A mid-sized home of 2,000 square feet would need approximately 50,000 to 60,000 Btu to heat it properly. With a less efficient furnace operating at 80 percent efficiency this would require a 60,000- to 72,000-Btu furnace.
Electronic Air Cleaner. … As air passes through your heating and cooling system, the electronic air cleaner traps large particles (such as dust and dander) in a prefilter. Then, electrically charged filters attract and trap smaller particles (such as bacteria and mold) to prevent them from recirculating through your home.
Typical costs: Replacing an old oil-fired furnace with a new one typically costs $2,000-$5,000 for a simple installation of a basic model, but it can cost $6,000-$10,000 or more for a larger, more energy-efficient unit with a difficult installation, such as a complex floor plan or hard-to-reach ductwork.