Heat pump vs. gas furnace in Smithfield, NC

This one's marginal in Smithfield: it only clears if you stay long enough. Against a like-for-like gas furnace and AC swap, going electric costs $3,500 more up front here (already netting out a $2,000 tax credit). That premium is recovered through $256 of lower running costs every year, landing the payback clock at roughly 13.6 years. It's a genuine toss-up here — Smithfield's numbers don't point clearly either way.

How cold Smithfield actually gets

2719 heating degree days pile up here every year, so Smithfield has a mild winter by US standards; the cooling side runs to 1688 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: 21.2°F here (record low 17.6°F), which works out to a seasonal COP of 3.21 for the cold-climate class of unit this climate calls for. Smithfield needs the cold-climate class of unit: past a 25°F design temperature a standard heat pump falls back on resistance backup often enough to eat the savings. Source: NOAA station JOHNSTON COUNTY AIRPORT, 2.4 miles from Smithfield — the closest one on record.

What it actually costs to run, year to year

Modelled on a typical 2000-square-foot house, the heat pump draws about 2,145 kWh a year to keep it warm, plus cooling, for a combined electric bill near $535 a year. The gas furnace it replaces burns roughly 28 Mcf a year at 16.42 per Mcf here, for a running cost near $792 a year (electricity here runs 14.93¢/kWh). Buy it outright, not incrementally, and payback stretches to 52.6 years; over 15 years the net position sits $347 ahead.

Electric resistance heat in Smithfield, compared

Not every home in Smithfield has gas service. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. Switching saves about $819 a year here — a heat pump moving heat rather than generating it needs far less electricity than resistance coils — so the extra $8,000 spent up front comes back in about 9.8 years.

Smithfield against the rest of the country

Smithfield lands at position 2029 out of 3206 cities on heating severity (coldest is 1), and 2680 out of 3206 by population size (biggest is 1). That's the middle third for winter severity among the cities covered here.

Next step for 12,806 people in Smithfield

Smithfield, North Carolina is home to about 12,806 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 Smithfield, nothing is lost by holding off until the current equipment genuinely fails.

Ask a local HVAC contractor for a quote before committing either way.

Reading further on this page's numbers

Every constant behind this page — the 3.21 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. At a 21.2°F design temperature, Smithfield sits in cold-climate territory; the guide to that class of unit explains why.