Humphreys County, TN Insulation Payback
Humphreys County attic insulation, by the numbers
DOE classifies Humphreys County as climate zone 4, mixed-humid — real heating and real cooling seasons both, roughly balanced across the year. Its recommended attic R-value for bare joists is R-60. For an attic around 1,000 square feet, closing the gap from R-2 to R-60 costs around $3,480 and saves an estimated $1,245 a year — payback in roughly 2.8 years. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $997 a year on the heating side, $248 on cooling. By estimated insulation savings, Humphreys County lands in the 34th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Humphreys County comes in 694th by savings. Tennessee averages $1,258/year across the counties tracked here; Humphreys County comes in 1% lower.
Humphreys County's actual weather, not a national average
Humphreys County's climate figures — 3,729 heating and 1,544 cooling degree days a year — are read from WAVERLY AP, TN US, 5.7 miles away, NOAA's nearest 1991-2020 normals station. Combined heating and cooling load puts Humphreys County in the 33th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Humphreys County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $182/year saved — roughly 12.6 years to break even. Call this borderline rather than a clear win.
Getting it done in Humphreys County
Get more than one quote before committing. Attic access and any needed air sealing move the price around, and most contractors won't take a job below roughly $600 regardless of size - worth asking upfront given Humphreys County's estimated $1,245/year on the line.
Where these figures come from
Humphreys County's R-60 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-60 is the target here specifically.