Air handlers and furnaces aren't often used together in Edmonton. If you rely on a furnace, you likely won’t need to think about an air handler.
Air handlers are frequently paired with heat pumps and manage airflow around your residence. Some models also have backup heating and cooling components to help the heat pump.
A furnace heats in a different manner by sending warm air into your vents, which move it throughout your residence. As furnaces depend on combustion chambers to produce heat, they don't need some of the pieces you'll spot in a normal air handler.