and comfort that
in turn define governing design criteria. Thermal environments are
served by functionally defined systems and related assemblies, such
as heating or cooling systems, but their design is also dependent
on a host of other factors, especially the geometry of the space, the
thermal properties of all surrounding enclosures, and interactions
with other systems (for example, lighting systems that produce
heat). For many products, the idea of a thermal environment
might be that of a surrounding external context that imposes particular design needs. A product might need to work in a super-cold
or super-hot environment. As with the building example, overall
performance criteria for the product again relate to the overall performance of the product with respect to the larger environmental
context. The design of specific components or systems depends on
this overall context and related criteria.
In the following sections, we look first at a series of basic environments: thermal, lighting and optical, sound, mechanical, and electromagnetic. We then examine selected enabling systems, especially
energy systems, in more detail. The design of environments and
related systems naturally is closely dependent on related material
properties (thermal, optical, mechanical, electrical, chemical) but
goes beyond them. To understand whether a lighting environment has been designed successfully, for example, it is necessary to
consider many factors: the use context (for example, library versus
church), the ambient external lighting conditions associated with
its location (sun angles, lengths of daylight), the location and type
of artificial lighting present, the overall geometry of the space, and
related types of surrounding surfaces, including the materials used
and the way they reflect, absorb, or transmit different light wavelengths. A computational method must be found for understanding how all these factors interact to create a lighting environment
that has the right illumination levels and distributions necessary for
both task performance and for human comfort. The computational
algorithms that must be used are specialized and are the province
of the design architect or engineer. This general picture also broadly
reflects the way design work proceeds in other environments. There
are invariably demands, geometrical and material considerations to
be considered, and computational algorithms needed to determine
overall performance levels. In the following discussion we very
briefly touch on these design procedures for different environments
and briefly note the kinds of computational algorithms used, but