Inelastic chaotic scattering on a Bose-Einstein condensate

We devise a microscopic scattering approach to probe the excitation spectrum of a Bose-Einstein condensate. We show that the experimentally accessible scattering cross section exhibits universal Ericson fluctuations, with characteristic properties rooted in the underlying classical field equations.Comment: 11 pages, 5 figure

Evaporative-cooling potential for office buildings

This paper presents the results of both a performance and an economic assessment of the evaporative-cooling potential for office buildings in 11 US climate zones. Evaporative-cooling systems of the direct and combined direct/indirect type that are part of the heating, ventilating and air-conditioning (HVAC) system were evaluated. Thermal-storage strategies were not considered in this study. The DOE-2 building-energy-analysis computer program was used to simulate the evaporative-cooling performance of typical single-story and multistory office buildings. Performance results are presented as energy and peak demand reductions for each type of office building in each climate zone. Economic results are summarized as investment targets and aggregate/energy cost savings

ASHRAE's New Performance Measurement Protocols for Commercial Buildings

ASHRAE, CIBSE and USGBC are developing a standardized, consistent set of protocols to facilitate the comparison of the measured performance of buildings, especially those claimed to be green, sustainable, and/or high performance. Such protocols are needed because claims of high performance cannot be credible without such standardized protocols being applied consistently in the U.S. as well as internationally. The protocols will identify what is to be measured, how it is to be measured (instrumentation and spatial resolution), and how often it is to be measured. They will address both the use and reporting of the measured data, as well as appropriate benchmarks for each of the following characteristics: Energy Use (site, and source), Indoor Environmental Quality (IEQ)-Thermal Comfort, IEQ-Indoor Air Quality, IEQ-Lighting/ Daylighting Quality, IEQ-Acoustics and Water Use. The primary users of the protocols document will be building owners and facility managers, rating and labeling system developers, government officials, as well as architects and design engineers. To date, a scoping document has been developed, an extensive literature review has been performed (available on ASHRAE’s web site), and a committee formed to write the protocols, which are intended for publication in January 2009

Evaluating Texas State University Energy Consumption According to Productivity

The Energy Utilization Index, energy consumption per square foot of floor area, is the most commonly used index of building energy consumption. However, a building or facility exists solely to support the activities of its occupants. Floor area alone is not a complete measure of the amount of service a facility provides. The energy consumption of a service institution, such as a university, could be evaluated according to its annual level of service. However, the variety of services delivered by an institution of higher education cannot be measured by a single, readily available number. Data Envelopment Analysis, a tool used primarily in management science, can find "benchmark" input consumption levels for productive entities with multiple inputs and outputs. It finds a consumption target for each form of energy consumed by an institution, based on the actual performance of comparable institutions. This method is applicable to the energy consumption of Texas state institutions of higher education

Solar Energy Research Institute Validation Test House Site Handbook

The Validation Test House at the Solar Energy Research Institute in Golden, Colorado, is being used to collect performance data for analysis/design tool validation as part of the DOE Passive Solar Class A Performance Evaluation Program

Development of Revised Energy Standards for Texas Buildings: Preliminary Results

In 1977, the State of Texas published a two-part Energy Conservation Manual to aid designers, builders, and contractors in the design of energy-efficient state buildings. Under the sponsorship of the Governor's Energy Management Center, the Center for Energy Studies (CES) at The University of Texas at Austin is revising and updating the nonresidential building portion of the Energy Conservation Manual. The proposed revision is a Texas-specific adaptation of ASHRAE Standard 90.1P ("Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings"). These modifications include editorial changes, such as deletion of criteria that do not apply to Texas climates, as well as improved envelope criteria and the addition of HVAC system performance criteria. This paper documents the approach taken in the development of the revised Texas standards. Preliminary results are presented for the new envelope calculation procedures that will be included in the compliance software. This software will parallel that provided for the envelope and lighting sections in the ASHRAE Standard and will ultimately extend the standard to include a performance-based approach for HVAC systems and whole-building Energy Targets

Energy Analysis of the Texas Capitol Restoration

This paper presents the methodology and results of a detailed energy analysis of the Texas Capitol Restoration. The purpose of this analysis was two-fold: 1) to determine the projected energy cost savings of a series of design alternatives for the Capitol Restoration, and 2) to calibrate the simulation model of the Capitol in its prerestored condition (in September 1991) using monitored energy use data from the Texas LoanSTAR program. The Capitol in its proposed restored condition was simulated using the DOE-2 building energy analysis computer program with long-term Austin weather data to project the annual energy use, peak electric demand, and annual energy cost. Then a series of 13 energy efficient design altematives was simulated. The results were compared to those of the base case to determine the projected annual energy and energy cost savings for each measure, and for combinations of several of the measures. Finally, the paper documents the calibration of the DOE-2 model for the Capitol in its prerestored condition, using monitored hourly whole-building electric data (excluding heating and cooling energy)

Energy Savings Resulting from Shading Devices on Single-Family Residences in Austin, Texas

Potential annual energy savings resulting from window shading devices on three prototypical Austin, Texas, single-family residences were computed in this study. Savings were calculated for interior (shades, blinds, draperies, window film, and tinted windows) and exterior (solar screens, awnings, overhangs, and the effects of recessed windows and vegetation) shading devices. The analysis was conducted with the DOE-2 building energy analysis computer program. Nominal baseline cases (single glazing, gas heating, and nominal shading from eaves and neighboring buildings) were run for each prototype. Selected baseline variants (double glazing, all electric, and no eaves or neighbor shading) were run to test parameter sensitivity. Results are reported in terms of the annual heating and cooling energy use and energy cost, with each device in place, as compared to the baseline cases. The devices are ranked in term of energy savings and energy coat savings. Another significant result is the multiple-regression correlation of annual heating and cooling energy savings with Shading Coefficient and U-value that generalizes the performance of the shading devices

Development of HVAC System Performance Criteria Using Factorial Design and DOE-2 Simulation

A new approach is described for the development of Heating, Ventilating, and Air-conditioning (HVAC) System Performance Criteria for the Texas Building Energy Design Standard. This approach integrates a design of experimental methodology and DOE-2 simulation to identify the effects of control parameters on HVAC system energy performance. Three new criteria - transport, plant, and system performance factors-are used as measures of system performance. The procedure has been applied to the development of criteria for a variable-air-volume (VAV) and a constant-air-volume (CAV) system in three Texas climates. The results show that the air distribution system pressure loss, cooling coil exit temperature set-pint, operation of an economizer, and use of dead band controls have significant effects on air transport energy use and total system performance. The selection of control strategies and set-points have a clear impact on energy use. There is also a great energy-saving potential of converting from a CAV to a VAV system

An Expert System for Determining Compliance with the Texas Building Energy Design Standard

Demonstration of compliance with the Texas Building Energy Conservation Design Standard involves completion of a summary checklist for each of its sections. This manual checking is tedious. Furthermore, no comprehensive documentation of the user's compliance is provided and the compliance checker must manage the data collected. To assist designers in complying with the Standard and to reduce the time required, the Center for Energy Studies (CES) at the University of Texas at Austin has developed an expert system to serve as both the compliance procedure and its documentation. This expert system directs the user with queries (screen menus), prompting the user for all relevant information. A graphical user interface has been developed to facilitate quick navigation through the Standard, easy data entry, and identification of compliance failures. This paper describes the research approach to the expert system, the system features, current status of project, and the benefits to be derived from this innovative compliance tool