The term upflow is used to describe the airflow of a given furnace or air handler. The term is only used to describe the airflow of the indoor system. In an upflow furnace application, the air conditioner evaporator coil will sit above the furnace. In most applications, the furnace air filter will reside to one side of the furnace, near the ground.
Most furnace and heat pump applications in the Indianapolis HVAC market are upflow applications.