It comes down to personal preference, but here are some points to consider: In Southern California, we often do not use our furnaces enough to recover the added expenses through energy savings. High-efficiency furnaces have a smaller carbon footprint as they use more of the produced heating energy to heat the home and less heat leaves through the flue. However, when we consider the externalized carbon footprint from higher upfront cost, maintenance, repairs, etc., the carbon footprint argument may not hold. In Southern California, we usually recommend an 80% efficient furnace to strike a good balance between total cost & efficiency.  High-efficiency systems often qualify for significant rebates, which can make them attractive. For a ‘greener’ alternative, consider a heat pump system.  Call Haven Air Conditioning at (714) 332 – 6302 to get more information on the best heating system for your home.