Research Reports are technical reports written for researchers but accessible to design professionals and builders. These reports typically provide an in-depth study of a particular topic or describe the results of a research project. They are often peer reviewed and also provide support for advice given in our Building Science Digests. The most recent documents posted are at the top of the list below.
This report compares the moisture related performance of an exterior insulated wall to the performance of two other common construction methods, side-by-side. The data presented is a subset of experimental data from a multi-phase, multi-year research project at the Vancouver Field Exposure Test Facility led by Building Science Corporation (BSC) and Gauvin 2000 Construction Limited. The analysis includes results from normal operating conditions in a high stress exterior moisture environment (typical of the Pacific Northwest climate) and under intentional controlled wettings to the interior and exterior of the sheathing. There were no measured or observed moisture related durability concerns of the wood structural sheathing when 1.5” of exterior insulation was installed.
This report is an extension of a previous analysis study titled “High R Walls for the Pacific Northwest – A Hygrothermal Analysis of Various Exterior Wall Systems”, conducted by BSC for Walsh Construction, dated June 1, 2010 that examined the predicted thermal and hygrothermal performance of 17 different wall assemblies in Portland, Oregon.
This report summarizes hygrothermal analysis of specific attics constructed in California. The analysis was done using historical experience, published work in journals and trade publications, current building code requirements and WUFI hygrothermal simulations to assess benefits and risks associated with insulating the roof decks in both vented and unvented configurations. The majority of the configurations evaluated are well understood and have been addressed in previous published work or in the model building codes. However, the focus of this report is on modifying conventional, ventilated attics, constructed with impermeable roof shingles (with fiberglass batt insulation on the ceiling plane) by adding fiberglass batt (or netted fiberglass or netted cellulose or spray applied fiberglass) insulation to the underside of the roof deck (i.e. on the slope) while leaving the attic air space ventilated to outdoors.
This paper was first presented at the 2011 ASHRAE Annual Conference. A startup builder in the San Francisco Bay Area has a goal of producing factory built/modular houses with net zero energy performance. Their first prototype was a two-story, two bedroom, urban infill townhouse design. It has been in operation for roughly a year, and has been extensively measured and monitored, providing information about its net zero performance.
This report considers a number of promising wall systems that can meet the requirement for better thermal control. Unlike previous studies, this one considers performance in a more realistic matter, including some two- and three-dimensional heat flow and analysis of the relative risk of moisture damage.
The software CONTAM was used to create a calibrated mulit-zone model to replicate in-field tracer gas decay measurements of a new two story, 2,600 sq. ft., single-family house in Sacramento, CA under different whole-house dilution ventilation scenarios. This report was first published in ASHRAE Transactions (17, Louisville 2009). American Society of Heating Refrigeration and Air-Conditioning Engineers, Atlanta, GA. Reprinted with permission.
A calibrated ventilation model was exercised over a range of parameters seen in new and existing housing in the United States. This report was first published in ASHRAE Transactions (17, Louisville 2009). American Society of Heating Refrigeration and Air-Conditioning Engineers, Atlanta, GA. Reprinted with permission.
Exterior insulation and finishing systems (EIFS) are inherently defective and unfit of use as an exterior cladding system where moisture sensitive components are used without a provision for drainage or in locations and assemblies without adequate drying.
Concentrations of 54 volatile organic compounds (VOCs) and ventilation rates were measured in four new manufactured houses over 2-to-9.5 months following installation and in seven new site-built houses 1-to-2 months after completion. The houses were in four projects located in hot-humid and mixed-humid climates. They were finished and operational, but unoccupied.
Uniform distribution of outside air is one way to ensure that residential dilution ventilation systems will provide a known amount of fresh air to all rooms regardless of house geometry and occupant behavior.
In order for dilution ventilation systems to provide predictable results independent of the geometry of individual homes, outside air must be uniformly distributed throughout the house
A single-story, single-family, 1350 sq. ft. house located in Las Vegas, NV was outfitted with two separate ventilation systems. The systems were independent of each other, and were operated at different times to evaluate the relative difference in air change rate and distribution of ventilation air induced by their operation.
Traditionally, building codes have required that attics of residential buildings be vented. The ventilation requirement varies between one square foot of net free ventilation area per 300 square feet of attic floor area (1:300) to one square foot per 150 square feet (1:150).
Twelve affordable, healthy, environmentally responsible single family houses were designed and built on an urban infill in Dallas, Texas.
Sealed attic construction, by excluding vents to the exterior, can be a good way to exclude moisture-laden outside air from attic and may offer a more easily constructed alternative for air leakage control at the top of residential buildings.
Ventilation air change rate, local mean age-of-air, and interzonal ventilation air distribution were measured for two single-family homes and eight ventilation systems.
The overall goal of the DOE residential research program is to reduce average whole house energy use in new residential buildings by 30-90 percent by 2020, including homes that achieve zero net energy use on an annual basis. High performance space conditioning and control systems that match the high performance of Building America enclosures are necessary to meet performance targets. Conditioning systems with integrated mechanical ventilation and year-around temperature and humidity control are necessary. The most significant climate-specific need is for system-integrated dehumidification for humidity control without overcooling the space. Cost-effective dehumidification without overcooling will enable continued and further reduction of sensible loads (including high-performance glazing) that would otherwise exacerbate humidity control problems in humid climates.
Current work is focusing on the performance and durability of unvented-cathedralized attics in hot-humid climates with both tile and asphalt shingle roofing.
A residential attic model, contained in the finite element computer program FSEC 3.0, was empirically aligned with measured attic data from three roof research facilities in Florida and Illinois.
Side-by-side energy testing and monitoring was conducted on two houses in Louisville, KY.
