Harold Brothers Blog | Harold Brothers Mechanical Contractors

Commercial BMS & Controls Optimization to Improve HVAC Performance

Written by Lisa Flynn | Jan 19, 2026 5:00:00 AM

If your commercial building constantly feels uncomfortable, your energy bills keep rising, and yet your HVAC tech insists everything is “working,” you’re not imagining things, and you’re not alone.

At Harold Brothers Mechanical Contractors, we specialize in diagnosing what’s really going on when buildings feel uncomfortable or inefficient. In many cases, the issue isn’t mechanical failure; it’s a building automation system (BMS) that has drifted out of alignment.

Our approach combines hands-on field verification with the right level of controls expertise when needed, allowing us to identify root causes accurately and avoid unnecessary changes. The result is a BMS tune-up that is intentional, well-documented, and aligned with how the building actually operates day to day.

In this article, we’ll walk you through the four areas we focus on when we suspect a controls or BMS problem: trend logs, setpoint resets, sequence fixes, and simple software updates, as well as show you how changes can help restore comfort, cut waste, and bring your building back under control.

Trend Logs: Understanding How Your BMS Actually Operates Over Time

One of the most common issues with building automation systems is that decisions are made based on what the system appears to be doing at a single moment in time. Trend logs change that by showing how the system behaves over hours, days, and weeks.

Trend logs allow us to see temperature swings, equipment run times, valve positions, damper movement, and system responses to occupancy and weather changes. This data reveals patterns that are invisible during a quick walkthrough or spot check.

At Harold Brothers, we typically address possible BMS issues by reviewing existing trends or setting up new ones on critical points. This same data becomes even more valuable when reviewed consistently during a preventative maintenance walkthrough, rather than only during reactive service visits.

In some cases, diagnosing deeper controls behavior requires specialized tools or platform-specific expertise. When needed, we collaborate with trusted specialists to validate findings and ensure sequences and logic are corrected properly, especially in complex or legacy systems.

What Trend Logs Reveal

What the Trend Shows

What It Often Means

Why It Matters

Heating and cooling active at the same time

Conflicting control logic or tight deadbands

Significant energy waste

Equipment running overnight or on weekends

Schedules overridden or misconfigured

Unnecessary runtime and wear

Supply air temperature constantly fluctuating

Poor control loop tuning

Comfort complaints and instability

Valves or dampers stuck at partial positions

Mechanical or control signal issues

Reduced system efficiency

Trend logs form the foundation of a successful tune-up because they show the truth of how the building operates when no one is watching.

Without scheduled follow-up, these same issues often return months later, which is why many facilities pair BMS improvements with a structured preventative maintenance timeline.

Setpoint Resets: Eliminating Hidden Energy Waste in Your BMS

Setpoints determine how aggressively your HVAC system heats, cools, or ventilates a space. Over time, these values are often adjusted to solve short-term comfort problems, then left in place long after conditions have changed.

In many buildings, setpoints no longer reflect actual occupancy, building usage, or equipment capabilities. The system may still maintain temperature, but it does so inefficiently, running longer and harder than necessary.

Preventative Maintenance visits includes a detailed review of key setpoints to ensure they align with how the building is currently used and how the equipment was intended to operate.

Common Setpoint Conditions Found

Setpoint Condition

Typical Cause

Resulting Problem

Cooling setpoints lower than needed

Attempt to mask airflow or zoning issues

Higher energy use

Heating setpoints raised excessively

Comfort complaints during cold weather

Simultaneous heating and cooling

Narrow temperature deadbands

Overcorrection from past issues

Equipment short cycling

No seasonal adjustment logic

Static programming

Poor performance during shoulder seasons

Resetting setpoints is often one of the fastest ways to reduce energy consumption while improving comfort. Small changes can stabilize system behavior without impacting occupants.  When those adjustments are maintained over time, they often contribute directly to improved long-term HVAC ROI through reduced runtime, lower energy use, and less equipment stress.

Sequence of Operations: Aligning Control Logic With Real-World Building Use

The sequence of operations defines how your BMS tells equipment to behave under different conditions. It controls how systems respond to occupancy changes, load variations, safety events, and startup or shutdown cycles.

Over time, sequences often become fragmented. Equipment gets replaced, spaces change function, or temporary overrides become permanent. The BMS continues to operate, but not in a coordinated or intentional way. This type of logic drift is one of the most common findings during preventative maintenance optimization, especially in buildings that have evolved over time.

As part of this process, Harold Brothers reviews how the system actually responds to real-world conditions and compares that behavior to the intended sequence.

Indicators of Sequence Issues

Observed Behavior

Likely Sequence Issue

Impact on Building

Units start in the wrong order

Staging logic no longer matches equipment

Reduced capacity and inefficiency

Poor morning warm-up or cool-down

Sequence not tuned for occupancy schedule

Comfort complaints at opening

Alarms triggering without real faults

Incorrect thresholds or logic

Alarm fatigue

Systems fail to shut down properly

Overrides or sequence conflicts

Increased wear and energy cost

Correcting sequence issues restores coordination between system components and ensures the BMS is making decisions intentionally, not reactively.

Software and Firmware Updates: When BMS Performance Issues Are Digital, Not Mechanical

In some cases, the solution to a BMS problem is not a mechanical adjustment or a sequence rewrite at all. It is a software or firmware update. Building management systems rely on control logic, communication drivers, and system firmware that can become outdated over time. Older software versions may contain bugs, communication issues, or limitations that affect how the system interprets sensor data or executes control commands. 

When appropriate, applying a targeted software update can resolve false alarms, stabilize system behavior, improve trend accuracy, and restore proper coordination between devices, often without any physical changes to the HVAC equipment itself.

How Harold Brothers Evaluates and Optimizes Commercial BMS and Controls Systems

Harold Brothers approaches BMS and controls review as a structured, methodical process rather than a series of quick adjustments. Our team leads the assessment, coordination, and implementation, drawing on a combination of in-house experience and trusted specialty partners when deeper controls expertise or manufacturer-specific insight is required.

This allows us to diagnose complex issues accurately, validate findings across disciplines, and apply the right solution without guesswork.

When Comfort and Energy Problems Start in the BMS, Not the Equipment

At the end of the day, restoring a building’s comfort and efficiency sometimes has nothing to do with failing HVAC equipment; it’s about bringing control logic, setpoints, and sequences back into sync.

You came here because your building feels inefficient or uncomfortable, even though nothing seems broken. Now you know the real culprit could be hidden within your BMS itself, and that a targeted tune-up can uncover and correct those issues at the source.

If you're ready to bring your building automation system back under control, your next step is to Request a Quote. We’ll walk your system, review the data, and help you regain the efficiency and comfort you’ve been missing.

At Harold Brothers Mechanical Contractors, we help facilities like yours eliminate silent energy waste, extend equipment life, and keep occupants comfortable, all through smarter control. Let’s bring your building back in tune.