Low GWP Spray Foam Expansion Agents: Why Performance also Matters

摘要

The spray polyurethane foam industry is transitioning from foam expansion agents (FEA) with high global warming potential (GWP) to low GWP alternatives. However, having a low GWP is not the sole criterion for a FEA to minimize climate change potential of spray foam insulation. Historic FEAs with high GWP, HCFC-141b and HFC-245fa, were evaluated along with a low-GWP FEA option from DuPont, HFO-1336mzz-Z with similar thermal conductivity. In addition, an open cell spray foam using water/ CO_2 as the blowing agent was compared which has a low GWP, but higher thermal conductivity. A holistic approach using life cycle methodology was used to calculate climate change potential across the entire supply chain, including raw material and spray foam production, spray foam installation, energy savings during product use, and end-of life (EOL) disposal. A residential wall application was evaluated under two different installation scenarios. When insulation R-value can be kept constant across insulation options, the GWP of the FEA is key to achieving low product system climate change potential. When insulation thickness is restricted, FEA thermal performance also becomes critical to minimizing overall climate change potential.