Air quality
Indoor Air Quality Basics for Your HVAC System
Filters, ventilation and humidity — what actually helps and what to ask a contractor.
Last reviewed · 5 min read
Three main strategies
EPA describes three basic strategies to improve indoor air: source control (removing or reducing pollution sources), ventilation (bringing in outdoor air), and air cleaning (filtration). Air cleaning works best alongside the other two.
Filters
- Filters are commonly rated using MERV (Minimum Efficiency Reporting Value); higher MERV filters capture more small particles.
- Check with your contractor before switching to a much higher-MERV filter — some systems can't move enough air through a denser filter.
- Change filters on schedule; a clogged filter reduces airflow and efficiency.
Humidity and ventilation
- Too much humidity encourages mold and dust mites; too little can cause dryness and static.
- Balanced ventilation systems (ERV/HRV) bring in fresh air while recovering energy from the exhaust air.
- Bathroom and kitchen exhaust fans should vent outdoors.
Sources
This guide is general information, not professional, legal or tax advice. Requirements vary by state and locality.
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