This study investigates the long-term thermal performance of polyurethane insulated cold storage panels and the environmental and economic impact of recycling such panels when taken out of service in lieu of discarding them in landfills.
It is estimated, as of 2015, over 180 million square feet of insulated cold storage panels are manufactured annually in the U.S. The panels are most frequently constructed of closed-cell, low density polyurethane insulation utilizing HCF 245fa and HCF 134a blowing agents containing up to 6 million metric tons (CO2e) of greenhouse gases. The expected operating lifetime of the cold storage panels is 15 years after which time they are primarily discarded in landfills. This practice contributes to the build-up of greenhouse gases in the atmosphere, destroys valuable insulating and building materials and requires landfill space for the solid waste.
Three recycling strategies were investigated as ways to repurpose the discarded framed cold storage panels into new forms of polyurethane insulating materials; repurposed cold storage panels, board stock insulation sheets and blown-in/fill insulation. I used three research methods to quantify the environmental and economic impacts. The first examined the initial and long-term thermal performance of the recycled polyurethane insulation through laboratory testing and extrapolative modeling. The second method was comparative life cycle assessments between the business-as-usual-case of discarding the polyurethane insulation with each of the recycled strategies. Finally, an economic analysis was completed for each recycling strategy to determine the in-use heating & cooling energy savings from the extended life of the recycled insulation.
This research shows recycling of discarded polyurethane cold storage panels provide measurable environmental and economic benefit. First, the productive life of the insulation is extended greatly beyond its initial use period reducing the need for fossil fuels and raw materials to make replacement insulations. Secondly, the high insulating value of the recycled polyurethane maximizes future environmental and economic savings from lower fuel demand in space heating and cooling applications. Thirdly, the majority of the sequestered greenhouse gases continue to be bound in the foam; protecting the environment from the release of global warming gases. Finally, by diverting the cold storage panels from landfills, millions of cubic feet of landfill space are unneeded annually.
| Identifer | oai:union.ndltd.org:harvard.edu/oai:dash.harvard.edu:1/24078364 |
| Date | 11 January 2016 |
| Creators | Costanza, James |
| Publisher | Harvard University |
| Source Sets | Harvard University |
| Detected Language | English |
| Type | Thesis or Dissertation, text |
| Format | application/pdf |
| Rights | open |
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