For the millions of Americans with allergies and asthma, indoor air quality directly impacts daily comfort and health. Your HVAC system plays a crucial role in managing airborne triggers.
Common Indoor Air Triggers
Allergens:
Dust mites
Pet dander
Pollen
Mold spores
Irritants:
Dust particles
Volatile organic compounds (VOCs)
Tobacco smoke
Strong odors
Biological Contaminants:
Bacteria
Viruses
Fungi
How HVAC Systems Help (and Hurt)
Potential Benefits:
Filtration removes airborne particles
Controlled humidity limits mold and dust mites
Circulation prevents stagnant air pockets
Fresh air ventilation dilutes indoor pollutants
Potential Problems:
Dirty systems circulate contaminants
Poor maintenance breeds mold
Inadequate filtration spreads allergens
Ductwork harbors dust and debris
Filtration Upgrades
Understanding MERV Ratings:
MERV 1-4: Basic filtration, minimal allergen capture
MERV 5-8: Better dust capture, some pollen
MERV 9-12: Good allergen removal, pet dander
MERV 13-16: Hospital-grade, catches most allergens
MERV 17-20: HEPA-level, maximum filtration
Recommendations:
Minimum MERV 11 for allergy sufferers
MERV 13+ for asthma or severe allergies
Verify your system can handle higher MERV ratings (airflow restriction)
HEPA Filtration:
True HEPA filters capture 99.97% of particles 0.3 microns and larger:
Standalone HEPA units for bedrooms
Whole-home HEPA systems (bypass design)
HEPA-type filters (less effective but better airflow)
Humidity Control
The Ideal Range: 30-50% relative humidity
Too High (>50%):
Dust mites thrive
Mold growth accelerates
Bacteria multiply
Too Low (<30%):
Dry airways more susceptible to irritation
Dust particles stay airborne longer
Static electricity increases
Solutions:
Whole-home humidifiers (winter)
Whole-home dehumidifiers (summer)
Monitor with hygrometers
Address moisture sources
Air Purification Technologies
UV-C Germicidal Lights:
Kill mold, bacteria, viruses in air and on coils
Installed in ductwork or air handler
Continuous protection
Cost: $500-$1,500 installed
Electronic Air Cleaners:
Use ionization to charge particles
Particles collect on plates or surfaces
Require regular cleaning
Cost: $500-$1,200
Photocatalytic Oxidation (PCO):
Breaks down VOCs and odors
Neutralizes biological contaminants
Works with UV and catalyst
Cost: $600-$2,000
Activated Carbon Filters:
Absorb gases and odors
Remove VOCs
Must be replaced periodically
Cost: $100-$400 per year
Duct Cleaning and Sealing
When Duct Cleaning Helps:
Visible mold growth
Vermin infestation
Excessive dust/debris
After renovation work
Duct Sealing Benefits:
Prevents unfiltered air entry
Improves filtration effectiveness
Reduces infiltration from attics/crawlspaces
Aeroseal or mastic sealing recommended
Maintenance for Allergy Sufferers
Monthly:
Check and replace filters
Wipe supply registers
Monitor humidity levels
Quarterly:
Clean around outdoor unit
Check drainage
Inspect visible ductwork
Annually:
Professional maintenance
Coil cleaning
Blower cleaning
Drain treatment
Creating an Allergy-Friendly Home
Bedrooms:
Highest priority for air quality
Consider standalone HEPA purifier
Keep pets out
Use allergen-proof bedding covers
Whole Home:
Maintain 30-50% humidity
Use high-MERV filters
Run fan to improve filtration
Ventilate when outdoor air quality is good
Bay Area Specifics:
Plan for wildfire smoke events
Address coastal humidity
Consider pollen seasons
For allergy and asthma sufferers, investing in indoor air quality isn't a luxury—it's a health necessity that can significantly improve quality of life.