Yes – replacing an old, inefficient furnace with a newer model that has a higher annual fuel utilization efficiency (AFUE) rate will save you money on your annual heating costs. You can calculate your savings by subtracting the old unit’s AFUE from the new unit’s AFUE (for example, 90% – 78% = 12%) and then multiplying the result by your annual heating costs. Although more efficient units can lead to significant cost savings over the life of the unit, they do cost more up front.