Air handlers and furnaces aren't typically installed side by side in Hurricane. If you use a furnace, you probably won’t need to consider an air handler.
Air handlers are frequently paired with heat pumps and manage airflow across your residence. Some units also have extra heating and cooling pieces to assist the heat pump.
A furnace works in a different way by blowing warm air into your vents, which circulate it across your residence. As furnaces rely on combustion chambers to make heat, they don't use some of the parts you'll find in a regular air handler.