Skip to content
Menu

Aranet

Aranet4 HOME CO2 Monitor

A battery-powered, e-ink CO2 monitor with a true NDIR sensor and pressure compensation, plus temperature and humidity, that logs to a phone app over Bluetooth.

Check price on Amazon Compare
Aranet4 HOME CO2 monitor on a reflective kitchen surface beside a plate of oranges, showing 1773 ppm.
1 / 6 · hero · hover to zoom

Photo: Aranet

Key facts

CO2 sensor
Non-dispersive infrared (NDIR), with a pressure sensor to correct the CO2 reading
CO2 accuracy (maker)
+/-(30 ppm + 3% of reading) from 0 to 5,000 ppm at 15-35 C and 0-80% RH
Temperature and humidity accuracy (maker)
+/-0.3 C; +/-3% RH
Display
E-ink: CO2 in ppm, temperature and relative humidity, with a three-colour CO2 threshold indicator
Alerts
Visual indicator and an optional buzzer; thresholds adjustable in the app
Measurement interval
1, 2, 5 or 10 minutes (5 by default)
App
Aranet Home app (called Aranet4 by the user manual) over Bluetooth: live data, up to 90 days of history stored in the app with CSV export (the monitor itself keeps 15 days at the default 5-minute interval), pressure readings, settings, firmware updates, Homey integration

Which version should you buy?

This page covers: Aranet4 HOME (TDSPC0H3), single monitor.

  • Aranet4 HOME

    This page

    Model: TDSPC0H3

    What differs
    Standalone CO2 monitor with Bluetooth phone-app access; it does not connect to an Aranet PRO base station.
    Best for
    Homes and offices needing a standalone monitor.
    Check price on Amazon

  • Aranet4 PRO

    What differs
    Adds the radio connection to an Aranet PRO base station for collecting data from multiple sensors.
    Best for
    Buildings using a central Aranet PRO monitoring system.

Watch out

  • HOME and PRO look similar, but only PRO connects to the base station.
  • The CO2-and-radon and radiation-sensor listings are bundles; the standalone Radon detector is a different product.

Why people pick it

  • True NDIR CO2 sensor with pressure compensation and a published +/-(30 ppm + 3%) accuracy
  • E-ink display and AA batteries rated for years: no cable, readable at a glance
  • 90-day history in the app with CSV export

Know before you buy

  • Bluetooth only: no Wi-Fi or cloud dashboard in the HOME version
  • No particulate (PM2.5) or VOC sensor
  • Not for damp rooms: keep it below 85% relative humidity

Full specifications

CO2 sensorNon-dispersive infrared (NDIR), with a pressure sensor to correct the CO2 reading
CO2 accuracy (maker)+/-(30 ppm + 3% of reading) from 0 to 5,000 ppm at 15-35 C and 0-80% RH
Temperature and humidity accuracy (maker)+/-0.3 C; +/-3% RH
DisplayE-ink: CO2 in ppm, temperature and relative humidity, with a three-colour CO2 threshold indicator
AlertsVisual indicator and an optional buzzer; thresholds adjustable in the app
Measurement interval1, 2, 5 or 10 minutes (5 by default)
AppAranet Home app (called Aranet4 by the user manual) over Bluetooth: live data, up to 90 days of history stored in the app with CSV export (the monitor itself keeps 15 days at the default 5-minute interval), pressure readings, settings, firmware updates, Homey integration
CalibrationFactory calibrated; manual calibration in fresh outdoor air with or without the app; automatic mode needs about 8 hours a month in fresh air (around 420 ppm)
Power2 x AA batteries (alkaline pair included)
Battery life (maker estimate)About 2.8 years on alkaline AAs at the default 5-minute interval with Bluetooth on (4.0 years with Bluetooth off; longer on lithium), at 20 C
Operating limits0 to 50 C; not above 85% relative humidity; IP20 (indoor)
Dimensions71 x 71 x 24 mm
Weight104 g with batteries

From manufacturer documentation, checked November 2, 2026. Spotted an error? Tell us.

Featured in

Buying guide

Indoor Humidity Levels and the Best Hygrometers to Measure Them

What a hygrometer measures, EPA's 30 to 50% indoor humidity range, and four hygrometers and air monitors compared on stated accuracy, logging and placement.

Updated November 2, 2026Read

Best picks

Best CO2 Monitors for Bedrooms and Home Offices: NDIR vs eCO2

Best CO2 monitors for bedrooms and home offices, compared on real sensors, logging, calibration and power, with clear picks and the eCO2 buying trap explained.

Updated November 2, 2026Read

Alternatives to consider