Is a heat pump worth it in Napa?

Here in Napa, the honest answer is that a heat pump raises your annual running cost. $1,000 is what Napa 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. Unfortunately the electric bill outweighs the gas bill it replaces by about $77 a year here, so the extra spend stays unrecovered. That's Napa's own climate and rates talking, not a hedge or a caveat.

Napa's weather, in the numbers that matter

2823 heating degree days pile up here every year, so Napa has a mild winter by US standards; the cooling side runs to 291 cooling degree days, where summers rarely ask much of an air conditioner. Sizing runs off the design temperature, not the average day: 28.9°F here (record low 27°F), which works out to a seasonal COP of 3.06 for the standard class of unit this climate calls for. Napa's winters don't get cold enough to need the cold-climate premium — a standard unit holds up fine. These numbers come from NAPA COUNTY AIRPORT, the closest NOAA station, 6.1 miles out.

Napa's running-cost comparison, in dollars

Modelled on a typical 2000-square-foot house, the heat pump draws about 2,336 kWh a year to keep it warm, plus cooling, for a combined electric bill near $848 a year. The gas furnace it replaces burns roughly 29 Mcf a year at 22.01 per Mcf here, for a running cost near $771 a year (electricity here runs 32.83¢/kWh). Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs past the 15-year equipment life, for a 15-year net position $2,162 behind.

Electric resistance heat in Napa, compared

Plenty of homes in Napa 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. Switching saves about $1,622 a year here — a heat pump moving heat rather than generating it needs far less electricity than resistance coils — so the extra $5,500 spent up front comes back in about 3.4 years.

Napa against the rest of the country

Among 3206 cities, Napa's winter puts it at rank 1981 for severity, while its size puts it at rank 492 for population — 1 in both cases being the extreme. That's the middle third for winter severity among the cities covered here.

Deciding what's next in Napa, CA

Napa, California is home to about 76,921 people, and the figures above are the same ones a local HVAC contractor uses to size and quote a system — this site doesn't guess where a real quote would land, it just tells you whether it's worth asking for one. In Napa, nothing is lost by holding off until the current equipment genuinely fails.

Line up a few local HVAC quotes before you decide.

Reading further on this page's numbers

Nothing above is a black box: the methodology guide shows the full arithmetic behind Napa's 3.06 seasonal COP and payback figure. Napa is one of the cities where running costs land higher every year, not just slower to pay back — the guide to where this happens lays out why.