South Fulton, GA: the heat pump payback math
This one's marginal in South Fulton: it only clears if you stay long enough. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $3,500 after a $2,000 federal tax credit. That premium is recovered through $339 of lower running costs every year, landing the payback clock at roughly 10.3 years. It's a genuine toss-up here — South Fulton's numbers don't point clearly either way.
How cold South Fulton actually gets
South Fulton has a mild winter by US standards — 2093 heating degree days a year against a 65°F base — and summers are hot enough that cooling matters as much as heating, at 2333 cooling degree days. 14°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of 12.9°F on file. Worked through the model, that's a seasonal COP of 3.04 on the cold-climate unit fit for this climate. South Fulton 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. These numbers come from HARTSFIELD-JACKSON ATLANTA IN, the closest NOAA station, 8.1 miles out.
The month-to-month numbers for South Fulton
A 2000-square-foot house here would pull roughly 1,743 heating kilowatt-hours annually on top of cooling, totalling about $556 a year on electricity. South Fulton's gas rate of 20.42 per Mcf, applied to the 22 Mcf a year the furnace burns, puts its running cost near $896 a year, against 14.90¢ per kWh for electricity. Buy it outright, not incrementally, and payback stretches to 39.8 years; over 15 years the net position sits $1,592 ahead.
Electric resistance heat in South Fulton, compared
Gas isn't universal in South Fulton — many houses run on electric heat already. Swap the comparison to resistance heat instead of gas, and South Fulton's answer improves. Switching saves about $684 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 11.7 years.
South Fulton against the rest of the country
Ranked against the other 3206 cities covered, South Fulton comes in at 2381 for heating severity — 1 would be the coldest place in the dataset — and 287 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.
Next step for 112,003 people in South Fulton
South Fulton, Georgia is home to about 112,003 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 South Fulton, nothing is lost by holding off until the current equipment genuinely fails.
Line up a few local HVAC quotes before you decide.
Where South Fulton's figure comes from
Every constant behind this page — the 3.04 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. South Fulton's 14°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.