This brief is all about how visualization tools can take a retro-commissioning program to the next level. As mentioned in the last Program Brief, building automation systems produce heaps of data. Most of it is simply written over in a matter of days or weeks. Rather than losing that data, new data tools allow retro-commissioning providers to collect huge amounts of data to be easily harvested for analysis. But (quickly!) making sense of that data is another story. This is where visualization techniques step in.
Visualizations are not just pretty pictures. Visualizations provide actionable insights or quickly answer questions about how a particular system operates.
Imagine yourself as a facility manager. You have a piece of equipment that you think is always turning off at night. That’s what your controls say, right there on the computer screen. Then you see the AHU Hourly Airflow chart of actual data of the air flow from a variable speed fan in your retro-commissioning report.
The supply fan CFM (cubic foot per minute) is a measure of how much air is flowing through the unit at that time. Before seeing this chart, you may have felt some doubt or hesitancy upon hearing the unit doesn’t shut down (justifiably so if your controls screen says the unit is scheduled). After seeing the data, it’s pretty clear that no matter the time or the day, that unit isn’t shutting down or even varying its flow. Or the airflow monitor is broken. Either way, something needs to be fixed.
But it’s not always about proving something to someone. Retro-commissioning is about understanding the ins and outs of how a current building is performing, and then using that understanding to improve it. Especially in more modern facilities with complex equipment, data visualization can help a provider quickly come to grips with how that system is operating. Take for instance figure 2 (Energy Recovery System Operation).
Without data visualization, understanding how this unit alternates modes may require a PHD on the controls logic. With data visualization, patterns leap out from the data and figuratively slap the viewer across the face. Visualization allows engineers to quickly understand how equipment is operating to 1) confidently decide whether to move on to the next task rather than wasting time digging through the volumes of collected data, 2) avoid implementing measures that don’t work or cause problems, and 3) minimizing the risk of passing over potential measures because they weren’t well understood. And because visualizations are typically generated using code, migrating it to the next piece of equipment usually takes only seconds, ideal for buildings with many similar pieces of equipment (or Utility programs that can share visualizations from one project to the next).
In the end, data visualization can help reduce costs, identify more energy savings, and secure owner buy in on retro-commissioning projects. All of which are critical aspects of any energy efficiency program.