It depends on your climate, your rates, and whether you are willing to keep gas in the house. A dual-fuel (hybrid) replacement keeps a gas furnace, or installs a new one, and uses a heat pump as the first stage of heat, with a changeover to gas when it is colder or when the heat pump cannot keep up. A full-electric replacement removes the furnace and uses the heat pump for all heating, with electric resistance as backup if the design needs it. At 2025 EIA averages, many Midwestern and Northeastern states still show a lower unit cost of heat for a 95% furnace than for an 8.1 HSPF2 heat pump — Illinois is about 11.30 vs 21.81 per MMBtu in this site’s table — which is why dual fuel shows up in Chicago-suburbs threads. Texas, at these ratings, is a close call the other way.
Full electric is more compelling when a cold-climate unit is sized to design temperature, when your electricity is cheap or solar-backed, when the gas service has a high fixed charge you would like to drop, or when you are already electrifying the rest of the house. It is less compelling when the quote is a mild-climate heat pump plus a large strip kit on a 100-amp panel. Dual fuel keeps the flue and some gas bill, but it can shrink both the operating-cost risk and the panel problem.
Have the contractor show both options on the same Manual J and the same rate sketch, including the changeover idea on the dual-fuel page. Use the calculator with your bills, and put any backup strips on the panel calculator.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.