Choosing the right insulation for your home is a crucial decision impacting energy efficiency, comfort, and your wallet. Two popular options are blown cellulose and fiberglass insulation. Both effectively reduce heat transfer, but they differ significantly in their composition, installation, and performance characteristics. This comprehensive guide will help you understand the key differences and determine which insulation best suits your needs.
What is Blown Cellulose Insulation?
Blown cellulose insulation is a loose-fill insulation made from recycled paper, often including treated wood fibers and borates for fire resistance and pest deterrence. It's installed using specialized equipment that blows the material into wall cavities, attics, and crawl spaces. Its fluffy nature allows it to settle comfortably, filling even the smallest gaps and crevices for superior air sealing.
What is Fiberglass Insulation?
Fiberglass insulation comes in various forms, including batts, rolls, and blown-in loose-fill. It's made from glass fibers bound together with a resin. While effective, fiberglass lacks the air-sealing properties of cellulose and can leave gaps if not installed precisely. Blown fiberglass shares some similarities with blown cellulose in installation method but differs significantly in material composition and thermal performance.
Blown Cellulose vs. Fiberglass: A Detailed Comparison
Here's a breakdown of the key differences between blown cellulose and fiberglass insulation:
R-Value:
- Cellulose: Offers a high R-value per inch, typically around R-3.7 to R-3.8 per inch. The actual R-value achieved can vary depending on the density of the installed material.
- Fiberglass: Provides a slightly lower R-value per inch, generally around R-3.1 to R-3.8 per inch, again depending on density. Higher density fiberglass batts offer better R-values.
Cost:
- Cellulose: Often more affordable upfront than fiberglass, especially considering its superior air-sealing properties. The long-term energy savings can further enhance its cost-effectiveness.
- Fiberglass: Generally slightly more expensive than cellulose, although price differences can vary depending on the region and supplier.
Installation:
- Cellulose: Requires specialized equipment and trained installers for proper application to achieve optimal density and air sealing.
- Fiberglass: Batts and rolls are relatively easy for DIY installation, although blown-in fiberglass also needs professional equipment and expertise.
Environmental Impact:
- Cellulose: An environmentally friendly option made from recycled materials, reducing landfill waste and lowering the carbon footprint compared to fiberglass.
- Fiberglass: Has a higher embodied energy (energy used in manufacturing) and relies on non-renewable resources. Disposal can also be more challenging.
Moisture Resistance:
- Cellulose: Generally more resistant to moisture absorption compared to fiberglass, which can absorb moisture, potentially leading to mold growth if not properly installed and protected from water intrusion.
- Fiberglass: More susceptible to moisture absorption, potentially impacting its insulating performance and creating conditions for mold growth.
Fire Resistance:
- Cellulose: Treated with borates to achieve fire resistance, meeting or exceeding building codes.
- Fiberglass: Considered inherently fire-resistant but does not require any additional treatments for fire resistance.
Pest Resistance:
- Cellulose: The borate treatment also makes it less attractive to pests like rodents and insects.
- Fiberglass: Not inherently pest-resistant and might require additional pest control measures.
Air Sealing:
- Cellulose: Superior air sealing capabilities due to its ability to fill small gaps and crevices.
- Fiberglass: Offers less effective air sealing, potentially leading to higher energy costs due to air leakage.
What are the benefits of blown-in cellulose insulation?
Blown-in cellulose insulation is lauded for its cost-effectiveness, excellent R-value, and superior air-sealing capabilities. Its environmentally friendly nature is also a significant advantage for environmentally conscious homeowners.
What are the benefits of blown-in fiberglass insulation?
Blown-in fiberglass insulation offers decent R-value, and its relative ease of installation (when compared to batt insulation) makes it a viable option in certain situations. It can also be a good choice in areas with limited access.
Which insulation is better for the attic?
Both cellulose and fiberglass can be effective in attics. However, cellulose's superior air sealing makes it a particularly attractive choice for attic insulation, reducing heat loss and energy costs.
Which insulation is better for walls?
The best choice for wall insulation depends on the existing wall structure and accessibility. Cellulose's ability to fill gaps makes it effective even in older homes with uneven wall cavities.
Conclusion: Making the Right Choice
The best insulation for your home depends on several factors, including your budget, environmental concerns, the structure of your home, and accessibility for installation. While both blown cellulose and fiberglass offer effective insulation, cellulose often emerges as the more cost-effective and environmentally friendly choice, particularly due to its superior air-sealing qualities. Consulting with a qualified insulation contractor is always recommended to assess your specific needs and determine the optimal solution for your home.
