Build a CO2-threshold ventilation-check pattern using a Kaiterra Sensedge monitor as a complementary signal alongside radon monitoring

Steps

1. Poll a fixed indoor CO2 monitor's latest reading (e.g., Kaiterra Sensedge via its /v1/devices/{deviceId} endpoint) on a regular interval such as every 5-15 minutes, since the public API is pull-based, not webhook-based.
2. Compare the returned CO2 ppm value against a fixed action threshold (commonly referenced informally around 1,000 ppm per ASHRAE 62.1 ventilation guidance) to flag under-ventilated spaces.
3. Use a sustained-CO2 alert as a secondary trigger prompting an HVAC/ventilation check alongside — not instead of — a dedicated radon monitor reading, since poor ventilation is a shared underlying condition for both CO2 buildup and radon accumulation.
4. Log the CO2 stream and any co-located radon monitor's stream on a shared timeline so facilities staff can see whether a ventilation change correlates with a radon-level change.
5. Rate-limit and cache polling per Kaiterra's documented API key usage guidance to avoid hitting per-key request limits when monitoring many spaces.