We all know that increasingly tight buildings require reliable and effective ventilation systems, not only for occupant comfort and safety but also for building durability. As with any mechanical system, the efficacy of ventilation can be compromised by a number of factors, including design flaws, improper installation, inadequate maintenance and operator error—some of which can only be caught through post-installation testing and ongoing monitoring. The presenters will share strategies for avoiding problems in the first place, as well as for identifying and correcting common problems that may arise after installation and commissioning.