AirGradient ONE

At a glance

• In its favour
• Plain fact
• Worth knowing
• Not stated by the maker

• In its favour: Import whole nights from its CSV
• Plain fact: Needs a plug (USB-C)
• Plain fact: Self-calibration on; you can turn it off
• Not stated by the maker: Altitude correction not stated

With HouseExhale

The app looks at your bedroom’s CO₂ across the night and checks it against the 800 ppm goal. Here’s how this monitor’s nights get in.

Finding last night’s high

Open the AirGradient dashboard each morning and look at last night’s CO₂ history. Note the highest point while people were asleep, and type it in the app.

Its export is a CSV the app can import, so you can bring in whole nights instead of typing.

Where to put it: about head height, at least 2 ft from anyone’s face, away from windows, doors and vents, and in the same spot every night. More on placement

Calibrating it

• Plain fact: Self-calibration on; you can turn it offOn by default, can be turned off (every 7 days; turn it off in the dashboard under Edit Calibration)

Outdoor air is about 425 ppm. Outside in the shade, a good monitor settles between about 400 and 450 within 15 to 30 minutes. Many monitors treat fresh air as 400, so 400 to 420 is normal. Can I trust my monitor?

Specs

Model

I-9PSL

Sensor and accuracy

True CO₂ (NDIR, Senseair S8), ±(40 ppm + 3%), plus particles and VOCs

Self-calibration

On by default, can be turned off (every 7 days; turn it off in the dashboard under Edit Calibration)

Corrects for altitude

Not stated by the maker

Also measures

PM2.5 (and PM1 and PM10), TVOCs, NOx, temperature and humidity

CO₂ range

400–10,000 ppm (Senseair S8)

How often it updates

Not stated by the maker

Power

USB-C only; bring a 2 A adapter

Screen

1.3-inch OLED

History

Sends readings over Wi-Fi to AirGradient’s dashboard, which exports a CSV

App

The AirGradient dashboard, on the web. AirGradient’s only App Store listing is “AirGradient Map”; no phone app for the ONE was found.

Exports a CSV

Yes

Connects by

Wi-Fi (2.4 GHz); the product page also lists Bluetooth LE. A cellular version (I-9PSL-CE) exists. Readings go to AirGradient’s online dashboard. Home Assistant can read it on the home network, and keeps working with the cloud connection off.

Alarm

No buzzer mentioned. Eleven colored LEDs on the front show air quality and can be switched off completely; alerts are set up in the dashboard. No default CO₂ level given.

Smart home

Home Assistant: the official AirGradient integration works locally and finds the monitor by itself (AirGradient says Home Assistant 2024.6 or newer with the latest firmware; HA’s docs say firmware 3.1.1 or newer). It reads CO₂ and has a self-calibration (ABC days) setting. No Apple Home, Google, Alexa or Matter support found.

Size

Sources disagree: 131.2 × 131.2 × 36.2 mm on the spec sheet; 130 × 130 × 35 mm on the product page

Weight

Sources disagree: 230 g without the cable on the spec sheet; 350 g on the product page

Works in

Not stated by the maker

In the box

The monitor and a 2 m USB-C to USB-A cable. No power plug: bring a 5 V, 2 A USB adapter.

Warranty

12 months for the assembled monitor; the kit has no warranty

Specs from the maker’s own pages, checked October 12 and October 17, 2026. “Not stated by the maker” means no maker page we could open says.

Turning ventilation up

Home Assistant’s AirGradient integration reads its CO₂ over your own network (firmware 3.1.1 or later), and keeps working with its cloud connection turned off. Home Assistant: AirGradient integration

With a smart-home relay on a ventilator’s high-speed input, that reading can turn an HRV or ERV up at 750 ppm and back down at 650. Ventilator makers don’t document this, so check your unit’s manual first, and keep to low-voltage inputs.

CO₂ controls · Make the system you have turn up by itself

Before you buy

• Worth knowing: Check the price before buyingWe couldn’t confirm a current store price, or it was out of stock, when we checked.
• Plain fact: About $230 before tax and shippingAssembled; the kit was $138. We couldn’t open AirGradient’s store in October, and it ships from Thailand.

About $230, checked October 2026; check before buying. Prices change often; we checked at the maker’s store and large US retailers. Any monitor that measures true CO₂ works with HouseExhale, and one is enough: move it between rooms.

AirGradient ONE at AirGradient (opens in a new tab)

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