Bedroom air looks good.
CO₂ and particles are low. Settle in for the night.
Know when to open a window, run a purifier or give the AC a break. Terrestream combines indoor readings with outdoor conditions to guide you.
Terrestream sensor
CO₂ and particles are low. Settle in for the night.
Run the purifier before cooking.
Close the windows before rain.
Get timely reminders, then follow your readings to see what changes.
See how it fits your day ↓
Spot rising particles, start filtration and see when the air clears.

See CO₂ rise during homework, then air out when outdoor conditions allow.

Find cool, clean evenings to pause the AC and let outside air do the work.

Outdoor smoke alerts help you know when to close windows and filter indoors.

Check overnight CO₂ patterns and plan a chance to air out before bed.

Get a reminder to start filtration ten minutes before cooking.

Check local pollen conditions before opening the windows.

Follow humidity after a shower and see when the fan has done its job.

Get a reminder to air out after vacuuming, when outdoor conditions allow.

A timely reminder helps you close the windows before the weather turns.

Avoid bringing in moisture your AC will have to remove. Check humidity before opening up.

Follow the VOC Index after unpacking, then air out when outdoor conditions allow.
Rising CO₂ calls for fresh air. Outdoor pollution can change the plan. Terrestream considers both.
Fresh air would help
Mild weather
Use filtration for particles. Air out when outdoor conditions improve.
Filtration does not lower CO₂.
From cooking and cleaning to a change in the weather.
Dedicated CO₂ sensing and laser particle detection help you follow the changes that ventilation and filtration make.
Carbon dioxide
Particles ≤ 2.5 µm
Particles ≤ 10 µm
Calculated air quality index
Organic gas changes
Oxidizing gas changes
Particles ≤ 1 µm
Particles ≤ 4 µm
Room warmth
Moisture in the air
Barometric pressure
Room brightness
Sensing technology from Sensirion, Bosch and Texas Instruments.
See the measurement evidenceNo subscription required.
No. The apps, web dashboard and account are free, and core recommendations are included.
Each sensor measures the room it is in. Add sensors where you sleep, work or spend time, and compare them in the app.
Plug it into USB-C power; it has no battery. The 6 ft (1.8 m) USB-C cable and power adapter are in the box. Readings show on its own screen with no Wi-Fi or account. For the app and connected guidance, connect it to 2.4 GHz Wi-Fi and create a free account.
It measures 69 × 65 × 111 mm (2.72 × 2.56 × 4.37 in) and weighs 6.7 oz (190 g).
It measures your air and helps you decide when to ventilate or filter. You take the action. It does not replace a purifier, smoke alarm or carbon-monoxide alarm.
Ships the next business day via FedEx. Return it within 30 days of delivery, even if you’ve opened and used it. You pay return shipping.
30-day returns · 1-year limited warranty
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