Indoor Air Quality Basics for Housing Providers

Indoor air quality (IAQ) directly impacts occupant health, comfort, and cognitive function. For housing providers, understanding IAQ basics helps identify ventilation problems, support tenant wellbeing, and make informed decisions about building improvements.

Carbon Dioxide (CO2)

Humans exhale CO2, making it an excellent proxy for ventilation adequacy in occupied spaces. Outdoor air contains approximately 400-420 ppm CO2. Indoor levels rise based on occupancy and ventilation rates.

Interpreting CO2 Levels

• 400-600 ppm: Excellent, well-ventilated space
• 600-800 ppm: Good, typical of adequately ventilated rooms
• 800-1200 ppm: Moderate, ventilation could be improved
• 1200-1500 ppm: Poor, likely to cause stuffiness and reduced concentration
• Above 1500 ppm: Inadequate ventilation, action needed

High CO2 often correlates with high humidity, as both indicate insufficient fresh air exchange.

Volatile Organic Compounds (VOCs)

VOCs are chemicals that evaporate at room temperature. Sources include cleaning products, paints, furniture, building materials, and personal care products. Some VOCs can cause irritation or health effects at elevated levels.

Total VOC (TVOC) sensors provide a general indication of air quality but don't identify specific compounds. Persistently elevated TVOC readings may indicate:

• Poor ventilation
• Recent painting or renovation
• Off-gassing from new furniture or flooring
• Cleaning product residues

Why IAQ Matters for Housing

Poor indoor air quality has been linked to:

• Respiratory symptoms and asthma exacerbation
• Headaches, fatigue, and difficulty concentrating
• Increased risk of airborne disease transmission
• Tenant complaints and dissatisfaction

Monitoring IAQ provides objective data to support ventilation improvements and tenant guidance.