Quick Answer
Hemp insulation is generally more efficient than fiberglass, offering R-values of up to R-38 per inch compared to fiberglass's R-2.9 to R-3.8 per inch. Hemp insulation also provides better thermal mass and moisture resistance.
Thermal Performance
Hemp insulation’s higher R-value is due to its unique cellular structure, which traps air and reduces heat transfer. In contrast, fiberglass relies on the insulation’s thickness to achieve its R-value. To put this into perspective, a 6-inch thick hemp insulation panel can achieve an R-value of R-38, while a 6-inch thick fiberglass batt would only reach R-23. Additionally, hemp insulation’s thermal mass helps regulate indoor temperatures, reducing the need for heating and cooling.
Moisture Resistance and Durability
Hemp insulation also offers superior moisture resistance, as it is less susceptible to water damage and mold growth. This is due to hemp’s natural hydrophobic properties and its ability to absorb and release moisture without compromising its R-value. In contrast, fiberglass can become waterlogged and lose its insulating properties when exposed to moisture. Hemp insulation’s durability also makes it a more sustainable option, as it can last for decades with minimal maintenance.
Installation and Cost
While hemp insulation may be more expensive upfront, its long-term benefits and increased efficiency make it a more cost-effective option in the long run. Hemp insulation can be installed using a variety of methods, including spray-on and panelized systems. A typical installation cost for hemp insulation is around $3 to $5 per square foot, compared to $1 to $2 per square foot for fiberglass. However, the increased R-value and thermal mass of hemp insulation can lead to significant energy savings and reduced maintenance costs.
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