Indoor simple CO2 chart card with background

Who it’s for

Facility managers, HVAC engineers, and building managers ask “how has CO2 trended in this space recently?” The simple chart with background combines compact trend visualization with a full-card color signal readable from a distance.

What it does

A sensor reporting co2 = 720 ppm renders a time-series trend chart on a card whose background color reflects the current severity: green for Good (0–600 ppm), orange for Moderate (600–800 ppm), and red for High (above 800 ppm).

• Full-card background color communicates current severity at a glance from a distance
• Trend chart of CO2 concentration over the selected dashboard time window
• Shows one sensor’s data per widget; add multiple widgets to compare trends and current status across rooms

How to set up

Data keys

Key	Role	Type	Description
co2	Chart series	Timeseries	CO2 concentration in ppm; change the key name to match your device’s telemetry key
Latest	Latest value	Timeseries	The headline figure above the chart. Its own color ranges are where the band colors are edited

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 time window — adjust the dashboard time filter to show the last hour, day, or week of CO2 readings.
• To change the severity thresholds — edit the color ranges on the Latest data key.
• To change the background colors — edit the color of each range on the Latest data key.

Tips

• On a wall display, the colored background signals the current CO2 severity from across the room while the embedded chart shows whether levels are trending upward into the red zone or recovering toward green.
• Use consistent severity colors across all indoor air quality widgets so facilities staff can interpret a red background anywhere on the dashboard without reading the label.
• CO2 trends that cycle between Moderate and High across consecutive occupancy periods without ever reaching Good indicate a chronic ventilation shortfall that requires a permanent HVAC capacity review.