When the energy managers of a retailer realised that the ventilation system of one of their stores was running at full capacity continuously, they took action to ensure the system operation aligns with actual occupancy patterns.

Thus, fan speed was lowered to 60% during unoccupied hours (00–07 and 19–00) and adjusted to 80% during occupied periods.

With this simple operational change, the retailer achieved annualised energy savings of 17 MWh and a cost reduction of 24,000 DKK.