By Brent Grimm, PE, and Jane Guyer, PE, CxA
The information in this article was originally presented at CxEnergy 2021, an annual conference presented by the AABC Commissioning Group (ACG), the Energy Management Association (EMA), and the Associated Air Balance Council (AABC).
This article explores effective ways of using a monitoring-based commissioning (MBCx) program along with HVAC analytics to create and maintain a high-performing building. The content is derived from over six years of successful deployment and operation of MBCx programs in diverse industry sectors.
We will discuss why a robust program is needed to maintain building performance, and what pieces of the organizational structure need to be in place to implement a successful program. We will also discuss best practices in leveraging MBCx services with data analytics software to address not only energy efficiency, but compliance and occupant comfort.
The concept of “persistent energy efficiency” here implies a robust monitoring-based commissioning program that utilizes advanced analytics to allow a relatively small team to monitor the performance of a large number of buildings.
Why do you need MBCx and an analytics platform? Although the commissioning team for a new building tests building operation and ensures the requirements outlined in the sequence are being met, it does not guarantee long term, high efficiency performance. In fact, it is very common to see building performance degrade almost immediately. By establishing a long-term MBCx program, you can make sure that building continues to operate efficiently while maintaining occupant comfort and reducing operating costs.
When many think of monitoring-based commissioning, they first think of analytics software and reporting. While those are important elements of an MBCx program, they will be useless without a proper organizational structure and planned workflow. It’s the people and the process that turns analytics into actual savings. There are several key roles in the structure outlined here. This is not to say that this is the only way to tackle this problem, but these are the minimum number of elements recommended.
The site champion generally oversees the whole MBCx process including buy-in from management, the analytics platform selection, and managing program structure.
The site level monitor actually monitors the analytics at each of the sites. Developing a good relationship and getting buy-in from facility staff is crucial to make your project successful. They provide invaluable information and insight not gleaned from software.
The last position is the Superuser, usually an external hire for a new MBCx program. This person must be an expert with the analytics software and capable of rapidly conducting a site analysis. In order to realize the full potential of the program, this position is crucial. Their role is to continually monitor the facility, help rank priority of work, train others, and work with the analytics software to improve it to fit the needs of the facility.
Another piece is ensuring good relationships with controls vendors, chiller maintenance companies, and other service providers who will be performing the necessary work identified by the MBCx program.
Once issues are identified using the analytics platform, it is important to integrate them into the organization’s current workflow. Most facilities already have their own computerized maintenance management system (CMMS) software in place, so generally it is a matter of getting data from one piece of software to another. This can be done with custom connectors that allow data to flow between the two programs, or accomplished with manual data entry. Whichever the method, it is key to set up a path in which MBCx issues turn into work orders that are distributed to plant level mechanics and technicians.
Using Advanced Analytics
With a foundation in place, we can begin exploring benefits of advanced analytics and the fault detection and diagnostic (FDD) platform. Generally advanced data analytics pull data from the building automation system (BAS), as well as other external resources, such as meters, compressed air systems, or possibly lab specific systems. Using this data along with programmed rules, which are condition-based algorithms and custom data roll ups, it is able to convert a “swamp of data” into something quickly digested by a person or group.
One area where analytics excel is FDD to identify low hanging fruit that has quick payback. Catching rooms operating outside of their occupied hours is a great example. Without software running analytics it can be a manual process to track down these rooms. Most analytics platforms run hundreds of these rules, quickly revealing savings. In one instance, we demonstrated more advanced use of the analytics for efficiency. We used key performance indicators, which are roll-ups of select data over a period of time. One useful KPI: the sum of all condenser water pump power enabled us to catch a major efficiency issue where a bug in the BAS caused all condenser water pumps to suddenly operate at full speed. Pump power sum rose from 100 kw to 235 kw! This could have resulted in an annual penalty of ~$95,000, which would pay for about three years of MBCx. This would likely go unnoticed as long as the condenser water temperature setpoint is being met. Using KPIs like this allows us to monitor a site at a high level very quickly.
Advanced Analytics for Comfort. While efficiency is generally how the MBCx program can pay for itself, it means nothing if occupants are not comfortable! Therefore, selecting an analytics platform that can monitor all aspects of building performance is important. In Figure 1, we provide the client with information on how well spaces are meeting setpoint. In addition, we provide a table that shows the worst offenders to provide facilities staff with action items. The top five variable air volume (VAV) boxes listed are great action items to improve comfort.
Advanced Analytics for Maintenance. A great way to win over facility staff is to make their job easier, and improving tenant comfort is one way we do that. The less cold calls they have to deal with, the better! The second way we make maintenance easier is monitoring maintenance issues. Monitoring variable frequency drive (VFD) temps is an example of leveraging the power of analytics to get ahead of an issue before it becomes a disaster. Analytics are extremely valuable to help a facility shift from reactive maintenance to proactive maintenance.
Next, facility reporting helps to develop a baseline, goals, and a way to track progress towards a successful MBCx program. We also use reporting to highlight high values issues that need to be addressed so we can assign more help where needed. Reporting ensures that everybody in the organizational structure is on the same page in terms of goals and where they are at on that trajectory.
In order to maintain high-level building performance achieved through commissioning, a comprehensive, long-term program should be in place. You want key players in correct positions to ensure work orders developed from the analytics turn into energy savings. Picking an analytics platform that will fit the needs of your organization is crucial ensuring it can monitor all aspects of building performance.
Grimm is project manager, and Guyer is principal engineer at ETC Group, an energy efficiency engineering firm with more than 30 years of experience. The company is focused on providing innovative solutions to complex engineering problems and implementing leading-edge data analytics techniques.
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