Air Purification in San Francisco, CA

Air Purification in San Francisco, CA

Cleaner indoor air matters in San Francisco homes. Coastal humidity, marine aerosols, urban traffic, and seasonal wildfire smoke combine to create unique air quality challenges for Bay Area residents. Whole-house air purification provides continuous protection across living spaces reducing allergens, smoke, dust, pet dander, and many airborne bacteria and viruses. Whole-house options (media filters, electronic air cleaners, HEPA/medical-grade systems), how they perform, what installation and maintenance look like, and how to pair purification with existing HVAC systems and service agreements for reliable, measurable results. Air Flow Pros can help you choose a system that fits your home.

Why whole-house air purification matters in San Francisco, CA

• Wildfire smoke events create spikes in PM2.5 that quickly penetrate homes. Whole-house systems reduce smoke particles in the living space more effectively than room units alone.
• Older buildings and multiunit homes commonly have leaky ducts and shared ventilation, increasing pollutant entry. In-duct purification treats air for the entire house.
• The marine layer and high humidity can increase mold spores and indoor allergens. Integrated solutions that include filtration plus humidity control help minimize these risks.
• Continuous filtration prevents build up of traffic-related and construction dust common in urban neighborhoods.

Whole-house air purification types and where they work best

Media filters (in-duct)

• Common MERV ratings run from MERV 8 up to MERV 16 for whole-house installations.
• MERV 8 to 11: effective for large particles like dust, pollen, and pet dander.
• MERV 13 to 16: capture finer particles including many PM2.5 particles and some respiratory aerosols; often recommended during wildfire season or for households with allergy and asthma concerns.

Best for homeowners who want low-maintenance, passive filtration integrated into HVAC.

• Electronic air cleaners (electrostatic precipitators and electronic collectors)
• Use charged plates or media to capture very small particles. Can achieve high particle removal for ultrafine particulates.
• Require periodic cleaning of collection cells. Older models can produce ozone; choose ozone-safe certified units when assessing options.

HEPA and medical-grade systems

• True HEPA captures 99.97 percent of particles down to 0.3 micron. Highly effective against smoke, pollen, and most airborne allergens.
• Whole-house HEPA usually requires a dedicated fan or a modified HVAC blower because HEPA has higher resistance than typical media filters.
• Ideal for severe allergy or asthma sufferers and households seeking the highest particulate removal performance.

Supplemental technologies

• UV germicidal irradiation (UVGI) targets microbes on coils or in the ductwork. Works best paired with filtration for combined particulate and biological control.
• Energy recovery ventilators (ERVs) and heat recovery ventilators (HRVs) manage fresh air intake while limiting pollutant entry.

Performance metrics explained in plain terms

Particle sizes and targets

• PM2.5 refers to particles 2.5 microns and smaller. Wildfire smoke is largely PM2.5 and is a primary concern in San Francisco.
• HEPA filters: remove 99.97 percent of particles at 0.3 micron size.
• MERV 13 filters: significantly reduce particles in the 0.3 to 3.0 micron range and are commonly recommended for smoke and viral mitigation.

Removal rate and equivalent CADR

• For whole-house systems, effective cleaning depends on both filter efficiency and airflow. Higher airflow at high efficiency equals faster removal.
• A common target for meaningful reduction of pollutants is increasing the equivalent clean air delivery so the home achieves several air changes per hour. Exact ACH depends on home size and system capacity.

Pressure drop and system compatibility

• Higher efficiency filters and HEPA add resistance. Before upgrading, measure static pressure and confirm the HVAC blower can handle the increased load to maintain airflow and comfort.

How installation and diagnostics work

Initial assessment

• Technicians inspect the HVAC unit, measure static pressure, check blower capacity, evaluate duct condition and leakage, and measure baseline indoor particulate levels if required.
• For apartments or older homes, duct sealing and return placement are evaluated to ensure whole-house coverage.

Installation options

• In-duct media filter: installed in the return plenum or filter slot. Quick to install with minimal duct modification for most systems.
• Electronic in-duct cleaner: mounted in the return or supply run with electrical connection and access panel for cell cleaning.
• Whole-house HEPA: may require a dedicated cabinet and booster fan or replacement of the furnace blower with a higher-capacity unit.
• Supplemental portable HEPA units: used in conjunction with whole-house systems for rooms with lingering sources or during wildfire events.

Post-install testing

• Measure airflow and static pressure to verify HVAC performance.
• Optional particle counts before and after installation verify real-world reduction of PM2.5 and other particulates.

Maintenance requirements you should expect

Media filters

• Prefilters: inspect every 1 to 3 months.
• High-efficiency media (MERV 13+): typically every 6 to 12 months, with frequency increasing during wildfire season or in dusty environments.

Electronic air cleaners

• Clean collector cells every 3 to 6 months depending on loading.
• Inspect power supplies and ionizing components at least annually.

HEPA systems

• Replace HEPA cartridges per manufacturer guidance, often every 1 to 3 years depending on usage and pollutant load.
• Replace prefilters more frequently to protect the HEPA element.

UV lights and other components

• Replace UV lamps annually to maintain germicidal intensity.
• Keep records of component changes and performance checks.

Recommended pairings and system considerations for San Francisco homes

• Pair filtration upgrades with duct sealing and balancing to make filtration work for the whole home, not just where vents are close.
• Use variable-speed blowers and a thermostat fan schedule to increase run time without major energy penalties. Continuous fan operation raises the effective clean air delivery.
• Combine high-efficiency filtration with ventilation control. During wildfire smoke events, reduce outdoor air intake and rely on filtration to clean indoor air. At other times, use ERVs/HRVs to bring in controlled fresh air without excess pollutants.
• For allergy and asthma households, a HEPA-level solution or MERV 13+ whole-house filter plus UVGI provides broad protection against particles and many biological contaminants.

Service agreements and long-term performance

• A service agreement that includes scheduled filter changes, cell cleaning, annual inspections, and seasonal performance tests keeps systems operating at rated efficiency.
• During the Bay Area wildfire season, consider timing extra checks before high-risk months to ensure filters are fresh and fans are operating properly.
• Regular maintenance preserves HVAC efficiency and reduces the risk of reduced airflow or equipment stress caused by clogged filters.