A heat pump's marketing focuses on efficiency ratings, SEER2 and HSPF2, as if a higher number automatically means a better purchase. Efficiency is one input into a real decision that also depends on your specific fuel costs, your climate, and how you plan to handle the coldest days of the year.
The core comparison: heat pump versus gas furnace
This decision comes down to your electricity rate, your gas rate, and the heat pump's coefficient of performance at your typical winter temperatures. The heat pump versus gas furnace engine runs that comparison directly on your entered rates rather than a generic regional average, which is where most rule-of-thumb advice falls apart.
Replacing versus converting
If your existing AC and furnace are both near end of life, the heat pump vs. AC/furnace replacement engine compares a heat pump against simply replacing both existing systems in kind. If you have a working furnace and are considering adding a heat pump alongside it, the gas-to-heat-pump conversion engine is the more relevant tool.
The dual-fuel middle path
Dual fuel is not a compromise so much as a distinct strategy: run the heat pump for efficiency most of the year, switch to gas below a set outdoor temperature where the heat pump's performance degrades. The heat pump versus dual-fuel engine finds where that switchover temperature should sit given your specific rates and equipment.
Cold-climate equipment is a separate cost decision
A cold-climate-rated heat pump costs more upfront in exchange for maintaining more of its capacity at low temperatures. Whether that premium is worth paying depends on how cold your actual design temperature gets and how much you would otherwise rely on expensive backup heat; see the cold-climate premium payback engine for that specific tradeoff.
Upgrading efficiency on an existing heat pump
If you already have a heat pump and are considering an efficiency upgrade rather than a fuel switch, the heat pump efficiency upgrade payback engine isolates that narrower question: is the incremental cost of a higher-efficiency unit worth it against your current one's remaining life.
Why the "right" answer varies by household
Two homes on the same street can reach opposite conclusions if one has a time-of-use electricity rate that makes daytime heating cheap and the other does not, or if one plans to keep the home for five years and the other for twenty. Treat every heat-pump recommendation you read elsewhere as a starting hypothesis, and confirm it against your own rates before committing.
Frequently asked questions
Is a heat pump always cheaper to run than a gas furnace?
No, it depends on your specific electricity and gas rates, and how efficiently the heat pump performs at your winter design temperature. Where electricity is expensive relative to gas, a furnace can win on operating cost even though a heat pump is more efficient in raw energy terms.
Do I need a backup heat source with a heat pump?
Standard heat pumps lose capacity in very cold weather and are commonly paired with backup heat, electric resistance or a dual-fuel furnace. A cold-climate-rated heat pump reduces but does not always eliminate that need; check your unit's rated capacity at your design temperature.
What is dual fuel and when does it make sense?
A dual-fuel system pairs a heat pump with a gas furnace as backup, switching to gas below a set outdoor temperature. It suits climates cold enough that a heat pump alone struggles, while still capturing most of the heat pump's efficiency during milder weather. Run the dual-fuel comparison engine to see where that crossover point actually pencils out for your rates.