This section covers how heat pumps work, ductless mini-splits, dual-fuel systems and heat pump water heaters. It also covers thermostat settings, switching from oil heat, installed costs, federal rules, rebates and local guides for Texas, Columbus, Ohio, and western Washington.
ENERGY STAR says heat pumps move heat rather than converting it from fuel, as heat pump vs. furnace explains. Split-system heat pumps made on or after January 1, 2023 need at least 7.5 HSPF2 under federal rules. SEER2 is a seasonal cooling efficiency rating, and split heat pumps need 14.3 SEER2 everywhere under the federal rule. If you own an R-410A system, EPA says you can maintain and repair it for the rest of its useful life. DOE's 2022 Energy Saver Guide describes a setback of 7–10°F for 8 hours a day in fall and winter. If you have a heat pump, it says not to do this without a smart or programmable thermostat designed for heat pumps.
A ductless mini-split pairs an outdoor unit with one or more indoor heads, and refrigerant carries heat between them, ENERGY STAR says. A dual-fuel system pairs a heat pump with a gas or oil furnace, ENERGY STAR says, so you can heat with either one. Below the balance point, a heat pump cannot fully heat the home without backup, a DOE-funded guide says. We found no primary source that sets one switchover temperature for every home. DOE's 2022 Energy Saver Guide calls heat pumps an efficient option for homes with central propane or oil. A DOE-funded guide says a heat pump water heater pulls heat from the air around it and moves it into the tank. DOE set new water heater standards in a 2024 rule, and they must be met on and after May 6, 2029.
DOE's 2017 rule analysis averaged $4,686 to $4,806, in 2015 dollars, for a 3-ton split heat pump at 14 to 15 SEER. A 2023 study for EIA put a 3-ton blower-coil heat pump at $6,810 in 2022 dollars at its 2023 standard level. For one 12 kBtu/h ductless mini-split heat pump, a 2023 study for EIA estimated $2,030 installed, in 2022 dollars. The heat pump cost guide and the mini-split cost guide both note that these figures are federal modeling inputs, not 2026 price quotes. Public Law 119-21, dated July 4, 2025, ended the 25C tax credit for property placed in service after December 31, 2025. The IRS says you can claim it for improvements made through December 31, 2025, by filing Form 5695 with your tax return. Federal home energy rebates are separate, run through state programs and differ in status from state to state.
NOAA's 1991–2020 normals show Austin-Bergstrom averages 0.0 days a year with a low at or below 10°F. On February 16, 2021, the airport recorded a low of 6°F. NOAA's 1991–2020 normals show Columbus averages 10.1 days a year with a low at or below 10°F. NEEP and ENERGY STAR cold-climate criteria both set levels at 5°F. Whether a heat pump, a hybrid system or a gas furnace costs less to run depends on your own electric and gas rates.
