Owen Smallwood details his project of using Home Assistant, Prometheus, and Grafana to monitor his natural gas furnace usage during Canada's cold winter months. He aimed to visualize furnace operation times without modifying the furnace by placing a temperature sensor in a heating vent to track temperature increases, which indicate furnace activity. By setting up Home Assistant OS, Prometheus, and Grafana on a home server, and using a Zigbee temperature sensor, Smallwood was able to create a dashboard that visualizes the furnace's running time based on temperature changes recorded every minute. Through Prometheus queries and Grafana's dashboard capabilities, he successfully calculated and visualized the total time the furnace was active, allowing him to analyze the impact of thermostat settings on energy savings. Although his wife opposed lowering the thermostat, Smallwood considered having data to support his energy-saving arguments a personal victory. Looking forward, he plans to use similar methods to monitor his air conditioner's operation and integrate power usage monitoring with the Emporia Vue as part of his home's overall energy observability efforts.