Buildings, Jan. 2014, by Jennie Morton.
http://www.buildings.com/article-details/articleid/16743/title/right-size%20your%20ventilation%20needs/viewall/true.aspx

"Can ventilation requirements and energy conservation go hand in hand? They can if you implement demand control ventilation (DCV). There’s no reason to waste energy conditioning air for people who aren’t in your building. Instead of supplying air at fixed rates, DCV automatically adjusts ventilation levels based on real-time occupancy measurements. This strategy allows you to meet code and reduce energy use without sacrificing indoor air quality."