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.
Two moisture-storage coating mixtures developed and tested between late 1990 and early 1991 could provide a low-cost, building-integrated method of managing indoor humidity in hot and humid climates.
A comprehensive literature review was made to investigate whole house ventilation system options, various simulation and engineering analysis tools and techniques, and baselines for comparing the current project results.
This paper discusses the differences between vented, unvented and conditioned crawlspaces. Best practice construction techniques and assemblies for conditioned crawlspaces are discussed, the results of a field monitoring program are presented, and the code language addressing crawlspaces is explained.
This report summarizes indoor temperature and humidity data that have been collected from houses by the Building Science Consortium of the US Department of Energy Building America Program.
Americans have been building homes with wood—shaping logs, joining timbers, nailing studs—for almost 400 years. Our current approach, stick framing, grew poplular in the mid-1800's because it too less skill, required simpler tools, and took fewer people than timber framing. We apparently really like waste haulers, too.
With rising utility cost, concerns over availability of natural resources, and environmental impacts of our energy production and use, a push has been made to design buildings to minimize energy consumption in an attempt to work towards more sustainable communities. Creating more thermally efficient building enclosures is a necessary part of achieving this goal. The thermal resistance provided by insulating a stud cavity is limited by the standard framing sizes currently used in the United States and Canada. The options therefore are to either increase the depth of the studs used, add insulation to the interior of the wall assembly, or to add extra insulation to the exterior of the assembly. Providing rigid insulating sheathing to the exterior of a wall assembly is a technique that has been used in cold climates for more than 40 years. Recently it has begun to be integrated into enclosure designs in all climates. As with any newly adopted technology, there can be concerns for its proper application. This paper examines methods of incorporating insulating sheathing into the thermal and moisture management systems of the building enclosure in a variety of climate zones across North America. This is done through examining the material properties of the various products and how these properties can be used to achieve an energy efficient and durable building enclosure design, while avoiding problems relating moisture accumulation and degradation of materials.
This paper examines methods of using hygrothermal models, primarily WUFI, to assess the impact of energy efficient enclosure upgrades on the durability of historical buildings. Means of producing and choosing input data for the hygrothermal simulation are discussed. Methods for using the hourly results from the simulations to generate a corrosion index and a freeze-thaw count are developed. An example wall is used to demonstrate the type of output that can be expected and how this can be used in making retrofit design decisions.
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.
This is a test form used in the Building America program to ascertain house performance and specifications.
SNAPSHOT stands for Short, Non-destructive Approach to Provide Significant House Operation Thresholds.
Exposure to sunlight (ultraviolet radiation) and moisture are the major factors affecting the durability of paint coatings and the durability of the substrate.
Good design and practice involve controlling the wetting of building assemblies from both the exterior and interior and different climates require different approaches.
This is one of eleven projects from the full report of Building Science Consortium’s research efforts for 2004. The research program is aimed towards advanced building systems that have the potential to reduce residential building energy use by 50-60%. It is based on evaluation of market trends, industry partner needs, and initial results from our team’s system engineering research program. A total of eleven individual research projects were detailed in this report. This project report explores the development of more cost-effective, integrated supplemental dehumidification
systems.
Construction practices have improved and the HVAC systems need to improve with them. The deKieffer Bypass relieves air pressure in rooms without compromising sound or light transmission.
This article was written to tie together and summarize the various papers on unvented conditioned cathedralized attics found on our website.
An examination of five different systems that show how to cool and dehumidify inside air while maintaining sufficient introduction of outside air for ventilation efficiently and cost-effectively.
Heat loss from basements accounts for a significant portion of the energy loss from a home. In many jurisdictions, basement insulation is a building code requirement. Cost usually determines the type of insulation system used.
Twenty homes were tested and monitored in the hot-humid climate of Houston, Texas, U.S.A., to evaluate the humidity control performance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Fourteen houses, that also met measured energy efficiency criteria, had one of the six directly- or indirectly-integrated dehumidification and ventilation systems. Three reference houses had the same energy efficiency measures and controlled mechanical ventilation, while three other reference houses met code minimums for energy efficiency and did not have mechanical ventilation. Temperature and relative humidity were monitored at four living-space locations and in the conditioned attic where the space-conditioning equipment and air-distribution ducts were located. Equipment operational time was monitored for heating, cooling, dehumidification, and ventilation. Results showed that energy efficiency measures, combined with controlled mechanical ventilation, change the sensible and latent cooling load fractions such that supplemental dehumidification, in addition to that provided by the central cooling system, is required to maintain indoor relative humidity below 60% throughout the year. The system providing the best overall value, including humidity control, first cost, and operating cost, involved a standard dehumidifier located in a hall closet with a louvered door and central-fan-integrated supply ventilation with fan cycling.
This is a report describing the test methodology and results for experiments run on two test houses at the Bonita Springs development in Fort Myers, FL. The goal was to determine the effect of attic ventilation in a hot-humid climate; previous work had shown that little to no benefit is derived from ventilation in terms of energy use, and that it is detrimental for moisture control. Two houses with identical orientations and plans were compared; one was ventilated at the typical 1:300 ratio, and the other had sealed vents. This work was conducted in order to move houses in hot-humid climates forward in technology in their building envelope and HVAC systems.
Building America is a program of the U.S. Department of Energy, in which teams of architects, engineers, builders, equipment manufacturers, and others collaborate in a systems engineering approach to produce homes that use up to 50 percent less energy to operate.
