Why does Eco-Panels use polyurethane rather than polystyrene (EPS)?
Eco-Panels chose to use closed cell polyurethane foam insulation instead of expanded polystyrene (EPS) for several reasons. First, polyurethane is a far better insulator than EPS. Eco-Panels polyurethane foam has a nominal R-value of R-7 per inch of thickness, versus ~R-3.7 for EPS. This means that you can achieve R-26 with 4.5-inch walls. EPS-insulated walls would have to be nearly twice as thick to achieve the same R-value. Second, when polyurethane foam is injected into panels, the panels are structurally stronger than EPS panels. While the EPS is simply glued onto the substrates (with either water, polyurethane or formaldehyde based glues), injected polyurethane foam adheres and bonds to every surface (substrates, top-plates, splines, cam-locks, electrical boxes, etc.), and then becomes rigid. Third, polyurethane has better fire, flame, and smoke characteristics. Much more on fire and safety issues later but suffice it to say that our foam is significantly safer in a fire situation
