Variable speed motor(s)
The fan motor inside Trane's variable speed air handlers is designed to vary its speed based on your home's heating and air conditioning requirements. Working in conjunction with the thermostat, it keeps the appropriate temperature air (e.g. warm air on cold days) circulating throughout your home, reducing temperature variances in your home. It also provides greater air circulation and filtration, better temperature distribution, humidity control, higher efficiency, and quiet performance.