Jay Gruden discusses the importance of controlling air infiltration and exfiltration in buildings to maintain comfort, health, and energy efficiency. He explains the transition from focusing on air leakage to the need for balanced ventilation, using equipment like the Xender balanced ventilation system. Jay emphasizes the benefits of balanced ventilation in equalizing temperatures and improving overall system performance. He dispels concerns about energy consumption, noting that the small energy penalty of a balanced ventilation system is far outweighed by the risks associated with a leaky building. Jay encourages builders to consider balanced ventilation for better indoor air quality.