The concept of smart buildings was birthed nearly two decades ago as a seeming child of the booming sustainability landscape. At that time, smart building efforts were focused on integrating facility systems to reduce energy use; such as utilizing occupancy sensors or card access systems to cycle on lights and pull HVAC out of setback.
Granted this was just the beginning of this dream of having truly integrated building systems that operate efficiently, proactively identify and resolve issues, and actively optimize productivity. However, after 20 years, I am still impatiently waiting to see a true smart building. (If you have a great example, please send an invite, so I can pen an excited follow-up article.)
But there are products available today that will help facility managers run smarter buildings. Here are three examples of what I believe a smart building is:
A smart building should be able to monitor equipment performance, looking not just for failure or breaches of limits, but deviation from optimum.
For example, an air handler has various sensors, dampers, coils, and fans that work collectively to satisfy space demands.
Return air temperature (RAT) is the air returning from the conditioned space, which should typically be in the mid to upper 70s degrees Fahrenheit. The supply air temperature (SAT) is the desired temperature of the air leaving the air handler needed to satisfy the conditioned space. Building code requires a minimum amount of outside air, measured in CFM (cubic feet per minute); thus, necessitating the input of unconditioned outside air, which significantly impacts a building’s efficiency and is a key parameter to monitor. The mixed air temperature (MAT) measures the resultant air temperature of combining return air with outside air; this air is then sent through the cooling coil and/or possibly heating coil (depending upon design) to create the desired SAT.
The relative differences between these various air temperatures, coupled with damper, valve, and fan percentages can tell us a lot about the function of the AHU. Algorithms can be employed to monitor these attributes and inform maintenance of a potentially failed sensor, damper, or the like.
The goal of efficiency is to utilize as little energy as possible to satisfy the load; not too little, nor too much, but just the right amount. The occupancy and use of a space are key drivers in determining those requirements. Thus, a smart building should continually evaluate demand within a space and modulate the supply to accommodate.
In the past, this has included the use of occupancy sensors and demand-control ventilation (monitoring carbon monoxide levels); however, technology has advanced well beyond these simplistic approaches to include tracking of people, devices, and thermal generation.
With the growing criticality of uptime and productivity and the continually shrinking supply of skilled labor, CBM provides one of, if not the largest, opportunity for smart operations.
A smart building should track and trend asset and building performance to monitor deviations of performance, as mentioned above. As well, it should continually analyze, learning from breakdowns and failures to direct maintenance activities, so that the right maintenance is completed at the right time; thus, mitigating unnecessary tasks, all the while maximizing the limited labor resources.
Simple examples include measuring amperage draw on a motor (along with demand) to identify anomalies such as pending belt failure, clogged filters, and misalignment.
3 Examples of a Smart Building
