With air conditioning being available for a little more than 100 years now, the ability to provide both heating and cooling to a space has led to our migration to a life with 90 percent of our time being spent indoors. While there have been many improvements to HVAC (heating, ventilation and air conditioning) over recent years, the most overlooked strategy for improvement is what the industry calls DCV (demand control ventilation).
When the first version of the ASHRAE ventilation guidelines (62.1) were published in 1973, this was the first time that controls were really looked at to improve indoor air quality in buildings, with CO2 being used as a means to determine the number of occupants in a space. People breathe out CO2 at a constant rate so using CO2 to determine how much heating, cooling or ventilation to provide to a space allows for both better indoor air quality but also great energy efficiency.