Heat Pump Payback in San Dimas, CA
Will a heat pump pay off in San Dimas, CA?
This one's marginal in San Dimas: it only clears if you stay long enough. $3,000 is what San Dimas would pay extra to go electric rather than replace the furnace and AC with the same again. Lower bills claw that back: about $251 saved annually, for a payback of roughly 12 years. Whether that's worth it in San Dimas depends on how many years you expect to own the place.
Not the city you meant?
This runs the same numbers for 3206 US cities, not just San Dimas. Look one up here.
Why San Dimas's climate drives this number
San Dimas barely has a winter to speak of, 1219 heating degree days a year against a 65°F base, and summers are hot enough that cooling matters as much as heating, at 1906 cooling degree days. 37.4°F is the figure equipment gets sized against here, the 99th-percentile cold snap, not an average day, with a low of 35.6°F in the 2024 station record. Worked through the model, that's a seasonal COP of 3.31 on the standard unit fit for this climate. A standard ducted system is enough here; San Dimas's design temperature doesn't justify the cold-climate premium. Source: NOAA station Brackett Field Airport, 1.6 miles from San Dimas, the closest one on record.
The yearly running costs in San Dimas
Modelled on a typical 2000-square-foot house, the heat pump draws about 933 kWh a year to keep it warm, plus cooling, for a combined electric bill near $840 a year. That compares with roughly 13 Mcf a year of gas at San Dimas's $22.01 per-Mcf rate, about $1,090 a year with the old AC included, against a local electricity rate of 32.83¢/kWh. Priced as a standalone purchase, with a working furnace ripped out early, payback would take longer than the 15-year equipment life. Measured against the like-for-like replacement instead, a household here ends 15 years $761 ahead.
The break-even point in San Dimas
This result holds unless electricity climbs above 319.5¢/kWh (it is 32.83¢ now) or gas drops below $2.26 per Mcf (now $22.01); past either point, gas becomes the cheaper fuel in San Dimas. When quotes arrive, compare the heat pump price with a like-for-like furnace and AC replacement: at $251 a year saved, a difference under $1,757 pays back within 7 years here, and under $2,510 within 10.
The other scenario: no gas furnace to begin with
Not every home in San Dimas has gas service. Against electric-resistance heat, baseboard or an electric furnace, both 100% efficient but still just resistance, the case for switching gets stronger here. The saving here runs about $985 a year, which recovers the extra $7,500 spent going electric in roughly 7.6 years.
How San Dimas compares nationally
San Dimas lands at position 2792 out of 3206 cities on heating severity (coldest is 1), and 1237 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 San Dimas
About 33,226 people live in San Dimas, 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 San Dimas's 3.31 seasonal COP and payback figure. Not every home in San Dimas has gas; the guide comparing a heat pump against electric baseboard covers that case separately.