Round Rock, TX: the heat pump payback math
Round Rock sits right on the fence — how long you'll own the house decides this one. $3,500 is what Round Rock 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. Round Rock's residents would see roughly $342 a year back in running costs, putting the payback around 10.2 years. It's a genuine toss-up here — Round Rock's numbers don't point clearly either way.
Round Rock's weather, in the numbers that matter
Round Rock barely has a winter to speak of — 1359 heating degree days a year against a 65°F base — and summers are severe enough that cooling can dominate the annual bill, at 3391 cooling degree days. Sizing runs off the design temperature, not the average day: 19.4°F here (record low 12°F), which works out to a seasonal COP of 3.17 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, Round Rock sits firmly in cold-climate territory, so that's the class of unit priced here. These numbers come from GEORGETOWN MUNICIPAL ARPT, the closest NOAA station, 10.6 miles out.
The month-to-month numbers for Round Rock
A 2000-square-foot house here would pull roughly 1,086 heating kilowatt-hours annually on top of cooling, totalling about $642 a year on electricity. The gas furnace it replaces burns roughly 14 Mcf a year at 19.42 per Mcf here, for a running cost near $985 a year (electricity here runs 16.15¢/kWh). Looked at as a full purchase rather than an incremental one, payback here is roughly 39.4 years, leaving the 15-year total $1,635 ahead.
The other scenario: no gas furnace to begin with
Not every home in Round Rock has gas service. Swap the comparison to resistance heat instead of gas, and Round Rock's answer improves. About $623 a year comes back this way, enough that the 12.8-year payback clears the $8,000 premium comfortably within the equipment's life.
Round Rock against the rest of the country
Ranked against the other 3206 cities covered, Round Rock comes in at 2746 for heating severity — 1 would be the coldest place in the dataset — and 218 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.
Deciding what's next in Round Rock, TX
Round Rock, Texas is home to about 135,359 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 Round Rock, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
Nothing above is a black box: the methodology guide shows the full arithmetic behind Round Rock's 3.17 seasonal COP and payback figure. At a 19.4°F design temperature, Round Rock sits in cold-climate territory; the guide to that class of unit explains why.