Score every home by HVAC age proxy (year_built / year_remodeled), property value, and extreme-weather exposure. Find replacement candidates before the unit fails.
HVAC replacement is age-driven: residential systems last 15-20 years on average. CurbSight scores every property in your territory by age proxy (year_built) and weather extremity (NOAA temperature data is on the roadmap; for now, hail/wind storms in the zip are a directional weather-stress signal). The trade is less storm-driven than roofing, but the property-intelligence-on-every-knock pattern is the same.