Wall Upgrades for Deep Residential Energy Renovation

Lead Performer:  Pacific Northwest National Laboratory – Richland, WA
Partners:
-- Oak Ridge National Laboratory – Oak Ridge, TN
-- University of Minnesota – Minneapolis, MN
-- Earth Advantage
-- Efficiency Solutions
DOE Total Funding:  $1,814,000
FY19 DOE Funding:  $605,000
Project Term:  October 1, 2018 – September 30, 2021
Funding Type:  Lab Call

Project Objective

This project seeks to identify cost-effective ways to retrofit residential wall assemblies that result in durable, energy-efficient, and marketable strategies for deep energy retrofits. The most common current practice for wall upgrades generally falls into two categories: drill and fill and bare-stud rehab. Both approaches have significant limitations, making them expensive, disruptive, and potentially risky.

PNNL and its partners will investigate methods for adding insulation and new siding over existing exterior siding. Potential advantages to this insulation approach include saving the expense of old siding removal while still not disrupting interior spaces and providing a new home appearance. An insulation assembly that can be applied over existing siding can also reduce the amount of hazardous dust generated, isolate in place hazardous materials associated with existing siding, and allow for air-sealing of the existing wall.

The project team will investigate the performance of the most promising wall insulation assemblies selected based on a literature review, an expert meeting, input from a project advisory group, thermal and hydrothermal modeling of candidate wall upgrade approaches, and a techno-economic analysis of each option. PNNL will further investigate favorable wall insulation upgrade approaches through lab and/or field testing. New approaches or materials may be needed to improve available assemblies and practices. Experiments will likely include experimental control assemblies that represent non-insulated walls and walls insulated using the drill-and-fill approach.

PNNL and its partners will test up to 20 wall systems in the cold climate and will demonstrate two systems. The final reports will inform remodelers and home performance contractors. 

Project Impact

The thermal performance of these upgraded wall systems will significantly reduce annual heating and cooling loads, and may also contribute to the ability of the structure to resist extreme weather events, and better enable connected thermostats to meet utility calls for demand response for either daily or seasonal peaks. The resulting wall systems may actually improve disaster resistance in addition to delivering energy savings and grid benefits.

Contacts

DOE Technology Manager: Eric Werling
Lead Performer: Michael Baechler, Pacific Northwest National Laboratory