HVAC energy optimization, from fault finding to occupancy-based control
HVAC wastes energy in three ways: faults nobody has noticed, schedules that ignore who is in the building, and setpoints that never move. Aqueduct baselines HVAC energy against weather, finds the faults, and runs equipment to real occupancy.
HVAC is the largest energy line most buildings do not measure on its own.
Where HVAC energy leaks away
- Faults that do not trip alarms
A stuck damper or a leaking valve keeps the unit running harder without stopping it.
- Schedules, not people
Units run to a fixed timetable, conditioning empty floors on holidays and after meetings end.
- Fixed outdoor air
Ventilation sized for a full building runs the same when the building is a third full.
How big the HVAC prize is
of air handlers showed a reported fault on any given day, across 60,000+ pieces of equipment.
Source: LBNL, Crowe and Granderson et al., 2023of US commercial building energy went to space heating in 2018, the largest end use.
Source: US EIAless HVAC energy when ventilation followed occupancy in a modeled 500,000 sq ft office.
Source: PNNL via ScienceDaily, 2013Three levers, applied in order
Baseline the HVAC load
Expected HVAC energy from history plus cooling and heating degree days, so a cold week is not mistaken for waste.
Fix the faults first
Fault findings in plain language: which unit, which component, what to check. Fixing faults comes before tuning.
Run to occupancy
Occupancy from sensors or a schedule drives start, stop and ventilation rules, applied where control is enabled, with owner approval.
Audit every command
Command history shows each command and whether it executed. Lockouts block new commands while one is in progress, preventing short cycling.
What to track per unit
| Metric | What it tells you | Act when |
|---|---|---|
| HVAC energy against baseline | Savings after weather is removed | Use stays above expected for a week. |
| Setpoint attainment | Whether the unit can do what it is asked | It falls into the attention band. |
| Comfort compliance | Whether savings come at the expense of occupants | Occupied zones drift out of range. |
| Runtime in unoccupied hours | Schedules that no longer match use | Units run with zones empty. |
| Sequence exceptions | Two sequences fighting each other | More than two in a period. |
sites in 21 countries run on Aqueduct.
and 9 clinics in one of India’s top hospital chains.
US airport running water intelligence on Aqueduct.
of commercial real estate under Aqueduct.
FMCG manufacturing campus.
operations run on Aqueduct.
Related
Common questions
No. Aqueduct reads from and writes to equipment over BACnet or Modbus through a field device network controller, or uses LoRaWAN relays for simple loads such as exhaust fans. The BMS can keep its sequences. See keeping your BMS.
Either dynamically from sensors or as a defined schedule per building, floor or zone. Occupancy state then triggers automation rules, such as switching a unit to unoccupied mode when a floor empties. See AI optimization.
Yes. Findings can run as recommendations your team carries out, with control switched on later for one asset at a time. Savings are measured the same way in both modes. See measurement and verification.
Faults that waste energy without tripping alarms: stuck dampers, leaking valves, economizers that never open and units running outside schedule. Each is named per component. See fault detection and diagnostics.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.