Air handlers and furnaces aren't typically installed side by side in Niagara Falls. If you rely on a furnace, you probably shouldn’t need to think about an air handler.
Air handlers are frequently paired with heat pumps and manage airflow throughout your residence. Some systems also offer backup heating and cooling pieces to assist the heat pump.
A furnace heats in a different way by pushing hot air into your vents, which circulate it around your house. Because furnaces depend on combustion chambers to make heated air, they don't have some of the parts you'll find in a regular air handler.