Which insulator works in a humid tropical climate, where to put it, and when it's not worth it. With the full materials comparison, no favorites.
In a hot, humid climate, the biggest return comes from insulating the roof and reducing solar radiation, more than from insulating walls. The best insulator isn't just the one with the lowest conductivity: you have to weigh moisture, fire, durability, cost, installation and availability.
Thermal conductivity (lower is better), fire reaction, moisture and acoustics. Data from technical sources and peer review See evidence.
| Material | λ (W/m·K) | Fire | Moisture | Acoustics |
|---|---|---|---|---|
| Rock wool | 0.033-0.041 | A1-A2 · non-combustible | Hydrophobic, dries and recovers R | Excellent (NRC ~1.0) |
| Glass wool | 0.030-0.050 | A1-A2 · non-combustible | Fibrous, moisture-sensitive | Good |
| EPS | 0.031-0.040 | E · combustible | Low-medium absorption | Poor |
| XPS | 0.032-0.037 | E · combustible | Very low absorption (0.2-0.7%) | Poor |
| PIR | 0.019-0.028 | B-s1,d0 · self-extinguishing | Absorption <2% | Poor |
| PUR / spray foam | 0.022-0.028 | Below PIR | Closed cell, low absorption | Poor |
| Cellulose | 0.037-0.042 | B-E · boron-treated | Hygroscopic (absorbs) | Very good |
Ranges vary by density and manufacturer. PIR/PUR achieves the thinnest profile for its conductivity; mineral wools win on fire and acoustics.
Every fibrous insulator loses performance when wet: 1% moisture in mineral wool reduces its performance by 5 to 10% See evidence. That's why, in Panama, installation details (ventilation, vapor control) matter as much as the material.
What's left is the specifics: which intervention makes sense for your home. Gallardía diagnoses and installs residential thermal solutions in Panama.
Every important claim links to its evidence. Tap to see the source, its context and its limits: Silva et al. Rock wool RES. Full bibliography in the evidence library.