Suisun City, CA: the heat pump payback math
In Suisun City, the math is close enough that it comes down to how long you plan to stay. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $1,000 after a $2,000 federal tax credit. Lower bills claw that back: about $78 saved annually, for a payback of roughly 12.9 years. Whether that's worth it in Suisun City depends on how many years you expect to own the place.
Why Suisun City's climate drives this number
Degree days tell the story here: Suisun City racks up 2372 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1044 cooling degree days on the cooling side. Sizing runs off the design temperature, not the average day: 33.3°F here (record low 30.2°F), which works out to a seasonal COP of 3.19 for the standard class of unit this climate calls for. A standard ducted system is enough here; Suisun City's design temperature doesn't justify the cold-climate premium. Climate figures trace to the nearest NOAA station, SAN FRANCISCO BAY RESERVE, 2.2 miles from Suisun City.
The month-to-month numbers for Suisun City
A 2000-square-foot house here would pull roughly 1,883 heating kilowatt-hours annually on top of cooling, totalling about $910 a year on electricity. Suisun City's gas rate of 22.01 per Mcf, applied to the 25 Mcf a year the furnace burns, puts its running cost near $988 a year, against 32.83¢ per kWh for electricity. Buy it outright, not incrementally, and payback stretches to 141.8 years; over 15 years the net position sits $163 ahead.
The other scenario: no gas furnace to begin with
Plenty of homes in Suisun City heat with electricity alone, no gas line involved. Against electric-resistance heat — baseboard or an electric furnace, both 100% efficient but still just resistance — the case for switching gets stronger here. About $1,506 a year comes back this way, enough that the 3.7-year payback clears the $5,500 premium comfortably within the equipment's life.
How Suisun City compares nationally
Suisun City lands at position 2243 out of 3206 cities on heating severity (coldest is 1), and 1365 out of 3206 by population size (biggest is 1). That's the mildest third of cities covered, where utility rates carry more of the answer than climate does.
What to do with this number in Suisun City
About 29,614 people live in Suisun City, California, and every number on this page is what a contractor would actually work from when quoting a system here — the point isn't to replace that quote, it's to tell you whether to bother asking for one. Here, there's no cost penalty to waiting until your current furnace or AC actually needs replacing.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
Nothing above is a black box: the methodology guide shows the full arithmetic behind Suisun City's 3.19 seasonal COP and payback figure. Not every home in Suisun City has gas; the guide comparing a heat pump against electric baseboard covers that case separately.