Air handlers and furnaces aren't usually installed side by side in the Niagara Region. If you use a furnace, you probably won’t need to think about an air handler.
Air handlers are typically paired with heat pumps and manage airflow throughout your residence. Some units also offer backup heating and cooling pieces to support the heat pump.
A furnace heats in a different manner by sending hot air into your vents, which circulate it around your residence. Because furnaces have combustion chambers to make heated air, they don't have some of the parts you'll find in a regular air handler.