Outdoor air, HVAC schedules, and air distribution
Ventilation dilutes indoor contaminants, but performance depends on outdoor-air delivery, distribution, maintenance, controls, and how the room is occupied.
Field dossier / 03 Technology
Clean-air tools are a stack, not a gadget category.
The important technologies reduce sources, dilute contaminated air, remove particles, inactivate pathogens, verify performance, or help operators know when a room has drifted out of bounds.
IAQng should be practical here: what works, when it works, what it costs to maintain, what can go wrong, and what claims deserve skepticism.
Technology map
What can actually change the room?
MERV filters, portable HEPA, and CADR
Filtration removes particles from air. The practical questions are sizing, pressure drop, noise, placement, filter changes, and clean-air delivery rate.
Corsi-Rosenthal boxes and clean-air kits
Low-cost fan-filter devices helped communities, schools, and advocates make clean-air action tangible during COVID-19 and wildfire-smoke events.
Upper-room germicidal ultraviolet systems
Upper-room GUV can inactivate airborne pathogens when designed, installed, commissioned, and maintained correctly.
222 nm far-UVC
An emerging approach with promising research and real safety, standards, dose, maintenance, and procurement questions still to be handled carefully.
Low-cost air sensors and CO2 monitors
Lower-cost sensors and CO2 monitors make ventilation and particle problems visible to operators and the public, but placement, calibration, and interpretation decide whether the readings can be trusted.
Building automation, demand control, and room-level interventions
The most useful systems connect sensing to action: change airflow, dispatch service, reposition cleaners, flag filters, or escalate a room before risk persists.
People and organizations
Names worth following.
Richard Corsi and Jim Rosenthal
The Corsi-Rosenthal box made filtration understandable, buildable, and community-scalable.
David Brenner / Columbia
A central research voice in far-UVC and its potential for reducing airborne pathogen transmission.
CDC / NIOSH ventilation resources
Practical public guidance for ventilation, air cleaning, and UVGI in workplaces and public settings.
AHAM and CADR
Clean-air delivery rate remains a useful purchasing and sizing concept for portable air cleaners.
Procurement questions
What operators should ask before buying.
- What contaminant or exposure pathway does this technology address?
- How is performance sized for the actual room volume, occupancy, layout, and use pattern?
- Who maintains it, replaces filters or lamps, verifies placement, and documents failures?
- Does it generate ozone, byproducts, noise, glare, drafts, privacy risk, or operational burden?
- How does the tool connect to dispatch, cleaning, ventilation, filtration, or infection-prevention workflows?