Editor’s note: FM Perspectives are industry op-eds. The views expressed are the authors’ and do not necessarily reflect those of Facilities Management Advisor.
In many commercial buildings, the HVAC system is not broken. The plant runs. Occupants are mostly comfortable. The building automation system (BAS) shows no obvious crisis. However, the utility bill may still be higher than it needs to be.
The remaining waste is often embedded in ordinary operating decisions: when equipment starts, how setpoints change with load, when an economizer is enabled, how fans and pumps respond to demand, and how chillers or boilers are staged. Each decision may appear small. Repeated across every hour of operation, though, these decisions define a large share of HVAC energy performance.
Many of them can be improved without replacing major equipment. But someone must own the outcome.
The Ownership Gap Begins After Turnover
A new or renovated building usually begins with a defined chain of responsibility. The design engineer writes the intended sequence of operation. The controls contractor implements it. A commissioning provider may test whether the system follows that sequence. The facility team then inherits the building.
From that point forward, responsibility becomes less precise.
Occupancy patterns change. Equipment ages. Tenants request longer operating hours. A technician disables a reset strategy while troubleshooting. An operator adjusts a setpoint to resolve a comfort complaint. A control sequence that worked during commissioning may no longer match the building’s actual load or operating priorities.
None of these changes is necessarily a mistake. Facility teams need the authority to respond to real conditions. The problem arises when temporary decisions become permanent without review, or when nobody remains responsible for asking whether the sequence is still delivering acceptable energy, comfort, and equipment performance.
The BAS may continue to execute every command correctly. It may simply be executing an operating policy that is no longer appropriate.
Facility teams do not need to write every line of controls code themselves. They do need to own the result. That means knowing what the sequence is intended to accomplish, who can change it, how exceptions are documented, and how performance is reviewed after a change.
The Opportunity Is Already Inside the BAS
Control-sequence optimization does not begin with an exotic algorithm. It begins with the decisions the existing system makes every day.
Operating schedules are one of the clearest examples. Equipment may start hours before occupancy, continue running after a building is empty, or operate through weekends and holidays because schedules were never reconciled across the BAS. Correcting those hours can reduce runtime without changing the equipment itself.
Reset strategies offer another opportunity. A fixed supply-air temperature or duct static-pressure setpoint may be appropriate under peak conditions but unnecessarily aggressive at partial load. The same applies to chilled-water, condenser-water, and hot-water setpoints. Proper resets allow the system to respond to actual demand rather than operate at a conservative design condition throughout the day.
Other opportunities are more difficult to see. Heating and cooling may occur simultaneously in different parts of the system. An economizer may be disabled or poorly sequenced. Pumps and fans may maintain more pressure than the building requires. Multiple chillers may run at inefficient loading when another staging decision would meet the same demand. A control loop may hunt around its setpoint, creating unnecessary actuator movement and unstable operation.
These are not universal prescriptions. A reset that saves energy in one building may create humidity, ventilation, or comfort problems in another. Equipment limits and local control dependencies matter. The point is not that facility teams should change settings indiscriminately. It is that existing control sequences contain operational choices worth examining.
Research suggests that the opportunity is material. Lawrence Berkeley National Laboratory’s Smart Energy Analytics Campaign studied 96 commercial organizations representing more than 5,900 buildings. Participants using energy information systems reported median whole-building savings of 4%, while participants using fault detection and diagnostic tools reported median savings of 9% after two years.
Those figures are not savings guarantees, and the researchers cautioned that other projects may have contributed to the whole-building results. More important for facility teams is what the participants were finding: scheduling problems, poor economizer operation, overventilation, simultaneous heating and cooling, ineffective temperature and pressure resets, failed sensors, and unstable control loops.
The technology helped expose the opportunity. People still had to decide what to do about it.
Low-Cost Does Not Mean Effortless
Control-sequence improvements are often described as low-cost or no-cost because they may not require new chillers, air-handling units, or other major equipment. That description can obscure the work involved.
A facility still needs usable trend data. Sensors must be credible enough to support a decision. Operators need time to investigate the system. Controls contractors may need to review or modify programming. Changes must be tested inside appropriate comfort, ventilation, safety, and equipment limits. The results must then be measured.
Without that process, a promising optimization measure can become another undocumented override.
A 2023 study of more than 60,000 pieces of commercial HVAC equipment illustrates the scale of the operating challenge. On any given day in the study data, 40% of air-handling units and 30% of air terminal units had a reported fault of some kind. Supply-air-temperature setpoint problems appeared on more than half of the air handlers at some point in the dataset.
Not every reported fault represents a large energy penalty, and fault-detection results still require interpretation. But the findings show why a facility cannot assume that a functioning BAS is an optimized BAS. Control problems can be common, persistent, and distributed across thousands of points.
Ownership Requires a Recurring Process
A workable ownership model begins with control intent. The facility team should have a current description of what the major sequences are supposed to do, including schedules, reset logic, staging rules, safety boundaries, manual overrides, and fallback behavior. That description should reflect the building that exists today, not only the original design documents.
Performance then needs a regular review. Energy data, BAS trends, comfort complaints, alarms, equipment availability, and operator overrides should be considered together. A lower energy total is not an improvement if it creates humidity problems, unstable equipment operation, or a growing queue of comfort calls.
Exceptions also need a lifecycle. When an operator changes a schedule or disables a sequence, the record should include why the change was made, who owns the follow-up, and whether the change should expire, be reversed, or become part of the approved operating strategy.
Finally, every optimization measure needs verification. The comparison does not need to become a research project, but it should account for the conditions that materially affect the result: weather, load, occupancy, operating hours, equipment state, and comfort. If the effect cannot be observed, the team cannot distinguish an improvement from a coincidental change in conditions.
This is consistent with the broader energy-management model promoted by ENERGY STAR: Make a commitment, assess performance, establish goals, create and implement an action plan, evaluate progress, and repeat. Sustained energy performance comes from a management cycle, not a one-time controls project.
Better Tools Can Make Ownership Scalable
A single facility engineer can review a few trend charts manually. A large building or portfolio can generate thousands of points every hour. At that scale, analytics become useful because they can organize data, identify recurring patterns, estimate the impact of faults, and direct limited staff attention toward the most consequential issues.
More advanced systems can go further. Fault-detection software can monitor whether equipment and sequences are behaving as expected. Supervisory optimization can evaluate changing load, weather, energy cost, and equipment constraints, then recommend or implement bounded setpoint changes through the existing BAS.
These capabilities do not remove the need for an operational owner. They make ownership more practical.
Software cannot independently determine a facility’s tolerance for comfort risk, decide whether an upcoming event justifies an exception, understand an undocumented maintenance condition, or resolve a disagreement between energy, operations, IT, and a controls contractor. Those decisions remain organizational.
The facility team must still define the approved control surface, the limits within which optimization may operate, the conditions that require fallback, and the evidence that will count as success.
The System Should Improve After Commissioning
Commissioning establishes that a building can operate as intended at a particular point in time. Ownership determines whether it continues to improve as conditions change.
For many facilities, the next meaningful energy project may already exist inside the current BAS. It may be a schedule that needs to follow actual occupancy, a reset strategy that should respond to load, an economizer sequence that needs attention, or equipment that should be staged differently.
Finding those opportunities does not require treating every building as an engineering experiment. It requires treating HVAC energy performance as an operating responsibility.
When that responsibility has a clear owner, the BAS becomes more than a collection of controllers and dashboards. It becomes an energy-management asset that can be reviewed, improved, and held accountable over time.
Chuan He is the founder of ClimaMind, a company focused on BAS-compatible HVAC optimization for commercial buildings. His work centers on supervisory control, control-sequence optimization, measurement and verification, and the operational boundaries required to improve building energy performance safely.
Chuan He is the founder of ClimaMind, a company focused on BAS-compatible HVAC optimization for commercial buildings.