Heat Pump vs Furnace: Think TWICE Below 40°F

A heat pump stops being cheaper to run than a gas furnace at one outdoor temperature. At February 2026 national prices, it's about 40°F. A dual fuel kit instruction sheet from June 1998, still in Rheem's literature archive, worked the same question and landed on 30 degrees for its example. This February the national electric rate was two and a half times that example's rate and gas was a little over double, so the line has moved toward the furnace. This video rebuilds that math with EIA's February 2026 prices. Plain electric heat comes to $51.73 per million BTU and a 95% gas furnace to $15.18, so a heat pump needs a COP of 3.4 just to tie. Then it reads Mitsubishi's 2023 submittal sheet for the FS18NA Hyper-Heating wall unit at 47, 17 and 5 degrees, shows how one unit at one temperature runs anywhere from slightly cheaper than gas to about 55% more expensive depending on compressor speed, and gives you the formula to run with your own two bills. After that, two neighboring states where the answer flips. Idaho has the fourth-lowest residential electric rate in the country and still comes out gas. Washington, with pricier power, comes out heat pump at rated speed. It ends on the dual fuel changeover setting, called Compressor Min Outdoor Temperature on an ecobee, and why one co-op install guide's suggested 30 degrees sits ten degrees below the arithmetic. More on household systems and building physics: www.youtube.com/@TheMeasuredHouseYT Sources cited: U.S. Energy Information Administration, average residential electricity price by state, February 2026 and February 2025; residential natural gas price, U.S. and by state, February and July 2026; heat content of natural gas, 2025. Dual fuel kit instruction sheet, form 7077650, printed June 1998 (Rheem literature archive, files.rheem.com). Mitsubishi Electric Trane submittal sheet, FS18NA Hyper-Heating wall unit, 2023. NEEP Cold Climate Air Source Heat Pump Specification, Version 4.0. U.S. Department of Energy residential furnace efficiency standard and current litigation coverage (ACHR News, Contracting Business, ACCA, June 2026). ecobee user guide. Advanced Energy ecobee4 dual fuel install guide, hosted by Berkeley Electric Cooperative. ComEd Dual Fuel Switchover Guide. Nothing in this video is a specific recommendation for your house. New videos Tuesday, Thursday, Saturday and Sunday.