By Rita Tatum
HVAC Article Use Policy
A critical element of the Building Internet of Things is the smart sensor. A smart sensor takes input from the physical environment and using its built-in microprocessor performs predefined functions. When smart sensors are networked across a building, they can optimize facility management.
The smart sensor microprocessor conditions signals by filtering out unwanted noise and compensating for errors before sending data to the control network. Some smart sensors also can be custom programmed to send alerts themselves, when critical limits are reached.
Today, smart sensors often are wireless. Newer versions may be self-powered, for example, via kinetic or photovoltaic technology. These options mean they can be applied virtually anywhere in the building and require virtually no routine maintenance.
Andy McMillan, president of BACnet International, believes smart sensors “allow finer grain control” of essential building data. But that’s only the first step. However, he stresses the importance of actions based on that data.
Before installing the latest and greatest smart sensors, McMillan suggests facility managers know what they are going to do with the data they get. Answering that question before deployment will help define what type and level of smart sensor is needed.
Shaun Klann, executive vice president of Intelligent Buildings, says that some smart sensors are so advanced that they now have “intelligence, software, data storage, visualization, and analysis built in the sensing package.”
For building owners who have worked to get all data, regardless of the building system, on one building management platform, smart sensors may complicate rather than simplify matters, Klann observes. That would be true if the smart sensor isn’t compatible with the existing platform.
McMillan suggests starting with areas that already have power, such as lighting. “You can install sensors at every light fixture and get a heat map of the room,” McMillan explains. “That will allow you to manage the room’s ventilation more intelligently.”
Another decision that determines smart sensor choice is whether it’s enough for the smart sensors to send that information to the lighting system program or to the larger building automation system. “Depending on the level of data analysis and the scale of your installation, you may need to send that information up to the cloud,” McMillan explains.
Where stand-alone sensing and intelligence are required, Klann sees merit in smart sensors. “Smart sensors can provide sophisticated processing and control where a platform proves cost prohibitive,” says Klann.
Klann says that domain knowledge alignment between the hardware and software is key for smart sensors. Hardware manufacturers “have the most comprehensive understanding of how that hardware or sensing element is to perform, so they are best equipped to write supporting software, analytics, and control algorithms,” Klann says.
Rita Tatum, a contributing editor for Building Operating Management, has more than 30 years of experience covering facility design and technology.