The COVID-19 pandemic highlighted the importance of indoor ventilation. But even beyond pandemic concerns, fresh air ventilation supports health, comfort, and air quality.
Why Ventilation Matters
Health Benefits:
Dilutes airborne contaminants
Reduces pathogen concentration
Removes CO2 from occupied spaces
Clears odors and VOCs
Comfort Benefits:
Prevents stuffiness
Controls humidity
Reduces stale air sensation
Improves cognitive function
Ventilation Strategies
Natural Ventilation:
Opening windows when outdoor conditions allow
Cross-ventilation through opposite openings
Stack effect in multi-story homes
Free but weather-dependent
Mechanical Ventilation:
Exhaust fans (bathrooms, kitchens)
Supply fans bringing in outdoor air
Balanced systems (equal supply and exhaust)
Works regardless of weather
Energy Recovery Ventilators (ERV):
Bring in fresh air
Transfer energy from outgoing air
Maintain efficiency
Ideal for Bay Area climate
Heat Recovery Ventilators (HRV):
Similar to ERV
Better for humidity control
Best for heating-dominated climates
Measuring Ventilation Adequacy
ASHRAE Standards:
Recommend 0.35 air changes per hour or 15 CFM per person.
CO2 Levels:
Outdoor: ~400 ppm
Good indoor: <800 ppm
Stuffy/inadequate: >1000 ppm
Problematic: >1500 ppm
Simple Tests:
Lingering odors indicate poor ventilation
Foggy windows suggest inadequate air exchange
CO2 monitors provide accurate readings
Bay Area Considerations
Wildfire Season:
Must balance fresh air needs with smoke protection. High-quality filtration becomes essential.
Mild Climate:
Natural ventilation works much of the year, reducing mechanical ventilation needs.
Older Homes:
Many Bay Area homes are naturally "leaky," providing some unintentional ventilation but lacking control.
Good ventilation is fundamental to a healthy home. Modern solutions provide fresh air without sacrificing energy efficiency or indoor air quality.