Learn: Gases - Terrestream

Carbon dioxide indoors

Every exhale adds CO₂ to the room. Past about 1,000 ppm, focus slips. Past 1,500, headaches.

Updated 2026-05-25

VOCs: the invisible smell

Volatile organic compounds are the carbon-based gases evaporating off everything: cooking, candles, paint, new furniture. Some are merely annoying. Some are not.

Updated 2026-05-25

NOₓ: gas stoves, traffic, asthma

Nitrogen oxides come from combustion. Indoors, the main source is a gas stove. The health link with childhood asthma is robust.

Updated 2026-05-25

Pollen and ozone: the outdoor numbers that change your indoor advice

When outdoor ozone or pollen is high, "open a window" stops being good advice.

Updated 2026-05-25

CO vs CO₂: we measure one, not the other

Carbon monoxide and carbon dioxide sound alike and the abbreviations look alike. They are completely different gases. Terrestream measures CO₂ only.

Updated 2026-05-25

Sulfur dioxide: the outdoor number for fuel and fire

SO₂ comes from burning sulfur-bearing fuels: coal, heavy oil, diesel ships, volcanic activity, and wildfires. The device does not measure it; the dashboard pulls it from Open-Meteo.

Updated 2026-05-25

Cloud cover and photochemistry

Cloudy days produce less outdoor ozone. Sunny days produce more. The dashboard uses cloud cover to predict tomorrow's ozone today.

Updated 2026-05-25

Solar radiation and air chemistry

Direct radiation, diffuse radiation, shortwave total. The numbers behind outdoor ozone, indoor lux, and the circadian signal all come from the same place.

Updated 2026-05-25

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