Will a heat pump pay off in Mountain Brook, AL?
Mountain Brook sits right on the fence — how long you'll own the house decides this one. 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). Mountain Brook's residents would see roughly $277 a year back in running costs, putting the payback around 12.6 years. It's a genuine toss-up here — Mountain Brook's numbers don't point clearly either way.
Mountain Brook's weather, in the numbers that matter
2068 heating degree days pile up here every year, so Mountain Brook has a mild winter by US standards; the cooling side runs to 2428 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: 17.1°F here (record low 10°F), which works out to a seasonal COP of 3.11 for the cold-climate class of unit this climate calls for. Below the 25°F line where a standard machine starts leaning on resistance backup, Mountain Brook sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station BIRMINGHAM INTERNATIONAL AIRP, 5.2 miles from Mountain Brook — 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 1,684 kWh a year to keep it warm, plus cooling, for a combined electric bill near $624 a year. Mountain Brook's gas rate of 17.56 per Mcf, applied to the 22 Mcf a year the furnace burns, puts its running cost near $901 a year, against 16.62¢ per kWh for electricity. Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs about 48.7 years, for a 15-year net position $659 ahead.
The other scenario: no gas furnace to begin with
Gas isn't universal in Mountain Brook — many houses run on electric heat already. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. Switching saves about $769 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 10.4 years.
Where Mountain Brook ranks in this dataset
Ranked against the other 3206 cities covered, Mountain Brook comes in at 2407 for heating severity — 1 would be the coldest place in the dataset — and 1803 by population, where 1 is largest. 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 Mountain Brook
Mountain Brook, Alabama is home to about 21,701 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 Mountain Brook, 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
Every constant behind this page — the 3.11 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. At a 17.1°F design temperature, Mountain Brook sits in cold-climate territory; the guide to that class of unit explains why.