Sherman, TX: the heat pump payback math
In Sherman, the math is close enough that it comes down to how long you plan to stay. 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). Sherman's residents would see roughly $348 a year back in running costs, putting the payback around 10.1 years. It's a genuine toss-up here — Sherman's numbers don't point clearly either way.
Sherman's weather, in the numbers that matter
Sherman has a mild winter by US standards — 2068 heating degree days a year against a 65°F base — and summers are severe enough that cooling can dominate the annual bill, at 2893 cooling degree days. Sizing runs off the design temperature, not the average day: 14.4°F here (record low 8.6°F), which works out to a seasonal COP of 3.05 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Sherman — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Source: NOAA station GRAYSON COUNTY AIRPORT, 6.5 miles from Sherman — the closest one on record.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 1,717 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $676 a year. That compares with roughly 22 Mcf a year of gas at Sherman's 19.42 per-Mcf rate — about $1,024 a year — against a local electricity rate of 16.15¢/kWh. Looked at as a full purchase rather than an incremental one, payback here is roughly 38.8 years, leaving the 15-year total $1,722 ahead.
Electric resistance heat in Sherman, compared
Not every home in Sherman has gas service. Swap the comparison to resistance heat instead of gas, and Sherman's answer improves. The saving here runs about $776 a year, which recovers the extra $8,000 spent going electric in roughly 10.3 years.
How Sherman compares nationally
Ranked against the other 3206 cities covered, Sherman comes in at 2402 for heating severity — 1 would be the coldest place in the dataset — and 814 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 50,229 people in Sherman
Sherman, Texas is home to about 50,229 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 Sherman, 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
Nothing above is a black box: the methodology guide shows the full arithmetic behind Sherman's 3.05 seasonal COP and payback figure. Sherman's 14.4°F design temperature is below the 25°F line, which is why a cold-climate unit is the right call here — see what that changes in the cold-climate unit guide.