At a density of 151 bags/cubic ft we found an approximate R value of 9.43. Unfortunately we were not able to prove our hypothesis of reaching an R 13 value at this density. However we believe that alternate densities and alterations in bag consistency (shredding, foaming etc.) could reach a higher R value. This study did give us hope for an alternate use for an item that is often simply discarded. With further testing and refinements, post-consumer grocery bags could some day find themselves not on the side of a road, but in your walls. Architect Shigeru Ban has demonstrated a promising future of this material in his well-known ‘Naked House’. His design strategy utilized walls filled with “clear plastic bags, carefully stuffed with strings of foamed polyethylene for insulation purpose.” (Shigeru Ban) Were we to repeat this study, we believe that the use of a thermal heat flux transducer would yield a more accurate R-value for our material. Also, alterations to the hot box, including a better heat baffle, and a heat source with a more equal distribution method would improve results. We would also engage in longer tests to ensure more consistency and more tests to develop accuracy.
Conclusion
Interior of Naked House