Green Build & Design recently published an article that explains how SANCTUARY® by Greenfiber differs from other forms of insulation in that the raw product, trees, creates a carbon sink. The article continues by exploring SANCTUARY's competitive and superior insulation properties, such as blocking sound, odor and fire. Check out an excerpt of the article below and read the full version here. 

"At this point in the journey to make buildings more sustainable, one truism is fairly well understood. Before investing in renewable energy systems, energy-efficient windows, programmable thermostats, recycled steel, sustainable wood, and energy-efficient lighting, one feature is essential—a tight building envelope with high-performing insulation.

Most of the traditional materials—fiberglass, mineral wool, polyurethane-spray foam, polystyrene foam board, and polyisocyanurate—found in insulation require the extraction and use of fossil-based ingredients. Even worse, the manufacturing processes for these materials have a high carbon footprint. A study of 503 newly built homes in the Toronto region found that insulation is the second largest source (second to concrete) of material-related carbon emissions. More than 25% of the buildings’ embodied carbon was in those homes’ insulation materials.

One insulation material stands apart from the others, though, and that is cellulose."

Why Cellulose?

One reason cellulose insulation differs is that cellulosic material is plant-derived, typically from trees. That means the original source of these materials captures atmospheric carbon over the years before the trees are harvested. Even better, cellulose-based insulation is largely derived from post-consumer recycled paper, which is made from those trees.

A tree otherwise left to rot or burn would return the carbon to the environment, but when processed into paper and later building insulation, it continues to hold that carbon for at least the life of the structure.

The second reason cellulose insulation carries less embodied energy is that the manufacturing process of turning this recycled paper into building insulation itself has a low carbon footprint.

According to a study conducted in 2022 by the Builders for Climate Action—using BEAM (Building Emissions Accounting for Materials) software—11 types of cavity fill insulation products were measured for their Global Warming Potential, or GWP, all with R-10 insulation values applied over 100 square feet. The types ranged from closed cell polyurethane spray foam HFC (with the highest GWP) to cellulose dense packed (the lowest GWP). The second and third lowest-GWP ratings were cellulose dense packed and cellulose loose fill, respectively. The two highest performing products are manufactured by Greenfiber, all of which benefit from biogenic carbon storage because those products derive from trees, not petroleum.

Other types of insulation that had poorer GWP performance than cellulose fibers were mineral wool batt, mineral wool loose fill, fiberglass loose fill, fiberglass batt, and hemp wool batt.

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