CASE12 · Manufacturing · Cooling, HVAC and compressed air
Finding utility savings through integrated cooling, HVAC and compressed-air data
Seasonal and one-minute records connect COP, staging, AHU filter pressure and compressor unloading. The report estimates utility savings while keeping production-equipment electricity outside the improvement boundary.
01 · CASE ANALYSIS
Operating challenge
The cooling system ran an average of about 2.1 chillers against 1.2 calculated as required. AHU filter pressure and outdoor-air damper settings varied significantly between equipment and seasons.
Compressor demand, discharge pressure and loading/unloading also varied. One-minute analysis exposed short loss peaks that monthly averages concealed.
02 · CASE ANALYSIS
Data and performance diagnosis
Chiller load, power, COP/UPI, water temperatures/flows, pump/tower staging, bypass valves and header pressure were analyzed alongside AHU filter ΔP, outdoor-air dampers and return temperature/humidity.
Reported cooling-system UPI averaged about 0.84 kWh/RT, COP 4.20 and load 55%. Some filter pressures reached 19–22 mmAQ versus 12–13 mmAQ elsewhere. The additional CDA analysis reported UPI around 0.126 kWh/m³, load 81%, mean loss 3.1% and a maximum instantaneous loss of 31.7%.
| Boundary | Baseline electricity |
|---|---|
| AHUs | 1,284,297 kWh |
| Cooling system | 4,575,524 kWh |
| Compressed air | 3,313,220 kWh |
| Other utilities | 1,230,530 kWh |
| Utilities excluding process | 10,403,571 kWh |
| Whole site including process | 31,370,955 kWh |
03 · CASE ANALYSIS
Proposed improvement portfolio
The main opportunity was cooling-system optimization: required-unit operation, efficient-unit priority and coordinated pumps/towers. Smaller opportunities concerned AHU filters and outdoor-air controls, compressor combinations/pressure and other utilities.
The portfolio estimates 444,832 kWh/year, approximately KRW 49,821,132/year. This represents 4.3% of utility electricity or 1.4% of the whole-site electricity when process equipment is included.
04 · CASE ANALYSIS
Measurement and verification
These are 2018-baseline potential estimates. Build an adjusted baseline using cooling load, production, weather, compressed-air demand and operating hours before comparing implementation results.
A 31.7% instantaneous system-loss peak is a diagnostic observation, not a site annual savings rate.
| Boundary | Potential | Rate |
|---|---|---|
| AHUs | 12,843 kWh/year | 1.0% |
| Cooling system | 320,287 kWh/year | 7.0% |
| Compressed air | 99,397 kWh/year | 3.0% |
| Other utilities | 12,305 kWh/year | 1.0% |
| Utility total | 444,832 kWh/year | 4.3% |
| Whole-site equivalent | 444,832 kWh/year | 1.4% |
05 · CASE ANALYSIS
Engineering lesson
Use the same numerator with the correct denominator. The utility-only 4.3% and whole-site 1.4% describe the same estimated saving under different accounting boundaries.
APPLY TO YOUR SITE
Connect your operating data to an actionable energy strategy.
Discuss the measurement boundary, data quality, operating constraints and verification approach for your facility.
Discuss your project All English cases