Why a building can feel muggy at 72 degrees, and why the thermostat setpoint has almost nothing to do with humidity.

Why cold pipes sweat, why interior walls grow mold, and how to think about surface temperature without a psychrometric chart.

Outdoor air that a designer put there on purpose, and outdoor air that shows up whether anyone asked for it. Both count.

Why doors slam, why smoke moves through walls, and why a positively pressured building is a happier building.

What a load calculation can and cannot tell you, why two engineers get different numbers on the same building, and where the safety factors hide.