Originally designed to support an occupancy level of 850 people, the 190,000 ft² corporate headquarters at ArcBest has grown to now have 1,085 people plus visitors. Ten percent of the people work at night, requiring 24/7 conditioning of air. The increase in occupancy drove a need to introduce more outside air to maintain air quality per ASHRAE 62.1: VRP (Ventilation Rate Procedure) requirements. All of this outside air had to be conditioned, increasing electrical energy costs. In addition, the extra outside air caused draftiness on cold winter days, and during the summer the extra outside air flow through the air handlers resulted in some parts of the building getting too cool - generating lots of complaints to facilities management. ASHRAE 62.1 IAQP (Indoor Air Quality Procedure) was implemented, delivering improved indoor air quality, much improved comfort as all complaints stopped, and energy savings.