Cellulose vs. Fiberglass The following is a summary of an extensive Natural Resources Defense Council (NRDC) report. The NRDC is a non-profit environmental membership organization with over 300,000 members and contributors nationwide:
The NRDC Has Concluded The Following:
Cellulose insulation manufactured from recycled paper is the least polluting and most energy efficient insulation. Cellulose has the highest post-consumer recycled content. The fiberglass industry averages 35% recycled glass, while the cellulose industry averages a minimum of 75% recycled content.
It takes more than 10 times as much energy to produce fiberglass insulation as cellulose insulation. Due to air circulation and natural convection, the R-value of blown-in fiberglass insulation decreases by as much as 50% as the temperature drops from 45 degrees F to 18 degrees F.
Cellulose has better resistance to air flow and prevents the upward movement of air caused by temperature differences (the R-value of cellulose actually improves during cold weather).
Substantial and well-documented public health threats are associated with fiberglass.
No adverse health effects from cellulose insulation have been identified. Cellulose is non-toxic. Biologically, cellulose is innocuous. ~ Dr. Arthur Furst, Toxicologist
Notice in this picture of the inside of a wall insulated by both cellulose and fiberglass… the plumbing is not visible in the cellulose and the insulation fills the entire wall cavity, as insulation should – leaving no gaps or voids that would allow for air movement and energy loss.