Dive summary:

• If contractors had to bet on one item that will be in the specs for new construction and retrofits in the future, they should put their money on a sensor that can control air flow in building zones by counting how many people are present.
• The Department of Energy's Pacific Northwest National Laboratory ran tests with the devices, which are expensive and not yet widely available but are expected to come down in price, and found that they could shave 18% off HVAC expenses by not filling spaces with heated or cooled air when almost no one was there.
• One issue, the researchers noted, is that building codes may have to be updated because they mandate certain air exchange rates without consideration of what volume is necessary for health and comfort at different occupancies.

From the article:

"An 18-percent boost in building energy efficiency by modifying a single factor is very, very good," said team leader Michael Brambley. "The savings were much greater than we expected."  ...