Indoor CO2 card

Who it’s for

Facility managers, HVAC engineers, and building managers ask “is CO2 in this space currently at a healthy level?” They monitor indoor carbon dioxide continuously to ensure ventilation is keeping up with occupancy and that occupants are not experiencing the fatigue and reduced concentration that elevated CO2 causes.

What it does

A sensor reporting co2 = 720 ppm displays the reading on a color-coded card: green for Good (0–600 ppm), orange for Moderate (600–800 ppm), and red for High (above 800 ppm).

• Live CO2 reading in ppm with automatic color coding across three severity bands
• Severity bands reflect typical indoor air quality thresholds for occupied spaces
• Shows one sensor’s reading per widget; add multiple widgets to monitor different rooms or zones

How to set up

Data keys

Key	Role	Type	Description
co2	Main value	Timeseries	CO2 concentration in ppm; change the key name to match your device’s telemetry key

The widget ships with a simulated function datasource key labeled CO2 level, so it draws random values until you point the datasource at a device and rename the key.

To point it at your own device: open the dashboard in edit mode, open the widget’s Datasources, pick the entity or entity alias, and replace the function key with the key your device reports.

Value ranges

Range (ppm)	Level	Color
0–600	Good	Green
600–800	Moderate	Orange
800+	High	Red

How to customize

• To change the severity thresholds — edit Icon color ranges and Value color ranges; set the same boundaries in both so the icon and the number always agree.
• To change the band colors — edit the color of each range in Icon color ranges and Value color ranges.
• To rename the units label — change the Units field in the widget settings if needed.

Tips

• CO2 rises proportionally with occupancy in a room; a sharp climb from 400 ppm toward 800 ppm during a meeting indicates ventilation is insufficient for the number of people present and the HVAC setpoint should be reviewed.
• Readings above 800 ppm in offices are associated with measurable decreases in cognitive performance; posting this card on a shared dashboard gives meeting room occupants a visual cue to open a window or request HVAC support.
• For HVAC commissioning, compare CO2 trends in multiple rooms on the same dashboard to identify zones where the supply air volume is inadequate relative to peak occupancy.