HVAC is usually the biggest energy line item in a commercial building, and because it's complex and mostly out of sight, problems can run for years before anyone notices. Between Eric and me, we've spent over 20 years walking commercial and industrial facilities, and the same issues keep showing up. Systems heating empty spaces at 2 AM. VFDs bypassed for who knows how long. Economizer dampers stuck open for an entire cooling season. This checklist covers the 15 most common gaps we see. Use it to find your quick wins.
Controls & Scheduling
Are your HVAC schedules current?
The single most common issue we find. Buildings change — tenants leave, hours shift, floors get repurposed — but HVAC schedules stay frozen in time. We've walked buildings where the system was conditioning an empty floor because nobody updated the schedule after a tenant left years ago. Review every BMS schedule against actual occupancy. Zero-cost fix, immediate savings.
Is your holiday schedule programmed?
Related to the above, but worth calling out separately. If your BMS doesn't have a holiday calendar, your HVAC systems are running at full capacity on Christmas, Thanksgiving, and every other holiday. That's a lot of wasted energy for an empty building.
Are you using optimal start/stop?
Optimal start/stop programs the system to learn how long it takes to bring the building to setpoint and adjusts the start time accordingly. Instead of starting at 5 AM for an 8 AM occupancy (wasting 2+ hours of energy), the system might learn it only needs 45 minutes of lead time. Most modern BMS systems have this capability, but it's often not activated.
Are your setpoints appropriate?
Review heating and cooling setpoints across all zones. Occupied setpoints should typically be 70–74°F for cooling and 68–72°F for heating. Unoccupied setbacks should be at least 5–8 degrees in each direction. Are any zones set to unreasonable temperatures? Is anyone overriding setpoints and leaving them permanently adjusted?
Equipment Performance
When were your economizers last inspected?
Economizers use outdoor air for free cooling when conditions are right. But the dampers, actuators, and sensors that make them work are prone to failure. A stuck economizer damper can waste enormous amounts of energy — either bringing in too much outdoor air (overcooling and increasing heating load) or not enough (forcing mechanical cooling when free cooling is available). If your economizers haven't been inspected in the last year, do it now.
Are your VFDs actually varying speed?
We regularly find variable frequency drives that have been bypassed, locked at a fixed speed, or set to manual mode. If you have VFDs on your fans, pumps, or compressors, verify that they're actually modulating based on demand. A VFD running at 100% all the time is just an expensive motor starter.
Are constant-volume systems candidates for VFD retrofits?
If you have constant-speed fans or pumps that run continuously, they're prime candidates for VFD retrofits. The energy savings from matching motor speed to actual demand follow the affinity laws — reducing speed by 20% reduces energy consumption by roughly 50%. VFDs on air handling unit fans and chilled water pumps are among the highest-ROI HVAC measures available.
How old are your rooftop units?
If your RTUs are more than 15 years old, they're likely operating well below current efficiency standards. Modern high-efficiency RTUs with economizers, DCV, and variable-speed fans can deliver significantly lower energy consumption. Many utility programs offer strong incentives for RTU replacements, especially when upgrading from older, low-efficiency units.
Ventilation & Air Quality
Do you have demand-controlled ventilation?
DCV uses CO2 sensors to modulate outdoor air intake based on actual occupancy rather than ventilating for maximum design occupancy at all times. In spaces with variable occupancy — conference rooms, lobbies, cafeterias, event spaces — DCV can significantly reduce the energy required to condition outdoor air.
Are your air filters on a proper maintenance schedule?
Dirty filters increase the pressure drop across air handling units, making fans work harder and consume more energy. It also degrades air quality. Establish a regular filter replacement schedule and stick to it. Consider upgrading to lower-pressure-drop filter options that maintain air quality with less energy penalty.
Central Plant
Is your chilled water supply temperature reset enabled?
Many chiller plants produce chilled water at a fixed temperature (typically 42–44°F) year-round. But on mild days, the building doesn't need water that cold. Chilled water reset raises the supply temperature when full cooling capacity isn't needed, reducing chiller energy consumption. Most modern chillers can handle this, but the programming has to be set up correctly.
Is your condenser water temperature reset enabled?
Similar to chilled water reset, condenser water reset takes advantage of cooler outdoor wet-bulb temperatures to reduce condenser water temperature, which improves chiller efficiency. When outdoor conditions are favorable, this can deliver significant chiller energy savings with no impact on building comfort.
Is your chiller staging optimized?
If you have multiple chillers, the sequence in which they stage on and off matters. Running one large chiller at 90% load is typically more efficient than running two at 45% each. Your staging sequence should be optimized based on your chillers' actual part-load performance curves, not just simple load thresholds.
Building Envelope & Misc.
Is simultaneous heating and cooling happening?
This is more common than you'd think — one system heating a space while another is cooling it. Causes include miscalibrated sensors, improper dead band settings, or conflicting zone controls. If occupants are complaining about comfort in a space that seems like it should be fine, simultaneous heating and cooling might be the culprit.
Are you tracking your energy performance over time?
If you're not tracking utility consumption on a monthly basis (normalized for weather), you have no way of knowing whether your building is getting more or less efficient over time. Establish a baseline, track against it, and investigate when consumption deviates. This single practice catches more problems than any other.
What to Do With This Checklist
Walk through each item and note which ones apply to your building. Controls & Scheduling items are your quickest wins — zero or low cost with immediate savings. Equipment upgrades like VFDs and RTU replacements need capital but deliver strong ROI, especially with utility incentives factored in.
If more than 5 of these apply to your building, you've got a real project worth pursuing. Eric and I have been doing this long enough to know exactly where the biggest bang for the buck is in any given facility. Not sure where to start? That's literally what we do.
Want a Professional Assessment?
This checklist is a starting point. A professional HVAC assessment will quantify the savings for each measure and help you prioritize based on ROI. It's free, and there's no obligation.
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