Trane systems can be built around more than a single furnace or outdoor AC unit. The residential lineup includes furnaces, air conditioners, heat pumps, air handlers, ductless systems, thermostats, zoning controls, and indoor air quality equipment. Star City works with these interconnected components to diagnose performance problems, maintain existing Trane equipment, and help Lincoln homeowners plan system upgrades that make sense for the way their homes are heated and cooled.