HEPA purifiers: the CADR math
A HEPA filter is the most effective single intervention for indoor particulates. Sizing it correctly is the part most people get wrong.
Articles tagged "Filtration"
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The Corsi-Rosenthal box-fan filter
A $50 box fan, four MERV-13 furnace filters, and twenty minutes of construction. CADR comparable to a $400 commercial unit.
HVAC MERV ratings: what your furnace filter actually does
MERV 8 catches dust. MERV 13 catches viruses. MERV 16 catches almost everything HEPA does. Most homes ship with MERV 6.
How long until the air clears
CADR, room volume, air changes per hour. The math behind "the room should clear in about 20 minutes."
Filtration approaches, compared
HEPA, MERV, Corsi-Rosenthal. Three filtration paths to the same goal. Cost, performance, deployability differ in different directions.
Reducing PM2.5 indoors: filtration plus source control
Two levers: stop making fine particles, and remove them when they appear. CADR-sized HEPA in occupied rooms plus a MERV-13 HVAC filter does most of the work.
Breathe Better. Live Smarter.
Turn air-quality knowledge into action.
One sensor. Twelve signals. Indoor readings connected to outdoor context and plain-English recommendations. Everything you just read can be measured live in your own home.
$249 USD one-time
Buy Terrestream Explore the sensor- No subscription required
- 30-day returns
- 1-year limited warranty
- Fast shipping via FedEx
Six sensors. Twelve signals.
Built on genuine Sensirion, Bosch, and Texas Instruments sensors.
- COâ‚‚
- IAQ
- VOC
- NOâ‚“
- PM1
- PM2.5
- PM4
- PM10
- Temperature
- Humidity
- Pressure
- Light
Included
- In the box: the sensor, USB-C cable, power adapter, and printed field guide
- Dashboard and mobile app included
- Privacy-first air data
Works with
- Home Assistant
- MQTT
Home Assistant
MQTT