Juana Díaz Municipio, PR Insulation Payback
Juana Díaz Municipio attic insulation, by the numbers
Juana Díaz Municipio, Puerto Rico is zone 1 under DOE's climate map (Hot-Humid), which means long, muggy summers and mild winters, where cooling dominates the energy bill. An uninsulated attic there should be built up to R-30. Going from R-2 to the recommended R-30 costs roughly $1,680 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 2.3 years at an estimated $729/year saved. Topping up the attic pays for itself fast here.
Where the savings come from
Split it out and it's roughly $0 a year on the heating side, $729 on cooling. By estimated insulation savings, Juana Díaz Municipio lands in the 3th percentile nationally. Zone 1 alone covers 81 counties in this dataset, and Juana Díaz Municipio comes in 34th by savings. Puerto Rico averages $660/year across the counties tracked here; Juana Díaz Municipio comes in 10% higher.
The climate data behind this
The heating and cooling degree days behind this estimate — 0 HDD and 4,700 CDD (base 65°F, 1991-2020 normals) — come from PONCE 4 E, PR RQ, the nearest NOAA station with published normals, 3 miles from Juana Díaz Municipio's center. Combined heating and cooling load puts Juana Díaz Municipio in the 17th percentile of this 3,162-county dataset. One local detail the R-value alone won't tell you: Juana Díaz Municipio sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
A shallower starting point changes the math: with R-11 already down, only the gap to R-25 needs filling, at roughly $840 for an estimated $80/year saved (~10.6-year payback). Call this borderline rather than a clear win.
Quotes and materials for this job
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 Juana Díaz Municipio's estimated $729/year on the line.
Where these figures come from
Juana Díaz Municipio's R-30 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-30 is the target here specifically.