No, an air handler does not include a burner to heat air like a furnace. It can't use natural gas or propane as a source to run and doesn't have a burner to heat air. An air handler is entirely electric and does not require any exhaust ventilation. The only way an air handler can warm air is by using an outdoor heat pump or employing an optional electric heat element, also called heat strips which acts like a toaster heating the warmed airstream. During this mode of heating, the evaporator coil and outdoor unit are turned off.