Houston, We have a Moisture Problem

Apollo 13 wasn’t caused by incompetence, it was a chain of individually reasonable decisions that combined catastrophically. That’s the moisture story in buildings. The engineer who raised the chilled water setpoint to save energy wasn’t wrong in isolation. The occupant who opened the windows using natural ventilation wasn’t wrong in isolation. How can “the dry building mission” be kept on track? Excess indoor humidity is the problem. So, budget and design for (and then keep) the indoor air dew point below 15°C at all times, including unoccupied hours.