Air handlers and furnaces aren't usually installed together in Girard. If you use a furnace, you likely shouldn’t need to consider an air handler.
Air handlers are often paired with heat pumps and deliver airflow around your home. Some models also offer backup heating and cooling components to support the heat pump.
A furnace heats differently by blowing hot air into your vents, which send it across your home. As furnaces use combustion chambers to create heat, they don't need some of the parts you'll see in a standard air handler.