Page 028 - more sustainable.
Source section: Section 2 - Sustainable Thinking PDF page: 28 Guide page: 21 OCR quality: high (473 words)
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Many systems in the modern world are designed as open systems, into which materials and resources are constantly brought in from the outside, used in some way, and then released outside the system in some form of waste. For example, in most urban American communities, water, food, energy, and materials are imported into the city from sources outside the municipal boundaries. In fact, many of our materials and resources are imported from around the world. After they have been used inside the city, they are released as waste in the form of sewage, solid waste, and pollution. In nature, there are no open systems; dead and decaying matter become food for something else, and everything goes somewhere. There is no “away.” By slowing the passing of materials and resources through the system and linking elements to form new relationships and functions, we can begin to mimic nature and design closed systems, which are more sustainable. When designing buildings and communities, we must understand both the individual elements of the system and their relationships to each other as a whole. One decision may have a ripple effect. For example, improvements in the building envelope, the boundary between the exterior and interior elements ofa building, can change the requirements for the mechanical system. Using better insulation or more efficient windows might allow for a smaller heating system. At the same time, reducing air infiltration can raise concerns about the indoor air quality. Envelope design can also be used to increase daylight into the space, affecting lighting design, heating, and air-conditioning as well as improving the quality of the indoor space. But envelopes designed for increased daylighting without consideration of glare and heat gain can create uncomfortable and less productive spaces. Even the interior finishes and furnishings can change the effectiveness of natural daylighting and ventilation strategies.
Optimizing components in isolation
tends to pessimize the whole system— and hence the bottom line. You can actually make a system less efficient, simply by not properly linking up those components … If they’re not designed to work with one another, they’ll tend to work against one another. Paul Hawken, Amory Lovins, and
L. Hunter Lovins Natural Capitalism The concept of feedback loops helps explain how systems work. Feedback loops are the information flows within a system that allow that system to organize itself. For example, when a thermostat indicates that the temperature in a room is too warm, it sends a signal to turn on the air-conditioning. When the room is sufficiently cooled, the thermostat sends a signal for the air-conditioning to stop. This type of feedback loop is called a negative feedback loop because embedded in the system’s response toa change is a signal for the system to stop changing when that response is no longer needed. Negative 2 feedback loops enable a system to self-correct and stay within a particular range of function or performance. e Thus, they keep systems stable. a
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