IoT building monitoring that runs on less than 5 watts

Building monitoring usually fails because the hardware is too expensive or too power-hungry to deploy at scale. We optimized for the opposite: nodes cheap enough to put on every floor and efficient enough to forget about.

Each node is an ESP32 reading temperature, humidity, and occupancy. Data flows over MQTT — a lightweight protocol that survives flaky Wi-Fi far better than HTTP — to a cloud InfluxDB instance.

Why MQTT and not a custom REST API? Because it’s designed for exactly this: many devices, low bandwidth, and unreliable networks. It keeps every node under 5 watts and the monthly cloud bill trivial.

On top of the data sits Grafana. Facilities teams get a real-time dashboard and threshold alerts by SMS and email — so a temperature spike in a server room triggers a response before anyone walks in.

The outcome: 24/7 monitoring across three floors with sub-2-second latency, and incident response times down 60%. Physical spaces can “know themselves” without breaking the budget.