The Challenge
A manufacturing facility's HVAC system ran three 12-ton air handlers continuously across 12 production and storage zones. Annual electricity consumption for cooling was ₹28 lakhs. No one questioned whether the system was being used efficiently.
What Became Visible
Energy profiling of each zone revealed that cooling demand was highly variable. Production zones needed 16–18°C during machine operation (3–5 MW heat load) but needed only 22–24°C outside operating hours. Storage zones needed only ambient cooling. Yet the HVAC system maintained 18°C across the facility year-round, even in winter when outdoor temperatures were 8–12°C. Summer months required 85% of cooling capacity; winter months required only 25%.
What Changed
Zone-based cooling scheduling implemented. HVAC delivery temperature stepped with seasonal outdoor temperature. Production zone cooling turned on 30 minutes before shift start, off 30 minutes after shift end.
How it worked: The facility maintained 12°C delivery temperature in summer (peak season) but stepped it to 16°C in winter. Production zones were temperature-controlled; storage zones were kept at ambient +2°C. Variable frequency drives (VFDs) on air handlers were set to match actual zone demand rather than running at constant speed. Winter cooling season moved to circulate mode only.
Results
annual
seasonal optimization
ambient + 2°C instead of 18°C
no production impact
HVAC systems are typically oversized for peak conditions and run continuously at those settings. Most facilities never optimize for seasonal or operational demand variations. The savings from demand-matched cooling are substantial.
Operational Reality
Most manufacturing facilities can reduce HVAC energy 25–40% through demand-based control and seasonal optimization without any impact on production or worker comfort.