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WSU Energy Program
 

Hygrothermal Research Project

Principal Investigators
Carolyn Roos, Ph.D. - WSU Energy Program - (360) 956-2156
Bob Tichy - WSU Wood Materials and Engineering Lab - (253) 529-0900

3d long house

Washington State University Natural Exposure Test Facility (NET), established in 2003 to monitor heat moisture transport characteristics of building systems.

Project funding

U.S. Department of Energy Office of Energy Efficiency and Renewable Energy
Weyerhaeuser
APA - The Engineered Wood Association
CertainTeed Corp.
Fortifiber Corp.

Reports

Washington State University Final Report
Oak Ridge National Laboratory Final Report

Oak Ridge National Laboratory

The Problem

Damage caused by uncontrolled moisture accumulation in building enclosures greatly concerns the construction and energy conservation communities. Since the introduction of new energy and ventilation standards beginning in the 1980s, there is a great deal of speculation about the effects these standards have on the hygrothermal performance of buildings. In addition, building products and assembly methods are constantly changing, all without a full understanding of how one product's thermal or moisture performance affects another. A comprehensive method for scientifically selecting building materials and designing assemblies that have superior energy and moisture performance is not implemented. This comes at a great cost to the construction industry and building owners.

The Project

This project is developing and implementing a unique systems engineering approach to design wood frame building assemblies that are energy efficient and moisture tolerant in the climate of the Pacific Northwest. The overall impact of successful project completion will be a thorough understanding of building component relationships within a wall system and how they influence hygrothermal performance. With this understanding, building professionals and component manufacturers will be able to scientifically design buildings and products that are directly responsive to natural and conditioned environments. This will provide builders with a higher degree of confidence in the durability of their structures. This will also allow the advocates for energy efficiency to maintain and advance the market for highly energy-efficient buildings.

As well as developing a system engineering approach to wall moisture evaluation, this project will test the viability of new materials and assembly methods developed by industry partners. Industry proposed testing proprietary solutions that are designed to limit the entry of exterior moisture and to accommodate needed drying cycles. The test assemblies represent new technologies that are appropriate and cost effective in the current building production environment. These proprietary solutions should provide the durability assurances needed to move the market toward improved energy efficient construction methods.

This project is unique because it proposes to apply a number of evaluation methods to a specific end result. Laboratory testing of building material hygrothermal properties, field-testing of full-scale wall samples, and evaluation using advanced computer modeling will all lead to the development of durable wall assemblies for a specific climate. This project is specifically targeted at developing results for wood framed construction in the challenging climate of the Pacific Northwest. The results of the project will include:

  • an expanded hygrothermal material property data base,
  • a fully instrumented natural exposure test facility,
  • uniform test methods including mold growth assessment tools,
  • an implemented systems engineering approach using the most advanced modeling tools, and
  • specific construction solutions for the Pacific Northwest climate.

Following conclusion of the project the model, some material property data and the results of all nonproprietary analyses will be disseminated with the assistance of the Engineered Wood Association (APA) and the project research team.

The Natural Exposure Test Facility

The Natural Exposure Test facility (NET) was constructed in 2003.

The 12 wall systems currently being studied were selected to demonstrate a variety of building methods anticipated to provide improved performance. This includes the study a variety of insulation systems, vapor control materials, cladding ventilation, and sheathing materials.

A sophisticated data acquisition system has been installed to provide hourly data on the performance of the test walls. For each wall cross section, numerous sensors directly measure the moisture content of building materials, vapor pressure, temperature, humidity and condensation.

The facility is located at the Washington State University Puyallup Research and Extension Center. For a map and driving directions go to: http://www.puyallup.wsu.edu/map.htm

Our Collaboration with Oakridge National Laboratory

This project is being conducted in conjunction with the Oakridge National Laboratory: Building Envelope Program, Dr. Achilles Karagiozis.

Report available:
Importance of Moisture Control in Building Performance
Achilles N. Karagiozis
Oak Ridge National Laboratory