Recommended Maximum Indoor CO₂ Level: 1,000 ppm

Based on maintaining CO₂ levels within 700 ppm above outdoor air levels (typically around 400 ppm).

Higher CO₂ levels indicate insufficient fresh air supply, leading to:
Decreased productivity & fatigue
Poor air quality & discomfort
Higher risks of airborne disease transmission

 CO₂ vs. CO Regulations in Parking Garages
For parking garages, ASHRAE 62.1 focuses more on CO (Carbon Monoxide) & NO₂ (Nitrogen Dioxide) exposure due to vehicle emissions:

CO Limit: 9 ppm (8-hour avg.) & 35 ppm (1-hour avg.)

NO₂ Limit: 0.053 ppm (annual avg.)

 CO sensors & demand-controlled ventilation (DCV) are required to maintain air safety in enclosed parking spaces.

 How to Maintain Healthy CO₂ Levels in Buildings?

 Demand-Controlled Ventilation (DCV) – Adjusts fresh air intake based on CO₂ levels to optimize energy use & air quality.

 Smart CO₂ Sensors – Installed in high-occupancy areas (offices, classrooms, conference rooms) to monitor air quality in real time.

 ASHRAE-Compliant Fresh Air Intake Design – Ensures proper air changes per hour (ACH) to prevent CO₂ buildup.

BMS (Building Management Systems) Integration – Automates HVAC operation for energy savings & real-time monitoring.