Context and challenge
The terminal's heating and cooling plant was managed by two separate BAS, each with a cluttered interface and limited stability. Operation relied on fixed parameters: pumps ran at line frequency, staging was fixed, and cooling towers ignored wet-bulb conditions.
The retrofit had to be completed without interrupting airport operations or passenger services — and had to deliver savings that could be re-tested.
What we did
- System merge: both BAS consolidated into one platform, turning chillers, boilers and subsystems into a single organism with monitoring, smart alarms, energy management and reporting.
- Hardware retrofit: VFDs added to the primary chilled-water pumps, tertiary pumps and cooling-water pumps so equipment could be modulated rather than switched.
- Four strategies: pump frequency optimisation based on pipe characteristics, dynamic chilled-water temperature based on outdoor temperature, cooling-tower approach control based on wet-bulb temperature, and AI model learning with continuous tuning.
- Seasonal verification: separate similar-day tests in winter and shoulder season, with electricity and gas savings accounted separately.
Result
Cumulative plant EER rose from 3.0 to 4.1. Annual energy saving reached 1.17 GWh (gas converted to electricity equivalent), cutting about 1,124 tonnes of CO₂ per year and delivering a 14.54% annual saving rate. Summer electricity saving was 24.44%; winter electricity saving 10.58% with a 5.16% gas reduction.
A tertiary pump network, dual heating and cooling sources and two BAS — the most complex class of project we run. It shows that double-digit savings come from getting parameters and sequencing right, not from replacing chillers.
Similar-day comparison, by season
| Comparison | Condition | Date | Plant electricity | Boiler gas | Electricity saving | Gas saving |
|---|---|---|---|---|---|---|
| Winter similar day | Measures off | 22 Jan | 3,224 kWh | 10,823 kWh | — | — |
| Winter similar day | Measures on | 23 Jan | 2,968 kWh | 10,436 kWh | 7.6% | 3.6% |
| Shoulder similar day | Measures off | 2 Mar | 533.5 kWh | 1,483 m³ | — | — |
| Shoulder similar day | Measures on | 3 Mar | 383.3 kWh | 1,288 m³ | 28.15% | 13.15% |
Similar days were selected on comparable weather, operating hours and load, differing only in whether the measures were enabled. Saving rate R = (E0 − E1) / E0.
Comparable systems,
different results
We keep the full test record and strategy log for this project. If your plant looks similar, start with a measured audit before committing to a retrofit.