The historic Geary Theater, built in 1909, and renowned as one of the most remarkable monuments of theater design in the world, was heavily damaged during San Francisco’s Loma Prieta earthquake in 1989.  The American Conservatory Theater (ACT) used the opportunity to renovate the theater into a modern, state-of-the-art performance arts complex.  This is one of the first theaters in the U.S. to incorporate carbon dioxide sensing for regulation of fresh air, and to convert the supply registers under each seat to serve as the return air system for accelerated warm-up.