Should San Marino switch to a heat pump?
San Marino clears a genuine payback here, inside a reasonable stretch of years. $1,000 is what San Marino would pay extra to go electric rather than replace the furnace and AC with the same again, once the $2,000 federal credit is applied. Lower bills claw that back: about $323 saved annually, for a payback of roughly 3.1 years. That's a real payback, built from San Marino's own climate and utility rates, not a national guess.
The climate behind San Marino's payback figure
686 heating degree days pile up here every year, so San Marino barely has a winter to speak of; the cooling side runs to 2300 cooling degree days, where summers are hot enough that cooling matters as much as heating. Sizing runs off the design temperature, not the average day: 39.2°F here (record low 37.4°F), which works out to a seasonal COP of 3.37 for the standard class of unit this climate calls for. A standard ducted system is enough here; San Marino's design temperature doesn't justify the cold-climate premium. These numbers come from EL MONTE AIRPORT, the closest NOAA station, 5.3 miles out.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 515 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $813 a year. The gas furnace it replaces burns roughly 7 Mcf a year at 22.01 per Mcf here, for a running cost near $1,136 a year (electricity here runs 32.83¢/kWh). Looked at as a full purchase rather than an incremental one, payback here is roughly 34.1 years, leaving the 15-year total $3,842 ahead.
The other scenario: no gas furnace to begin with
Plenty of homes in San Marino 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. The saving here runs about $736 a year, which recovers the extra $5,500 spent going electric in roughly 7.5 years.
Where San Marino ranks in this dataset
Among 3206 cities, San Marino's winter puts it at rank 3012 for severity, while its size puts it at rank 2798 for population — 1 in both cases being the extreme. That's the mildest third of cities covered, where utility rates carry more of the answer than climate does.
Next step for 12,105 people in San Marino
About 12,105 people live in San Marino, 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, it's worth getting quotes before your current system fails, not after.
Get quotes from local HVAC contractors before deciding.
Reading further on this page's numbers
Every constant behind this page — the 3.37 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. See what San Marino's figure looks like without the $2,000 federal credit in the guide to how that credit moves the payback window.