Research & data
Built on what the air actually contains
Every design decision in this system traces back to measured local air quality data — particulate counts, seasonal pollution cycles, and indoor-outdoor exchange rates specific to Southern California.
0yr
Monitoring period
Continuous outdoor sampling before design began. West Costa Mesa is a residential and industrial neighborhood with air q…
0.00%
HEPA capture rate
At 0.3 µm — the most penetrating particle size
0 CFM
Airflow rate
Sized to achieve 4–5 ACH in a 500 sq ft room
0.00″
HEPA media depth
Deeper bed = lower face velocity = longer filter life
Why local data matters
National air quality averages mask significant regional variation. A system tuned to the EPA's national PM2.5 mean will underperform in areas with wildfire smoke, coastal marine layer, or heavy traffic corridors.
This project began with two years of hyperlocal monitoring before a single filter was specified. The data shaped every component choice — carbon bed depth, HEPA grade, fan CFM, and vent placement angle.
Seasonal particulate levels — Southern California
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Peak PM2.5: Nov–Jan (wildfire + inversion) · Peak PM10: Apr–Jun (wind / pollen)
Pollutant profile
What the local air actually contains
Pollutant
Description
Local peak
Peak season
Filter stage
PM2.5
Fine particulate matter under 2.5 microns. Primary driver of HEPA specification.
68 µg/m³
Oct – Jan (wildfire + inversion)
Stage 2 — HEPA
PM10
Coarse dust, pollen, and road debris. Captured before HEPA stage.
112 µg/m³
Apr – Jun (wind / pollen)
Stage 1 — Carbon pre-filter
VOCs
Volatile organic compounds from traffic, solvents, and combustion.
0.38 ppm TVOC
Year-round (traffic corridor)
Stage 1 — Activated carbon
NO₂
Nitrogen dioxide from vehicle exhaust. Indicator of combustion proximity.
52 ppb
Nov – Feb (temperature inversion)
Stage 1 — Carbon bed
Infiltration analysis
How much outdoor pollution enters the building
Simultaneous indoor and outdoor sensors measured the fraction of each pollutant that penetrates the building envelope without active filtration. VOCs infiltrate most aggressively — nearly 85% of outdoor concentration — while coarse PM10 is partially blocked by the structure itself.
These ratios directly informed the carbon bed sizing: a deeper activated carbon stage was required to address the high VOC infiltration rate that a HEPA-only system would miss entirely.
Indoor / outdoor ratio — no active filtration
Measured at test structure without active filtration.■ Indoor ■ Outdoor baseline
Measurement methodology
How the data was collected and applied
01
Outdoor baseline sampling
Laser particle counters placed at roof level — the actual intake point — logged PM1, PM2.5, and PM10 at 5-minute intervals across all seasons.
02
Indoor-outdoor ratio analysis
Simultaneous indoor and outdoor measurements established the infiltration ratio for the test structure, revealing which pollutants penetrate most aggressively through the building envelope.
03
Filter media selection
Candidate HEPA and carbon media were bench-tested against the measured local pollutant profile — not generic lab aerosols — to confirm real-world capture efficiency.
04
CFM and ACH modeling
Room volume, infiltration rate, and target air changes per hour were used to specify fan output. 170 CFM achieves 4–5 ACH in a 500 sq ft room with 8 ft ceilings.
References
Data sources and standards
2024–2026
EPA AQS Data — South Coast AQMD
Hourly PM2.5 and PM10 readings from the nearest EPA monitoring station, used as calibration reference.
2025
CARB Wildfire Smoke Guidance
California Air Resources Board seasonal PM2.5 projections for wildfire corridors in Southern California.
2022
ASHRAE 62.2 — Ventilation for Acceptable Indoor Air Quality
Standard used to derive minimum outdoor air exchange rates and ACH targets for residential spaces.
2023
NIOSH HEPA Filter Performance Study
Benchmark data for HEPA capture efficiency at 0.3 µm across varying face velocities.
Interested in the data or methodology?
I'm open to sharing raw datasets, sensor logs, and filter test results with researchers, engineers, and potential collaborators.
Get in touch