Assessing the Global Warming Potential (GWP) of Blowing Agents

By Cass Jacoby. 

Choose greener products by looking at the manufacturing process of blowing agents. 

When it comes to choosing the products that will be used on your roof, an important consideration is the product’s environmental impacts. Assessing the global warming potential (GWP) of the blowing agents used to manufacture insulation products is a helpful way to tell how green a product is.  

GWP is a measure of a substance’s ability to trap heat in the atmosphere and is calculated over a specific period of time (commonly 100 years). Specifically, GWP measures how much energy the emissions of one ton of a gas will absorb over a given period of time, relative to the emissions of one ton of carbon dioxide.  A substance that traps more heat will contribute more to global warming (and will be assigned a higher GWP value). Therefore, products that incorporate low-GWP blowing agents provide insulation solutions that offer reduced environmental footprints. 

Blowing agents increase the final thermal resistance of foam insulation and facilitate the manufacturing process. Some manufacturers of laminated polyiso insulation products in North America use pentane or pentane blends in their production processes. Pentane is a hydrocarbon with zero ozone depletion potential (ODP) and low-GWP. In this article,  Polyiso Manufacturers Association (PIMA), explains that their manufacturers have utilized pentane technologies in product formulations for over 20 years. 
 
Pentane has a GWP value of less than 10, which means that polyiso insulation products produced and sold in North America comply with climate regulations that limit the manufacture or installation of products produced with higher-GWP substances (including products manufactured with hydrofluorocarbons (HFCs) or blends thereof).  

Choosing polyiso insulation products manufactured by PIMA members is a more environmentally friendly option that still delivers above the industry standard. 

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About Cass  

Cass works as a reporter/writer for RoofersCoffeeShop and AskARoofer. When she isn’t writing about roofs, she is writing about movies for her master's degree and dancing with her plants.