Air handlers and furnaces aren't usually installed in the same home in Elkhart. If you have a furnace, you most likely won’t need to think about an air handler.
Air handlers are typically used with heat pumps and control airflow throughout your home. Some systems also provide extra heating and cooling pieces to support the heat pump.
A furnace heats in a different manner by blowing warm air into your vents, which send it throughout your home. As furnaces rely on combustion chambers to create heat, they don't have some of the parts you'll find in a standard air handler.