There are different “types” of furnaces available, with features to satisfy different budgets and home configurations. A top of the line furnace has both a modulating capacity burner and a variable speed blower. Furnace burners can be single stage, two stage, or modulating capacity. The dual stage and modulating capacity furnaces have superior temperature control, comfort levels and energy efficiency. They are usually somewhat higher in price but can provide a payback from the savings in on energy bills.