Wireless Sensors and Controls Make the Organic Building

The concept of the intelligent building, able to make informed, autonomous decisions about energy consumption based upon real-world variables such as occupancy and the external environment, has suffered from the cost and complexity required to deploy sufficient sensors and actuators to provide fine-grained control and sensing. While there have been a plurality of proprietary wireless systems developed over the past decade or so for application to this problem, these systems have suffered from robustness and reliability issues, as well as the inability to scale well in cost and network complexity. In 2003, the IEEE 802.15.4 standard was ratified, and almost immediately silicon manufacturers began producing compliant single-chip radios. The ZigBee Alliance, formed in 2002 and dedicated to using the IEEE standard as its baseline wireless communications standard, has developed a specification that allows the rapid creation of mesh networks that are also self-healing. With energy-saving features designed into the basic IEEE standard, and other possibilities applied by the applications developer, IEEE 802.15.4 radios have the potential to be the cost-effective communications backbone for simple sensory mesh networks that can effectively harvest data with relatively low latency, high accuracy, and the ability to survive for a very long time on small primary batteries or energy-scavenging mechanisms like solar, vibrational, or thermal power. This paper focuses on the commercial building control environment and its needs for substantial energy consumption reduction now and in the future by means of more tightly linking the raw energy consumption with the human presence or activity within the building. A practical example of green building construction on a small scale, with some level of linking between the disparate systems, is given