Carroll County, MS Insulation Payback
Carroll County attic insulation, by the numbers
Carroll County, Mississippi is zone 3 under DOE's climate map (Mixed-Humid), which means a genuine mix of cold winters and humid summers, with neither one dominating the bill. An uninsulated attic there should be built up to R-49. For an attic around 1,000 square feet, closing the gap from R-2 to R-49 costs around $2,820 and saves an estimated $1,040 a year — payback in roughly 2.7 years. Topping up the attic pays for itself fast here.
Heating vs. cooling in Carroll County
Split it out and it's roughly $683 a year on the heating side, $357 on cooling. By estimated insulation savings, Carroll County lands in the 20th percentile nationally. Zone 3 alone covers 690 counties in this dataset, and Carroll County comes in 384th by savings. Mississippi averages $1,022/year across the counties tracked here; Carroll County comes in 2% higher.
The climate data behind this
The heating and cooling degree days behind this estimate — 2,573 HDD and 2,243 CDD (base 65°F, 1991-2020 normals) — come from GREENWOOD LEFLORE AP, MS US, the nearest NOAA station with published normals, 10.4 miles from Carroll County's center. That combined heating-and-cooling load ranks Carroll County 2528th nationally by total degree days — the 20th percentile. One local detail the R-value alone won't tell you: Carroll County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
A shallower starting point changes the math: with R-11 already down, only the gap to R-38 needs filling, at roughly $1,620 for an estimated $140/year saved (~11.6-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $2,820 as a starting estimate for a Carroll County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Carroll County's R-49 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-49 is the target here specifically.