Cellulose Insulation

Insulating with recycled paper

Cellulose Timeline

• Became commercially available 1940s

• Became popular during 1970s – Concerns about fire retardant properties– Questionable r-value claims

• Now accounts for about 10% of insulation market (CIMA)

• “Alternative” but gaining popularity

Why Cellulose?

• In 2008, paper = 31% of the municipal waste stream in U.S.

epa.gov

Composition• 75-85% recycled paper content (phone books, shipping boxes,

newspapers, etc.)• Remaining 15-25% composed of natural fire retardants boric acid

and/or ammonium sulfate.

http://insulation.sustainablesources.com/

Production

– VIDEO:http://www.youtube.com/watch?

v=6FWOwvthj34

Boric Acid Fire Retardant• Powdered boric acid added to cellulose

5% by weight

• Prevents flaming and smoldering

• Concerns about losing effectiveness

• 300 yrs for fire retardant to be effected

Installation Methods

1. Loose Fill- Dry cellulose blown into small holes in preexisting walls. - Ideal for retrofitting old homes where drywall is already in place.- Works well in attics, where gravity can hold the insulation in place. - Settles ~20%.

http://www.hgtvpro.com/hpro/bp_insulation/article/0,2617,HPRO_20150_4243847,00.html

• 2. Wet-Spray- Ideal for newly built walls.- Very little settling. - Natural adhesive properties from water.- Includes a bit of chlorine (concern to some). - Excess buildup is trimmed down to proper thickness prior to drywall installation.

http://insulation.sustainablesources.com/

Potential Hazards• Dust during installation

– Wear mask - boric acid can irritate mucous membranes– Wet installation

• Indoor Air Quality– Concerns have not been quantified

Drawbacks

• Absorbs water, should not be installed near leaking pipes.

• If treated with ammonium sulfate in addition to boric acid, can corrode metal if wet.

• Settling effect of loose-fill.

Cellulose vs. Fiberglass

• Often compared as equivalents. • University of Colorado study found:– Cellulose R-Value 3.6-4.0/inch– Fiberglas R-Value 3.0-4.0/inch– Cellulose found to pack together tighter in cavities, allowing less air exchange.

– 36-38% insulating outperformance.