Carbon dioxide indoors
Every exhale adds COâ‚‚ to the room. Past about 1,000 ppm, focus slips. Past 1,500, headaches.
Articles tagged "Ventilation"
Filtered view. Return to /learn for the full reference.
All articles
Bedroom overnight: the COâ‚‚ climb you sleep through
Two adults in a closed bedroom can push COâ‚‚ past 2,000 ppm by 4 AM. The math is unforgiving.
ASHRAE ventilation rates: the math behind "open a window"
ASHRAE 62.1 covers commercial; 62.2 covers homes. Both give you a number in CFM per person.
Wind and infiltration: how the outdoors gets in
Outdoor wind drives air through small cracks and gaps in your building. Higher wind = more outdoor air entering, whether you want it or not.
Open vs. closed windows
The single most consequential daily decision the dashboard helps you make. Six outdoor signals, three indoor signals, one answer.
Meeting rooms and COâ‚‚
Eight people in a 6×8 m room with the door closed will hit 2,000 ppm in under an hour. The cognitive cost is real and measurable.
Demand-controlled ventilation
Run the HVAC harder when people are in the room, less when they aren't. COâ‚‚ sensors are how it knows.
Building type priors
Apartments, townhomes, detached single-family, and commercial buildings each have characteristic air-quality patterns. The AI uses the building type as a structural prior.
Ventilation approaches, compared
Open windows, range hood, HRV/ERV, demand-controlled ventilation. Different ways to bring fresh air in and stale air out.
What to do when COâ‚‚ stays high
Sustained COâ‚‚ above 1,000 ppm means ventilation is not keeping up with occupancy. Four diagnostic paths.
Reducing COâ‚‚ indoors: the ventilation ladder
COâ‚‚ is what people exhale. The only durable answer is moving more outside air in. Here is the cost-ordered ladder, from free to capital project.
Spot ventilation: kitchen and bath exhaust done right
Task-specific exhaust handles the worst pollutant sources at their origin. Sized correctly and ducted to outdoors, it does more than whole-house ventilation can.
IAQ tradeoffs with energy: ventilation has a heating bill
Every cubic foot of outside air you bring in is air you have to heat or cool. In some climates "just open windows" is correct; in others it is the most expensive intervention you can pick.
COâ‚‚ sensor accuracy and ventilation
COâ‚‚ is the clearest occupancy and ventilation signal in most rooms, but placement, calibration assumptions, and recovery time still shape the interpretation.
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