Case study library · 6 cases
Six climates. Six honest answers.
Every calculator on this site runs on the same energy model — degree days, seasonal COP, real electricity and fuel rates. Here's what that model says for six real households in six different climates, replacing five different baseline systems. Heat pumps win three of these. They lose two. One is close enough to call a toss-up.
Cold-Climate Heat Pump vs. Gas Furnace
Gas furnace saves $13,756 over 10 years
A Bungalow Belt three-flat weighs a cold-climate heat pump against its existing gas furnace. ComEd's residential rate — nearly 24¢/kWh — erases the efficiency advantage a cold-climate unit would otherwise deliver against cheap Illinois natural gas.
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Cold-Climate Heat Pump vs. Oil Furnace
Oil furnace saves $347 over 10 years
Minnesota's harshest-in-the-Lower-48 degree days push even a NEEP-listed cold-climate unit's seasonal COP down near 2.0. Against aging oil-furnace economics, the two systems land within a rounding error of each other over a decade.
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Standard Heat Pump vs. Electric Resistance
Heat pump saves $12,353 over 10 years
A 1990s ranch heated by electric-resistance strips is the easiest case on this site. Georgia's mild winters mean a standard heat pump barely needs backup heat, and COP-of-1 resistance heating never had a chance against it.
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Cold-Climate Ductless Mini-Split vs. Oil Furnace
Oil furnace saves $5,488 over 10 years
A three-zone ductless retrofit for a Boston triple-decker unit runs into New England's highest-in-the-continental-US electricity rate — nearly 29¢/kWh. Even a cold-climate mini-split's efficiency can't out-earn that against oil heat.
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Standard Heat Pump vs. Electric Furnace + AC
Heat pump saves $7,407 over 10 years
Phoenix barely heats at all — this case is really about cooling. A heat pump's SEER2 cooling advantage over an aging electric-furnace-and-AC combo does almost all the work, with heating costs nearly irrelevant to the outcome.
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Ductless Mini-Split vs. Electric Baseboard
Heat pump saves $7,774 over 10 years
A postwar bungalow with electric baseboard heat is a textbook Pacific Northwest retrofit. Seattle's mild winters and cheap hydro-heavy electricity mean a two-zone ductless system pays for itself almost entirely on the heating side.
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Every figure in these case studies was generated with the same degree-day energy model that powers the Heat Pump Cost and Heat Pump vs. Traditional HVAC calculators, using representative home sizes, equipment sizing, and each state's actual EIA-reported electricity and fuel prices at the time of writing. Your specific home, contractor quote, and utility rate plan will differ. See the methodology page for the full model and sourcing.