Parking garage ventilation systems fail silently, letting CO levels spike during morning rush

Enclosed parking garages rely on mechanical ventilation fans to keep carbon monoxide below 35 ppm, but these systems frequently malfunction — motors burn out, belts snap, sensors drift out of calibration — and there is no alarm or automatic shutdown that alerts drivers or attendants. During peak morning arrival when 200+ cars idle simultaneously in a confined space, CO concentrations can spike above 100 ppm within 20 minutes, causing headaches, dizziness, and impaired judgment in drivers navigating tight spaces at low speed. Garage attendants who work 8-hour shifts in these environments face chronic CO exposure that contributes to long-term cardiovascular damage. Building codes require CO monitoring but typically only mandate annual sensor calibration, and enforcement inspections happen even less frequently, so a failed ventilation fan can go undetected for weeks until someone complains about exhaust smell.