Hot And Cold Running Wireless

Big buildings use a lot of wiring. For example, the Sears Tower contains enough telephone wiring to wrap around the world 1.75 times. That presents a major problem if you need to install new wiring for climate control, smoke detectors or other new technologies. That problem may have been solved by new research allowing engineers and builders to tap into an existing conduit that runs through every building: heating, ventilating and air conditioning (HVAC) ducts.

Researchers from NC State, Carnegie Mellon and Intermec Technologies Corporation have found that radio-frequency identification (RFID) systems can be used over a much wider range when used in conjunction with an HVAC system. RFID systems use centralized readers to collect data from small tags. Those tags can in turn be attached to a wide variety of electronic sensors. But, historically, ultrahigh-frequency (UHF) RFID systems have been limited by the fact that the tags need to be within 5-10 meters of a reader to work.

But in the September issue of Proceedings of the IEEE, the researchers show that UHF RFID tags can operate at distances of 30 meters or more from an RFID reader – if the signals are traveling through HVAC systems.

This could lead to wireless monitoring for conventional technologies, such as climate control, as well as the development of new monitoring technologies – such as security sensors for detecting chemical or radiological agents. And that could save a lot of money as well – since the installation of new climate control or other monitors would not entail running new wiring throughout a building.

It just goes to show that, while iPods are great, there will always be a place for radio.