Safe Effective Affordable Retrofits

This project looked at retrofit options that could serve as an alternative for exterior foam board, using the Mobile Test Lab to evaluate several wall configurations for moisture performance.­ It found that vapor permeable exterior insulations offer an affordable alternative to foam retrofits. 

1. Our latest study of wall retrofits suggested that using cellulose as exterior insulation instead of foam board allowed for better moisture control within the wall. Because cellulose is more permeable to water vapor than foam, it is less likely to trap moisture in the wall. 

2. Another retrofit approach includes air sealing the wall sheathing by adding an air barrier without adding any exterior insulation. This wouldn't improve the R-value of the wall but would be less expensive than a full exterior insulation retrofit (such as the REMOTE wall) and would still save energy by reducing air leakage.

Both approaches avoid trapping moisture in the wall assembly while aiming to reduce the cost and complexity of retrofits. This project established more background on these approaches, including a literature review, modeling, and interviews with contractors.

Read the report here

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Projects

Slab-on-Grade Foundation Best Practices An evaluation of best practices for insulating under slab-on-grade foundations
Vacuum Insulated Panel Test CCHRC is testing how Vacuum Insulated Panels can be assembled to achieve extremely high R-values in cold climate homes.
Designs for Rural Alaska Walls Monitoring CCHRC demonstration homes for efficiency and moisture infiltration several years after construction.
Structural Insulated Panels Structural Insulated Panels (SIPs) are prefabricated building materials used in residential construction in Alaska. This project prepared resources for homeowners who want to learn about SIPs, where they are used in cold climates, and considerations for Alaska.
Energy Recovery Ventilators (ERVs) in Cold Climates Energy Recovery Ventilators (ERVs) are whole house ventilation systems that exchange stale indoor air with fresh outside air, recovering both heat and moisture from the indoor air to save energy. They have the potential to improve indoor air quality in a cold dry climate like Interior Alaska.