Insulation Comparisons
| Type | R-value / Inch | Embodied Energy1 | Advantages | Disadvantages |
|---|---|---|---|---|
| Airkrete (Magnesium Silicate) | 3.9 | - | Non-flammable Fills cavities fully |
Expensive, Friable |
| Blown in blanket | 4.2 | - | Expensive | |
| Cellulose (dry) | 3.2 | 600 | Recycled | Can Settle |
| Cellulose (wet sprayed) | 3.5 | 600 | Recycled | Professionial install |
| Cotton | 3.0 - 3.7 | - | Recycled | Expensive |
| Fiberglass | 3.2 | 4,550 | Common | Most contain formaldehyde Needs careful installation |
| Fiberglass (rigid) | 4.4 | - | ||
| Icynene (Polyurethane) | 3.6 - 4.3 | - | Seals, No CFCs | Professional installation |
| Mineral Wool (batts) | 2.8 - 3.7 | - | ||
| Phenolic foam | 4.8 | - | Professional installation | |
| Polyisocyanurate | 5.6 - 7.7 | 14,300 | Expensive | |
| Polystyrene, expanded (EPS) | 3.6 - 4.4 | 18,000 | Expensive | |
| Polystyrene, extruded (XPS) | 5.0 | - | Underground applications | Expensive, HCFC-142b |
| Polyurethane (closed cell) | 5.8 - 6.8 | - | ||
| Straw | 1.5 | - | Cheap | Best in Strawbale buildings |
Footnotes:
- BTUs for R-20 over 1 square foot.