C hapter 3 the Design Context
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In a building, for example, the spatial environments where we live,
work, or play are the raison d’être for the whole building. These
spatial environments have specific configurations that are geometrically defined. They also have particular environmental qualities
that support our well-being, make us comfortable, or support our
tasks. We can consider these environmental qualities in terms of
their primary thermal, lighting, and sound characteristics (Figure
3.10). For example, designers must provide an overall thermal
environment that is comfortable for inhabitants. This, in turn, is
normally accomplished via a complex set of passive material and
ventilation elements and supporting mechanical systems (e.g.,
ubiquitous heating, ventilating, and air-conditioning systems) that
function together to maintain the temperature of the room at prescribed levels. The geometric characteristics of the space, the nature
of the surrounding walls, or the kinds of glass present in fenestrations, including their material characteristics, are all contributors
to defining the thermal environment actually perceived by the
occupant. Similar observations could be made about lighting environments. There are lighting systems that provide specific lightemission capabilities, but the physical characteristics of surrounding
walls and windows contribute to the kind of luminous environment provided. The material reflectivity of wall surfaces or the
amount and kind of light that passes through windows (which
depends on the relative transparency of the window material) all
play a fundamental role in defining the kind of lighting environment that’s ultimately provided.
In these and similar situations, the primary evaluation metric is
invariably associated with some type of measure that is related to
the environmental parameter itself, such as final lighting levels at
a particular task or living area within the space, rather than to a
specific supporting component, such as emissions from a lighting
system, albeit the latter’s contribution to this measure can and
should be assessed due to its integral contribution. In a product
design situation, the performance of a thermos bottle with an
internal volume designed to keep liquids hot or cold can be evaluated vis-à-vis the degree to which it can maintain the temperature
of the liquid inside. Various kinds of mathematically based simulation tools can be used to aid in these kinds of performance predictions. Thus, in the thermos bottle, various analytical approaches or
models can be developed that take into consideration temperature
differentials between the inside and outside of the bottle and the
thermal heat-transfer properties of the bottle material. The performance would be found to obviously depend on particular material
properties but also on other parameters, such as the geometry of
60
In a building, for example, the spatial environments where we live,
work, or play are the raison d’être for the whole building. These
spatial environments have specific configurations that are geometrically defined. They also have particular environmental qualities
that support our well-being, make us comfortable, or support our
tasks. We can consider these environmental qualities in terms of
their primary thermal, lighting, and sound characteristics (Figure
3.10). For example, designers must provide an overall thermal
environment that is comfortable for inhabitants. This, in turn, is
normally accomplished via a complex set of passive material and
ventilation elements and supporting mechanical systems (e.g.,
ubiquitous heating, ventilating, and air-conditioning systems) that
function together to maintain the temperature of the room at prescribed levels. The geometric characteristics of the space, the nature
of the surrounding walls, or the kinds of glass present in fenestrations, including their material characteristics, are all contributors
to defining the thermal environment actually perceived by the
occupant. Similar observations could be made about lighting environments. There are lighting systems that provide specific lightemission capabilities, but the physical characteristics of surrounding
walls and windows contribute to the kind of luminous environment provided. The material reflectivity of wall surfaces or the
amount and kind of light that passes through windows (which
depends on the relative transparency of the window material) all
play a fundamental role in defining the kind of lighting environment that’s ultimately provided.
In these and similar situations, the primary evaluation metric is
invariably associated with some type of measure that is related to
the environmental parameter itself, such as final lighting levels at
a particular task or living area within the space, rather than to a
specific supporting component, such as emissions from a lighting
system, albeit the latter’s contribution to this measure can and
should be assessed due to its integral contribution. In a product
design situation, the performance of a thermos bottle with an
internal volume designed to keep liquids hot or cold can be evaluated vis-à-vis the degree to which it can maintain the temperature
of the liquid inside. Various kinds of mathematically based simulation tools can be used to aid in these kinds of performance predictions. Thus, in the thermos bottle, various analytical approaches or
models can be developed that take into consideration temperature
differentials between the inside and outside of the bottle and the
thermal heat-transfer properties of the bottle material. The performance would be found to obviously depend on particular material
properties but also on other parameters, such as the geometry of