Hygrothermal performance of materials for built environmental systems

HT_4B: high Environmental performance (HEP) –

residential Housing for NY state

Project led by Syracuse University and co-sponsored by Energy Resource Center / University of Illinois at Chicago under contract with The National Center for Energy Management and Building Technologies and supported by CoE – EQS is currently in the negotiation stage.

This project seeks to dramatically reduce the energy use of new homes built in New York State while providing a more comfortable and healthy indoor environment in addition to improving the durability of the construction. The project comprises of two stages involving three NYS-based partners: Northeast Natural Homes, a builder and consultant with experience in green building technologies; CDH Energy, a consulting firm with experience in energy and HVAC performance evaluation; and Syracuse University that has experience in construction materials, mechanical systems and indoor environment quality issues. Building Science Corporation, a leading member of the US Department of Energy’s Building America (BA) research program, will help ensure that methods to quantify field performance and presentation of results are consistent with past and ongoing efforts in residential energy efficiency. A significant federal co-funding from the University of Illinois at Chicago (UIC) through the National Center for Energy Management and Building Technologies (UIC/NCEMBT) is to develop and demonstrate high performance/zero energy technologies for residential buildings in cold climates – an area that has not been the focus of current national efforts in residential energy efficiency. 

Stage 1 is focused on laboratory evaluation and development of housing technologies suitable for the NYS homes. We envision evaluating several technologies that in combination will provide the means to meet or exceed the 40% energy saving compared to a BA reference house. We will also incorporate and evaluate technologies needed for an improved quality of indoor environment. Those technologies and approaches, which provide the best cost-benefit ratio will be implemented in a demonstration house. The second stage 2 of the project is focused on measuring and documenting field performance of the house and ultimately transferring that knowledge to the residential construction in NYS.

The fundamental premise of the design is a continuous, airtight building envelope, which also includes basement and attic spaces. The cathedral ceiling is un-vented and completely filled with a medium-density polyurethane spray foam insulation acting as a thermal insulation, air barrier and moisture control element. The continuity of thermal, air and moisture protection between roof, above and below grade walls is checked during the design and construction stages. This is a critical element of the system performance necessary for a number of reasons:

• to avoid condensation and potential mold that may be originated in unfinished and partly insulated basements i.e., to avoid basement spaces with poor indoor air quality that could contaminate the main living areas of the house
• to eliminate wetness in the attics and risk of material decay in the attics 
• to reduce the snow melting and eliminate and ice building at the edges of the roof
• to avoid drawing any ventilation ducting though unconditioned space (heat losses and unwanted air pressure modulation)
• to provide additional space with high quality environment for recreational activity in the basement
• to provide additional space with acceptable quality of environment for storage in the attics

The following environmental considerations are included in the project:

• all materials selected for the constructions will have low TVOC emissions
• An energy efficient ventilation system is installed at a demonstration site to provide the ventilation required in compliance with the ASHRAE Standard 62.2. The ventilation system will be commissioned to consider the natural leakage of the house so that the actual performance of the ventilation system is optimized to the requirements of indoor environment
• Controls that provide ventilation on demand will also be considered
• Heating will be provided by either a radiant or a hybrid system.

Two foundation systems will be considered (1) insulated concrete forms, or (2) prefabricated concrete panels.

Finally, there is a substantial component of the technology transfer built in this project. We intend to create an advisory group that would include representation of the following groups: Insurance industry, mortgage (banking) industry, building science and biological expertise (mold, insects), production builder, and panel prefabrication. Creation of such an advisory group at the formulation of the project will assist in defining interests of NY stakeholders for specific elements of technology transfer and provide means of increasing impact on the current market place.