English

An insulated wall can be supported internally by thin steel studs. There will be extra heat loss caused by the metal U-studs, but slitting the web of the U-studs perpendicular to the heat flow direction reduces this heat loss. Calculation of the heat transmittance is a difficult numerical problem due to the high ratio of thermal conductivity between the insulation and the steel. This study presents result of calculations in three dimensions. The proper choice of the numerical mesh is discussed. Simplified equations for the U-factor are derived and implemented ill a computer program.

Whole-house tests were developed to compare the airflow resistance of several different materials used to seal the walls of a house at the outer surface. These airflow resistances were measured infield installations and include the effects of interactions with adjacent materials and assemblies. The materials tested were housewrap over fiberboard and foam sheathings, extruded polystyrene foam sheathing with the edges taped, extruded polystyrene sheathing with the edges untaped, and caulking and foaming the inside of the wall cavity.

A technique for improving the thermal performance of lightweight steel- and wood-framed building assemblies is introduced in this paper. In this approach, rigid extruded insulation material is applied only to the framing members themselves (studs, plates, doubles, headers, etc.), effectively creating a composite member composed of insulation and structural framing. The depth of the envelope cavity is thereby extended by an amount that is equal to the thickness of the rigid insulation employed.

A building's envelope is the product of the choice of framing materials and quality of craftsmanship. Exposed to weather, it may 1101 provide the same airtight conditions in which its insulation material had been tested. Air permeable insulation offers little resistance to pressure driven, or convective, heat loss. Air impermeable insulators can additionally reduce convective, as well as conductive, heat loss by being sprayed into and sealing up sources of infiltration normally addressed by caulks and sealants.

The effect of wall material configuration on dynamic thermal performance is analyzed for six typical wall configurations. Due to different arrangements of concrete and insulation layers, these walls present a wide range of dynamic thermal properties. Newly developed thermal structure factors are used in selection and thermal analysis of these walls. A simple one-room model of the building exposed to diurnal periodic temperature conditions is analyzed to give some basic information about the effect of wall material configuration on thermal stability of the building.

The purpose of this project was to devise a simple, experimentally validated method for quantifying the energy impacts of exterior envelope air leakage. Four full-size exterior envelope test specimens, two opaque wall systems and two fenestration systems, were built for determining simultaneous conductive and convective heat loss. The two opaque clear wall sections were metal-faced sandwich panel and cold formed steel frame.

In 1995, the U.S. Department of Energy (DOE) began planning for a new generation of building simulation tools. As part of this planning activity, DOE created an inventory of DOE-sponsored tools in early 1996. By mid-1996, this work had evolved into a web-based directory with information on 50 software tools. Today, the directory contains information on more than 125 tools from around the world. To inform the simulation tool planning efforts, DOE sponsored workshops in August 1995 and June 1996, inviting energy simulation developers and users.

This paper outlines the methods and results of a four-year project that measured heat flows through two uninsulated slab-on ground floors on nominally wet soils. One floor was on peat soil, the other on clay, and water table depths were 0.5 m to 1.0 m through most of the year. Heat fluxes were measured over the whole floor using heat flux transducers (HFT) at the concrete floor surface, and temperatures were measured by thermocouple, continuously for four years. The soil conductivities and soil temperatures were measured daily at 11 positions near one edge of the floors.