bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Round Robin on Apparent Thermal Conductivity of Several Loose-Fill Insulations
Authors: Adams RD , Hust JG 
Published: March 2009

The primary means of establishing the thermal performance of loose-fill insulation is ASTM Standard Practice C 687. To provide information for the development of a statement of precision and bias for this Standard Practice, a round robin was carried out by eleven laboratories measuring apparent thermal conductivity of four common loose-fill insulation products (cellulose, rock/slag wool, and bonded and unbonded glass fiber) and a glass fiber blanket.
The test results on the glass fiber blanket indicate that the measurement capability of the participants can be characterized by an imprecision of 3.0%, as measured by two standard deviations, and a negligible bias of the mean. The measurements on the loose-fill materials are characterized by an imprecision ranging from 21% for cellulose to 10% for the rock/slag wool. The increase in imprecision for the loose-fill materials is attributed primarily to inadequately defined procedures for preparing and conditioning the specimens.
A Theoretical and Experimental Study of Convective Effects in Loose-Fill Thermal Insulation
Authors: Langlais C , Arquis E , McCaa DJ 
Published: March 2009

Experimental results obtained by guarded hot box testing of low density loose-fill insulations have been analyzed using convective models. Closed and open specimens have been studied in an attic configuration with heat flow up. Experiments were conducted with and without a transverse air flow across the top of the specimens. The occurrence of convective movements inside the insulation was investigated for different applied thermal gradients and air permeabilities of insulation. Comparisons between theoretical and experimental results are presented and discussed.
The study has shown that the boundary conditions at the open top surface of an attic insulation are the driving force in determining thermal performance. Both the model and the experiments have shown that a significant reduction in thermal performance for presently used glass fiber insulations can only occur under severe climatic conditions (i.e., where a temperature difference greater than 40°C will be present).
Thermal Resistances of Metal Frame Wall Constructions Incorporating Various Combinations of Insulating Materials
Authors: Strzepek WR 
Published: March 2009

Series of thermal transmission tests were conducted on large wall specimens, which measured 300 by 400 cm (118 by 157 in.), using a calibrated hot box test apparatus. The wall specimens were constructed with metal framing members and were insulated with various combinations of materials.
Wall constructions were tested with and without batt insulation in the wall cavity in an attempt to determine the effect of the metal framing members on the thermal performance of the batts. In addition, the same wall specimens incorporated either wood fiberboard or extruded, expanded polystyrene (XEPS) foam sheathing to examine the effect of the metal framing members on the thermal performance of the sheathing.
The resistance values for the various wall constructions were measured at four different mean temperatures. The test results indicated that the metal framing members significantly reduced the effectiveness of the batt insulation and, to a lesser extent, the effectiveness of the sheathing. However, the batt insulation installed was slightly undersized in the width dimension and did not fill the entire wall cavity. As a result, the effect of the metal framing members on the thermal performance of the batts could not be accurately determined. R-values were calculated for the metal frame wall constructions using several analytical procedures. Some of the calculated values were in reasonably good agreement with the measured values.
Methods for Determining the Thermal Performance of Reflective Insulation Systems
Authors: Miller RG , Oscar DS , Seifaee F , Goss WP 
Published: March 2009

There has been no general agreement on how to perform, analyze, and report hot box tests on the thermal performance of reflective insulation systems which consist of a series of airspaces separated by reflective foils. This paper presents the results of experimental and analytical studies on the horizontal heat transfer through single- and multi-layer reflective insulations installed vertically. The multi-layer insulations were commercially available reflective insulation products. The experimental studies were carried out in a guarded hot plate and a calibrated hot box. The results showed the effect of aspect (height to width) ratio on the convective heat transfer in the air space. The experimental results were compared with a detailed three-dimensional finite element model of the conductive, convective, and radiative heat transfer which occurs in the reflective insulation system. The results were also compared with the original references used to determine the thermal resistance of plane reflective air spaces that are presented in the ASHRAE Fundamentals Handbook. These two analytical methods were also used to compare a wood and extruded polystyrene support structure for the reflective insulation product.
The results showed that the guarded hot plate did not adequately model the convective heat transfer, due to the low aspect ratio, and that a full-scale facility is needed to properly test a reflective insulation product. It was also indicated that the thermal performance of reflective insulation products are not comparable with the results for plane reflective airspaces in the ASHRAE Fundamentals Handbook due to the thermal bridges which characterize most reflective insulation products.
Influence of Natural Convection in an Insulated Cavity on the Thermal Performance of a Wall
Authors: Lecompte JGN 
Published: March 2009

The influence of the airtightness of the insulation layer in a partially filled cavity construction is discussed. In theory it is assumed that the insulation forms a continuous layer that is perfectly fixed against the inner wall of the cavity, leaving an air space between the outer wall and the insulation. However, in practice we frequently notice the presence of air gaps in the insulation layer, and of a second small cavity between the insulation and the inner wall. The influence of these inaccuracies on the heat transfer is studied by means of experimental research and computer simulations.
This paper presents the results of extensive measurements on a partially filled cavity wall (temperature profiles, heat loss), using a calibrated Hot Box-Cold Box. These results are compared with calculations of the temperature profiles and the overall heat transfer. A second series of measurements deals with the influence of the slope of the cavity.
Use of Two Heat Flow Transducers for Transient Thermal Measurements on Porous Insulating Materials
Authors: Langlais C , Boulant J 
Published: March 2009

A method for measuring the apparent thermal conductivity of fibrous insulating materials under non-steady-state conditions is presented. The apparatus comprises one specimen and two heat flow transducers.
Equations describing the variation of heat flow as a function of time and position are given. These equations are used to derive thermal transient properties from the heat flux measured on the cold and hot sides of the specimens.
Finally, measurements on a variety of fibrous insulating materials are presented. These measurements show good agreement between the apparent thermal conductivities measured under transient and steady-state conditions. A significant reduction in test times compared to classic measurements with a single heat flow transducer apparatus was obtained.
Modeling of Thermal Resistance Test Configurations That Use Thin Heaters
Authors: Yarbrough DW , McElroy DL , Graves RS 
Published: March 2009

The usefulness of a large unguarded thin screen heater as an integral part of a thermal resistance measurement apparatus for insulations has been demonstrated. Thermal modeling of existing and proposed test configurations can be used to establish applicability. HEATINGS, a general purpose conduction program, has been used to obtain the temperature distributions encountered in linear and radial heat flow testers with thin heaters.
Thermal simulations of the existing screen tester have been used to determine the effects of specimen thickness and thermal resistance on measurement errors. Simulation results were obtained for test configurations in order to provide a basis for design improvement (i.e., the effect of increasing levels of edge insulations on the apparent thermal conductivities obtained with the tester).
The extent to which limited edge guarding extends the operating range of a flat tester has been examined using HEATING5. A gradient guard along the edge of the specimen in the tester reduces the measurement errors due to edge heat loss. The improvement predicted by HEATING5 in measurement accuracy of a thin heater apparatus due to edge guarding that approximately matches the mean temperature on the edges with the mean temperature in the metering section has been examined experimentally.
Minimum Life-Cycle Cost Analysis of Residential Buildings for PC-Based Energy Conservation Standards
Authors: Tuluca A , Heidell J 
Published: March 2009

The proposed “Energy Conservation Standards for New Federal Residential Buildings” are embodied in an interactive computer program which analyzes over 400 Energy Conservation Options (ECOs) for 9 housing types and 5 fuels across 1000 U.S. climate zones. The program uses Life-Cycle Cost (LCC) economic analyses in a two-step procedure to derive a result close to the “economic optimum”: (1) an initial Savings-to-Investment Ratio (SIR) ranking, followed by (2) a series of Net Benefit (NB) iterations. Consideration is given to the interaction between the set of envelope and the set of mechanical equipment ECOs.
The distinctive.feature of the LCC algorithm is that it simultaneously evaluates these two sets of ECO types, and in doing so it keeps active the entire list of energy conservation measures through-out the NB calculations. Envelope ECOs found to be ineffective at a certain combination of heating/cooling mechanical equipment efficiencies are re-examined every time equipment efficiencies change. In a new context of efficiencies, these envelope ECOs may become cost-effective. Similarly, envelope ECOs which were before cost-effective may lose this status. The same process applies to the LCC evaluation of equipment ECOs within a changing loads context.
Implementing Thermal Insulation Product Standards
Authors: Nelson BD 
Published: March 2009

Product standards for residential thermal insulation were authorized by the Minnesota Legislature in response to the marketing of substandard insulation. In 1985 administrative rules established minimum standards for all residential insulation products sold or installed in the State. When possible, these requirements were based on industry consensus standards. The rules require manufacturers to file annual reports with the State, indicating that their products have been tested and meet the minimum standards. Manufacturers must also provide installation instructions to purchasers. Special testing provisions and installation instructions are required for insulations intended for use exterior below ground.
Manufacturers of insulation marketed in the State have been notified of this regulation. Filings of products are acknowledged by the State as being complete, or incomplete, with explanations as necessary. The State has published lists including products of 36 companies with completed filings and of those with filings in preparation.
Four areas have been particularly difficult in the design and implementation of this program. The first is deciding on equitable quality assurance requirements for manufacturers of insulation. A second is determining what products are acceptable for exterior foundation wall applications. Third is how consumers can identify which insulation products meet the standards. Finally, and probably most important, is how the installation of material can be improved so as to realize its full potential energy saving benefits.
The insulation manufacturing industry has been-very supportive of this program. In the first two years of its existence, the program has benefited both consumers and industry.
The Most Needed Building Foundations Research Products
Authors: Christian JE 
Published: March 2009

This paper describes a research program targeted towards the significant potential for energy savings from improved residential building foundations design. A recent study at the University of Minnesota estimates that less than 5% of foundations in the present building stock are optimally insulated. In addition, this study indicates that the potential national savings from upgraded basements, crawl spaces, and slab-on-grade foundation systems in residential and small commercial buildings is about 0.5 quads/year (0.523 × 1018 J/year).
This research program is based upon a research needs assessment developed by the Building Foundations Research Review Panel. This panel was established by the U.S. Department of Energy (DOE) and Oak Ridge National Laboratory to assist in the formulation of DOE foundations research policy and the development of a technology transfer strategy to get this research to the marketplace. Half of the panel members are from private industry.
One of the first tasks the panel addressed was to formulate a prioritized list of building foundation research needs.
Building foundations research needs include: widescale dissemination of existing information on good practices for energy-efficient construction and retrofit, accurate characterization of the thermal properties of soils, validated foundation heat and mass transfer algorithms coupled into whole-building simulation models, an experimental data base from one or more well-characterized test sites, and design tools to effectively transfer the results of research into practice.
On the Thermal Insulation of Outdoor Electronic Cabinets
Authors: Guglielmini G , Milano G 
Published: March 2009

The thermal behavior of electronic cabinets for outdoor installation is analyzed. As the correct working condition of circuit boards requires a temperature-conditioned housing, the thermal design of the cabinet structure must be carefully foreseen from both the insulating and cooling point of view.
After a short review of some technical solutions for passively conditioned cabinets, an approximate physical model is presented that is able to simulate with a sufficient degree of generality the transient thermal behavior of the structure as a whole. Several examples of numerical solutions are reported relating to different kinds of cabinets with or without natural air ventilation. The effect of thermal storage inside the cabinet is analyzed, too.
The numerical simulations show that for this kind of application any thermal calculation procedure must take into account the transient effect in all structural components.
Equipment and Methods for Assessing Surface Characteristics of a Road Network
Authors: Jordan PG 
Published: March 2009

A high-speed road monitor (HRM) has been developed for measuring road surface characteristics and road alignment. It simultaneously measures longitudinal profile, rutting, macrotexture, and road alignment while traveling in the normal traffic stream. Correlation coefficients exceeding 0.9 have been obtained between manual surveys of profile, rut, texture, and road alignment, and the corresponding HRM measurements. The relationship between surface data and road condition has been investigated, and change profile unevenness with time has been found to be a useful indicator of road deterioration. Other investigations particularly into ride have provided criteria for assessing the serviceability level of a road.
For routine use, a computer-analysis program has been developed to analyze the large volumes of data collected by the HRM. The paper describes the main elements of the program and concludes that the combination of equipment and analysis system provides a cost-effective surveying and assessment system for a primary road network.
Analysis of Transverse Unevenness with Respect to Traffic Safety
Authors: Kamplade J 
Published: March 2009

SAQ, a device to measure and evaluate transverse unevenness due to ruts in asphalt roadways, is described. This is a mobile system used to record horizon referenced transverse profiles in a drive/stop process. It includes a microcomputer for processing all relevant parameters on board the measurement vehicle. Methods of the automated profile analysis are discussed, and different characteristic values for the evaluation of transverse unevenness are proposed.
Tracking and hydroplaning effects are caused by ruts which may affect traffic safety. In wet weather, skid resistance and the effects of transition zones (areas where the transverse slope changes) also have an influence on the accident figures in conjunction with the rutting problem. These parameters were investigated on a large number of autobahn segments. The results show that on roadways with mean and good skid resistance, accident rates under wet conditions tend to decrease as the rut or water depth increases. Only in transition zones, which feature unexpected obstructions to water run-off for the driver, is there an increase in the accident rate under wet conditions with increasing hypothetical water depth in the ruts. In addition, the accident risk in transition zones under wet conditions is also generally higher. The skid resistance always has a dominant effect on the accident rate under wet conditions. For road-maintenance measures, skid resistance therefore must be accorded clear priority over transverse unevenness.
Theoretical Principles, Methods, and Equipment for Pavement-Condition Measurements Specific for Road Management Systems
Authors: Procházka M , Kropáč O , Šprinc J , Lehovec F 
Published: March 2009

Present developments in the field of pavement-management systems are primarily concerned with seeking relations between users' costs and variable pavement parameters. In this respect, the description and assessment of pavement-surface characteristics with regard to vehicle-pavement interaction and its stochastic character are of extreme importance. Only such an approach makes it possible to obtain both justified criteria and sought limit values for the models describing their development during pavement performance under traffic loads and the effect of climatic factors.
The marked stochastic character is inherent not only in surface characteristics as such, but also in the response of the vehicle and measurement equipment during their travels along the pavement. Therefore, theoretical foundations are presented along with assessment methods, response-type measuring devices, and routine methods used in the measurements of surface characteristics of highway and airfield pavements based on the theory of random functions, which have been introduced in Czechoslovakia.
The ascertained relations of pavement-surface characteristics are expressed most frequently by means of power spectral densities. Numerous results of in-site measurements, particularly by the mass-scale data collection in the highway network, may be processed in such a way that simple analytical functions or numerical constants may be deduced. However, the solution is always based on random-process theory and respects the vehicle-pavement interaction.
This simplified approach also forms the basis of the classification of vehicle response by means of the variance of vertical acceleration and, in a derived manner, also the classification of pavement unevenness by means of a logically introduced unevenness index.
The selected probabilistic approach based on vehicle dynamics also causes certain difficulties and limitations, for example, in the identification of the pavement-surface megatexture band (wavelengths from 0.5 up to 100 m) or in the solution of the influence of the respective unevenness band on skid resistance, which concerns tire-pavement interaction.
In spite of these problems, the stochastic concept of the solution of the problems of pavement-surface characteristics can be considered an efficient instrument which can considerably accelerate the finding of the sought relations between the technical and economic parameters in the design of the structure and quantification of the couples in full management systems.
Splash and Spray
Authors: Pilkington GB 
Published: March 2009

Like low pavement skid resistance, the aerodynamic phenomena of splash and spray are evident only when the pavement is wet. However, unlike low pavement skid resistance, splash and spray are separable and uniquely identifiable: (1) Splash is the mechanical action of a vehicle's tire forcing water out of its path. Splash is generally defined as water drops greater than 1.0 mm (0.04 in.) in diameter which follow a ballistic path away from the tire. (2) Spray is formed when water droplets, generally less than 0.5 mm (0.02 in.) in diameter and suspended in the air, are formed after water has impacted a smooth surface and been atomized. Several factors must be present: (a) water in the tire path (the thicker the water film, the greater the quantity of splash and spray generated); (b) pavement surface characteristics (thicker water films are retained on a nonporous surface); and (c) turbulent and high-velocity air masses generated by the combination of vehicle configuration and speed.
The Federal Highway Administration (FHWA) splash and spray research included driver simulator and wind-tunnel experiments, full-scale component, vehicle configuration, and countermeasure evaluations on test tracks, and cost-effectiveness analyses. The main findings were sixfold: 1. The driver simulator—A driver would not lose control of the vehicle due to the temporary visual obscurity due to the spray cloud, the turbulent air mass suspending the water droplets. 2. The wind tunnel—The areas were found where the spray cloud would be the densest, that is, the vehicle bow wave, around the wheels, and at gaps. 3. The full-scale component evaluations—Splash is water thrown away from the tire to the front (tire bow wave), to the side (side wave), and to the rear (tread pickup). Spray is water that the tire has picked up due to capillary adhesion and is stripped from the tire as it rotates and is atomized as it impacts the vehicle undercarriage. The splash from the tire that impacts the vehicle undercarriage will also be atomized and contribute to the spray cloud; however, only tread pickup is a major contributor to the cloud. 4. The full-scale configuration evaluations—these confirmed the wind tunnel findings. 5. The full-scale countermeasure evaluations—Spray can be effectively reduced by on-board countermeasures, such as baffles, dams, and drag shields, which reduce the size of the turbulent air mass. 6. The cost—effectiveness analyses-The most appropriate on-board countermeasures are cost effective on both regional and annual bases.
However, like improvement of skid resistance, the most effective and global countermeasures to reduce splash and spray are those applied at the pavement surface to reduce the amount of water in the tire path.