Is your building performing properly? How do you define building performance? Many building operators may judge performance based on the quantity of hot and cold calls they receive. If the phone is not ringing, it must perform properly, right?

Early in my career, a mentor warned me that building performance cannot be judged based on customer complaints. I learned this firsthand when I had the opportunity to work with a client 12 years after I designed a system for them. In interviews for the new project, I learned there were areas of the existing building that had been uncomfortable for the entire 12 years! 

We diagnosed the issue as slot diffusers in architectural clouds configured to direct air downward onto the occupants rather than having the blades direct air horizontally to create a mixing effect at the ceiling.

The effect of a comfortable environment on worker productivity has been well-documented. Increases in productivity and lower absenteeism have a substantial influence over one of the greatest costs of a business: employee salaries. Furthermore, building mechanical/electrical/plumbing systems comprise a large capital and operating investment. We need these systems to provide occupant comfort at maximum efficiency.

My company has long advocated for diagnosing building issues and providing solutions to clients. Many years ago, my company configured its own custom wireless sensor products (pictured) that we would deploy for a week at a site. The sensors would record temperature, humidity, carbon dioxide and lighting levels. 

Through the rudimentary data collected, we would understand if the air conditioning and lighting were operated during unoccupied hours. We would then benchmark the energy costs with the Energy Star database to understand the margin between actual and the average utility costs for a building type. We understood years ago that these systems would enhance the effectiveness of systems and personnel efforts.

Over the past decade, we have partnered with a client who owns and operates many sites. We oversee its energy, water, natural gas and refuse consumption and billings. I have seen how this oversight adds value. Each month, the usage and charges are compared to year-over-year historical values. 

This methodology has identified numerous degradations in systems performance. With this client, the diagnostics have been manual and done in partnership with the onsite facilities maintenance personnel. Routine examples include increased water consumption, leading to the identification of broken irrigation lines and stuck flush valves. 

We also evaluate this client’s portfolio based on energy use per square foot and system type, identifying trends and outliers. We can see how system type affects energy use, with geothermal systems tending to be the most efficient in its portfolio. Anomalies such as unusually poor historical performance of a geothermal system are researched. In one case, the building envelope was determined to be the culprit and a capital project to increase the building insulation was identified as the solution. 

Automated Insight into a Building’s Problems

The technology landscape for automating the identification and diagnosis of opportunities is rapidly evolving. New service providers with tools that far exceed the capabilities of our in-house-developed solution are now available. We have found that one size does not fit all and can provide the right level of support to meet the client’s level of sophistication. Deploying automated fault detection and diagnosis tools is becoming the norm for many of our clients. 

Did you know that AFDD implementation is becoming a requirement of model codes? Section C403.2.3 of the 2021 International Energy Conservation Code requires new buildings with an HVAC system serving more than 100,000 square feet to implement a fault detection and diagnostics system. How authorities interpret the implementation of this code section is yet to be fully understood, but it is clear that the code is establishing the minimum functionality. 

Exceeding the minimum requirements for many customers will have a short payback period. Additionally, ASHRAE Guideline 36, High-Performance Sequences of Operation for HVAC Systems, specifies algorithms using a rules-based approach to proactively identify issues. Proactive is a key word here. New technology can identify leading indicators to address issues before the occupants and utility bills are impacted. 

Let’s break down the term automated fault detection and diagnosis into its constituent parts. First, the word automated means that the system is computer-based, using a variety of methodologies such as rule-based and model-based approaches to identify a fault. Machine learning is the new, developing frontier. As our industry is plagued by a workforce shortage and need for efficiency, using a computer to efficiently process enormous amounts of building data is a key feature. 

The next term is fault detection. Understanding what defines a fault is not trivial. My company was an early adopter at our facility. In this early implementation, the variable air volume box schedule listed a 1-inch inlet static pressure parameter. In operation, the inlet pressure was much lower, raising a flag. 

The system had to be tuned to understand that the scheduled parameter provides apples-to-apples comparison for noise generation across manufacturers and not a requirement for proper system performance. Operating at lower static pressure is desirable, provided that proper airflow is achieved. Modern AFDD systems are much better at identifying true faults and focusing on the root cause fault while de-emphasizing the cascade over other faults that may be linked to the root fault.

The last term, diagnosis, is especially powerful. I recall a conversation with a building operator who was diligently reviewing the building automation system but complained that when an issue was identified, the team did not know if they should call the mechanical engineer, the mechanical contractor, the controls contractor or send out their facilities maintenance personnel to investigate. 

AFDD systems provide insight into the problem so the right resource is applied. Furthermore, AFDD quantifies the potential impact regarding dollar value and occupant comfort so that the proper priority is set.

No Substitute for Facilities Management

For all the things an AFDD system can do, it is not a substitute for facilities personnel engagement and a genuine desire to improve operations. This reminds me of a customer’s site I visited prior to the COVID-19 pandemic. I found that maintenance was being neglected, with many air handlers lacking any filter whatsoever and outdoor air dampers shut. 

I wrote a report documenting my findings and did not hear back for six months. Then, I got a call from the client asking about the suitability of ultraviolet lights and fancy air-cleaning technologies to mitigate COVID risk. This was a corporate initiative that failed to understand the foundation of maintenance that needed to exist prior to implementing advanced solutions.

Achieving optimal building performance requires a combination of advanced technology and proactive maintenance practices. Clients who actively improve their building’s efficiency and prioritize maintenance see the greatest results. 

AFDD systems enhance the effectiveness of personnel efforts, but their success ultimately hinges on active engagement from building operators.

Justin Bowker, PE, has been part of the engineering team at TDIndustries since 2001.