This paper proposes a novel ventilation strategy for capturing CO2 with scheduled occupancy diversity, and changes in recirculating ratio and infiltration rate. While many publications have described filters and a lamp that can efficiently capture and remove most pollutants (such as VOCs, dust, odors and viruses) to levels equivalent to those of conventional air dilution systems, no such system exists for CO2. This paper evaluates a strategy to recirculate air in the breathing zone through simulations with occupancy diversity factors from ASHRAE 90.1 2004 and Duarte et al.'s results for weekdays from 6 AM to 9 PM to evaluate a possibility of implementing a CO2 capture device. Using a lower indoor air recirculation ratio in spaces with high CO2 concentration is more effective at reducing CO2 concentration in the breathing zone. The results indicate that maximizing the air recirculation ratio by using the CO2 capturing unit could replace conventional air ventilation systems by sufficiently reducing the concentration of CO2 and supplying enough oxygen for occupational safety and health. Such a system could save air cooling or heating energy in buildings in hot or cold days or seasons, or when there are high outdoor pollution levels for a limited period of time. (C) 2015 Elsevier Ltd. All rights reserved.