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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Performance of a Hot-Dry Climate Whole-House Retrofit

The Stockton house retrofit is a two-story Tudor style single family deep retrofit in the hot-dry climate of Stockton, CA. The home is representative of a deep retrofit option of the scaled home energy upgrade packages offered to targeted neighborhoods under the pilot Large-Scale Retrofit Program (LSRP) administered by the Alliance for Residential Building Innovation (ARBI). Deep retrofit packages expand on the standard package by adding HVAC, water heater and window upgrades to the ducting, attic and floor insulation, domestic hot water insulation, envelope sealing, lighting and ventilation upgrades. Site energy savings with the deep retrofit were 23% compared to the pre-retrofit case, and 15% higher than the savings estimated for the standard retrofit package. Energy savings were largely a result of the water heater upgrade, and a combination of the envelope sealing, insulation and HVAC upgrade. The HVAC system was of higher efficiency than the building code standard. Overall the financed retrofit would have been more cost effective had a less expensive HVAC system been selected and barriers to wall insulation remedied. The homeowner experienced improved comfort throughout the monitored period and was satisfied with the resulting utility bill savings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Technology Solutions Case Study: Hygrothermal Performance of a Double-Stud Cellulose Wall

Moisture problems within the building shell can be caused by a number of factors including excess interior moisture that is transported into the wall through air leakage and vapor drive, bulk water intrusion from leaks and wind-driven rain, capillary action from concrete to wood connections, and through wetted building materials such as siding wetted from rain splash back. With the increasing thickness of walls, moisture issues could increase. Several builders have successfully used “double-wall” systems to more practically achieve higher R-values in thicker framed walls. A double wall typically consists of a load-bearing external frame wall constructed with 2 × 4 framing at 16 in. on center using conventional methods. After the building is enclosed, an additional frame wall is constructed several inches inside the load-bearing wall. Several researchers have used moisture modeling software to conduct extensive analysis of these assemblies; however, little field research has been conducted to validate the results. In this project, the Building America research team Consortium for Advanced Residential Buildings monitored a double-stud assembly in climate zone 5A to determine the accu¬racy of moisture modeling and make recommendations to ensure durable and efficient assemblies.

Building America↗
DOE OSTI2021

Cost Analysis of Annual and Monthly Net Zero Energy Performance for Multifamily Buildings in the United States

As the United States continues its progress toward sustainable construction, net zero building design is becoming an increasingly important and popular topic. Two definitions of net zero energy performance, monthly and annual, provide different levels of energy autonomy and efficiency within a building. This article analyzes the viability and incremental cost for two-, three-, and four-story multifamily apartment buildings to reach both annual and monthly net zero energy performance throughout four climate zones in the United States using baseline reference buildings that represent current construction practices. Building size plays a large role in determining the capability for a building model to reach annual or monthly net zero. Two-story buildings are capable of reaching annual net zero with an increase in construction cost of about 4.4–5.6%. Three-story buildings in warmer climates can achieve annual net zero with an increase of about 5.1%, but models in colder climates cannot reach annual net zero performance. Four-story buildings cannot achieve net zero, owing to insufficient building area for solar arrays to produce electricity. Monthly net zero energy performance was significantly harder to achieve, with the only case reaching this goal being the two-story Houston based model, at an added cost of 8.2%. Generally speaking, only small buildings in warm climates will be able to achieve monthly net zero without vastly oversizing photovoltaic systems and increasing costs without adequate payback.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Practical challenges of model predictive control (MPC) for grid interactive small and medium commercial buildings

To the urgent call for mitigating climate change, substantial initiatives have been undertaken to deploy grid-interactive heating, ventilation, and air-conditioning (HVAC) controls, such as model predictive control (MPC) for buildings. These efforts typically aim to curtail peak energy demand, shift load and enhance overall energy efficiency. With the recent development of low-cost MPC technologies that don’t require extensive instrumentation or manual modeling, small and medium commercial buildings (SMCBs), which rarely utilize advanced HVAC control systems, have become candidates for grid-interactive efficient buildings (GEBs). However, despite the potential benefits and maturity of the technology itself, several practical challenges remain in real-world implementation. In this paper, we share the practical challenges that we have encountered in implementing and testing three types of MPC solutions (ON/OFF unit, dualfuel, and VRF systems) on multiple SMCB sites. We describe the MPC deployment process and discuss the lessons learned. The site selection, eligibility, and retrofit availability (e.g., utility price structure, thermostat communications, etc.) are the main discussion points at the beginning of the project. Also, the modeling automation and the best practices for interacting with endusers and handling erroneous situations are presented for successful operations.

woo Ham, Sang↗
NASA NTRS1992

JEFF: Air transport system design simulation

Jeff is a remotely piloted vehicle designed by the Blue Team, a division of AE441, Inc., to fulfill the mission proposed by G-Dome Enterprises: to build a cost efficient aircraft to service Aeroworld with overnight cargo delivery. The design of Jeff was most significantly influenced by the need to minimize costs. This objective was pursued by building fewer large planes as opposed to many small planes. Thus, by building an aircraft with a large payload capacity, G-Dome Enterprises will be able to minimize the large costs and the large number of cycles that are associated with a large fleet. Another factor which had a significant influence on our design was the constraint that our design had to fit into a 2'x2'x5' storage container. This constraint meant that unless we wanted to build foldable wings that Jeff's span would be limited to 10 feet. Since this was not enough lifting surface to suit our needs a canard configuration was chosen to get the needed lifting surface and avoid the structural dilemma of foldable wings. The aircraft is constructed mainly of balsa, with spruce wing and canard spars and a monokote covering. It was designed to support a maximum payload weight of 35 oz. (total aircraft weight of 108 oz.) and withstand a maximum load factor of 2.5.

Source record↗
DOE OSTI2024

Innovating the next generation of commercial smart building software

Nearly 30% of commercial building energy use is wasted due to equipment faults and HVAC controls problems. The result is increased emissions, compromised comfort and productivity, and less reliable coordination of building power needs with a clean grid. The energy impact alone represents $17 billion in potential savings. Today’s smart building software provides a robust solution to address these operational deficiencies. Energy management and information systems (EMIS) are saving up to 9% on average, with two-year paybacks. They are being incorporated into energy management processes, commissioning services, and utility programs. As effective as they are, two barriers prevent even deeper benefits; limited personnel to fix problems once they are identified, and the expense and time to manually implement changes in control systems. In partnership with the research community, the EMIS industry is developing new capabilities to overcome these barriers. Moving beyond siloed products for either fault detection and diagnostics, or optimal control, these new capabilities empower users to not only automatically identify faults, but also to push corrective action, and control improvements to their buildings. In this paper, several areas for enhancements are documented: ‘one-time’ correction of faults such as setpoints, schedules, and economizer lockouts; short-term active testing for automated proportional integral derivative (PID) loop tuning and functional testing; and continuous supervisory control for demand flexibility and year-round efficiency. Results are presented from a pair of partner implementations out of a dozen providers integrating these enhancements into their products, including field tests from across the country, and insights into operator acceptance and integration into operations and maintenance practices.

Casillas, Armando↗
DOE OSTI2014

Building Energy Codes Program: National Benefits Assessment (1992-2040)

Building energy codes and standards set minimum requirements for energy-efficient design and construction for new and renovated buildings, assuring reductions in energy use and greenhouse gas emissions over the life of buildings. DOE, through the Building Energy Codes Program, supports the improvement of energy efficiency in buildings. BECP periodically assesses the impacts of its activities by estimating historical and projected energy savings, consumer savings, and avoided emissions. The Pacific Northwest National Laboratory conducted the codes benefits assessment in support of the BECP. Underlying the assessment is a series of calculations that estimate and compare energy savings under two scenarios: "with BECP" and "without BECP." The analysis covers the years 1992-2040 and includes comparing the nominal energy savings (assuming 100 percent adoption and compliance) attributable to different code versions, determining the applicable floor space (both residential and commercial) subject to the code, and estimating the final energy savings by adjusting nominal energy savings for the applicable floor space according to the estimated actual adoption and compliance levels. The resulting estimates of energy consumption for each scenario are compared, and the difference equals the impact of BECP activities.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

National Cost-effectiveness of ANSI/ASHRAE/IES Standard 90.1-2013

The U.S. Department of Energy (DOE) Building Energy Codes Program supports the upgrade and implementation of building energy codes and standards, which set minimum requirements for energy-efficient design and construction for new and renovated buildings, and impact energy use and greenhouse gas emissions for the life of buildings. Continuous improvement of building energy efficiency is achieved by periodically updating model energy codes for commercial and residential buildings. Through consensus-based code development processes, DOE recommends revisions and amendments, supporting technologically feasible and economically justified energy efficiency measures. Ensuring that model code changes impacting the cost of building construction, maintenance, and energy services are cost-effective also encourages their adoption and implementation at the state and local levels. Pacific Northwest National Laboratory (PNNL) prepared this analysis to support DOE in evaluating the energy and economic impacts associated with updated codes in commercial buildings. The purpose of this analysis is to examine the cost-effectiveness of the 2013 edition of ANSI/ASHRAE/IES Standard 90.1 (ANSI/ASHRAE/IES 2013). Standard 90.1 is developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard Standing Project Committee (SSPC) 90.1. It is the model energy standard for commercial and multifamily residential buildings over three floors (42 USC 6833). PNNL analyzed the cost-effectiveness of changes in Standard 90.1 from 90.1-2010 to 90.1-2013, as applied in commercial buildings across the United States. During the development of new editions of Standard 90.1, the cost-effectiveness of individual changes (addenda) is often calculated to support the deliberations of ASHRAE Standard Standing Project Committee (SSPC) 90.1. The ASHRAE process, however, does not include analysis of the cost-effectiveness of the entire package of addenda from one edition of the standard to the next, which is of particular interest to adopting State and local governments. Providing States with an analysis of costeffectiveness may encourage more rapid adoption of newer editions of energy codes based on Standard 90.1. This information may also inform the development of future editions of Standard 90.1.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

pnnl/CPACE

C-PACE Market Assessment Tool This tool was developed for the U.S. Department of Energy’s Commercial Property Assessed Clean Energy (C-PACE) Working Group to support state and local governments creating, joining, and implementing C-PACE programs. This tool allows users to input a jurisdiction (city, county, or state) and automate a report with building characteristics, energy use, and energy efficiency savings opportunities for commercial buildings in that jurisdiction. The report generated by the tool identifies jurisdiction-specific energy end uses, building use types, and building technologies that a local C-PACE program should consider focusing on to more effectively allocate limited resources and maximize energy savings and investment.

Keene, Kevin↗
DOE OSTI2014

Energy Efficiency and Conservation Block Grant (EECBG)- Better Buildings Neighborhood Program Final Report

The original BetterBuildings for Greensboro grant program included an outreach campaign to inform 100% of the Greensboro community about the benefits of reducing energy use; a plan to reduce energy consumption in at least 34% of the homes and 10% of the other buildings in the east Greensboro target area; and a plan to create and retain jobs in the energy conservation industry. Under the original program structure the City of Greensboro planned to partner with local and regional lenders to create a diversified portfolio of loan products to meet the needs of various income levels and building types. All participants would participate in the loan programs as a method of meeting the program’s 5 to1 private capital match/leverage requirements. In June 2011 the program was restructured to include partnerships with large commercial and multifamily projects, with these partners providing the greater portion of the required match/leverage. The geographic focus was revised to include reducing energy consumption across the entire City of Greensboro, targeting neighborhoods with high concentrations of low-moderate income households and aged housing stock. The community outreach component used a neighborhood-based approach to train community residents and volunteers to conduct door-to-door neighborhood sweeps; delivered high quality information on available program resources; helped residents to evaluate alternative energy efficiency measures and alternative financing sources; assisted with contractor selections and monitoring/evaluation of work; coordinated activities with BetterBuildings program partners; and collected data required by the Department of Energy. Additionally, HERO (Home Energy Response Officers) delivered intro packages (energy efficiency information and products) to thousands of households at the initial point of contact. A pilot program (Early Adopters) was offered from March 1, 2011 through June 30, 2011. The Early Adopters program was designed to offer immediate assistance to property owners ready and able to make their homes more energy efficient, by offering a rebate on their energy assessment and on the cost of upgrades installed. Eligible energy efficient upgrades were inclusive of basic level insulating and weather-stripping, HVAC system and water heater upgrades, to whole home upgrades that include the replacement of windows, doors and appliances. Renewable energy systems such as solar hot water systems were also eligible for the rebate program.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Pathways for decarbonization of the buildings sector in Ukraine

The paper focuses on Ukraine’s intention to achieve a two-thirds reduction in buildings’ energy consumption for heating and cooling by 2050, concurrently aiming for net zero greenhouse gas emissions and heightened energy security. Here, the study examines the outcomes of retrofitting existing residential, commercial, and public buildings with highly efficient materials, improving construction standards, and transitioning to advanced heating systems. However, Russia’s invasion in 2022 inflicted substantial damage, prompting a shift from retrofit and decarbonization to reconstruction. The Ukrainian government’s Reconstruction Plan emphasizes clean, sustainable, and resilient energy systems. The study employs energy system and integrated assessment models (TIMES-Ukraine and GCAM-Ukraine) to explore scenarios taking into consideration the war, reconstruction, and a net zero CO 2 pathway. Using two models allowed the inter-model comparison. The analysis addresses vital questions on energy resiliency measures and the compounding effects of decarbonization. Findings indicate that Ukraine’s energy goals can be met through strategic retrofitting and economy-wide decarbonization, emphasizing the importance of low-carbon alternatives like district heating with renewable sources. Electrification with renewables and fuel-switching emerges as crucial for achieving building decarbonization. The study offers valuable insights into navigating energy challenges amidst the war and outlines a pathway for Ukraine’s sustainable energy future.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Dynamic Modeling, Trajectory Optimization, and Linear Control of Cable-Driven Parallel Robots for Automated Panelized Building Retrofits

The construction industry faces a growing need for automation to reduce costs, improve accuracy and productivity, and address labor shortages. One area that stands to benefit significantly from automation is panelized prefabricated building envelope retrofits, which can improve a building’s energy efficiency in heating and cooling interior spaces. In this paper, we propose using cable-driven parallel robots (CDPRs), which can effectively lift and handle large objects, to install these panels. However, implementing CDPRs presents significant challenges because of their nonlinear dynamics, complex trajectory planning, and precise control requirements. To tackle these challenges, this work focuses on a new application of established control and trajectory optimization theories in a CDPR simulation of a building envelope retrofit under real-world conditions. We first model the dynamics of CDPRs, highlighting the critical role of damping in system behavior. Building on this dynamic model, we formulate a trajectory optimization problem to generate feasible and efficient motion plans for the robot under operational and environmental constraints. Given the high precision required in the construction industry, accurately tracking the optimized trajectory is essential. However, challenges such as partial observability and external vibrations complicate this task. To address these issues, a Linear Quadratic Gaussian control framework is applied, enabling the robot to track the optimized trajectories with precision. Simulation results show that the proposed controller enables precise end effector positioning with errors under 4 mm, even in the presence of external wind disturbances. Through comprehensive simulations, our approach allows for an in-depth exploration of the system’s nonlinear dynamics, trajectory optimization, and control strategies under controlled yet highly realistic conditions. The results demonstrate the feasibility of CDPRs for automating panel installation and provide insights into their practical deployment.

CDPR↗
NASA NTRS1992

Industry survey of space system cost benefits from New Ways Of Doing Business

The cost of designing, building and operating space system hardware has always been expensive. Small quantities of specialty parts escalate engineering design, production and operations cost. Funding cutbacks and shrinking revenues dictate aggressive cost saving programs. NASA's highest priority is providing economical transportation to and from space. Over the past three decades NASA has seen technological advances that provide grater efficiencies in designing, building, and operating of space system hardware. As future programs such as NLS, LUTE and SEI begin, these greater efficiencies and cost savings should be reflected in the cost models. There are several New Ways Of Doing Business (NWODB) which, when fully implemented will reduce space system costs. These philosophies and/or culture changes are integrated in five areas: (1) More Extensive Pre-Phase C/D & E, (2) Multi Year Funding Stability, (3) Improved Quality, Management and Procurement Processes, (4) Advanced Design Methods, and (5) Advanced Production Methods. Following is an overview of NWODB and the Cost Quantification Analysis results using an industry survey, one of the four quantification techniques used in the study. The NWODB Cost Quantification Analysis is a study performed at Marshall Space Flight Center by the Engineering Cost Group, Applied Research Incorporated and Pittsburg State University. This study took place over a period of four months in mid 1992. The purpose of the study was to identify potential NWODB which could lead to improved cost effectiveness within NASA and to quantify potential cost benefits that might accrue if these NWODB were implemented.

Rosmait, Russell L.↗
DOE OSTI2015

Low-Cost, High Efficiency Integration of Solid-State Lighting and Building Controls Using a PET Power Distribution System (Final Report)

This final report describes the VoltServer Phase I effort to develop a method for distributing high voltage DC (HVDC) power in natively digital format for solid state lighting that is intrinsically safe, highly efficient, and capable of embedding data signals directly onto the power distribution channel. By building fault-detection capability into the power distribution backbone itself, the proposed technology addresses key limitations of existing DC distribution solutions, such as Power over Ethernet (PoE).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Colored ultrathin hybrid photovoltaics with high quantum efficiency

Most current solar panels are fabricated via complex processes using expensive semiconductor materials, and they are rigid and heavy with a dull, black appearance. As a result of their non-aesthetic appearance and weight, they are primarily installed on rooftops to minimize their negative impact on building appearance. The large surfaces and interiors of modern buildings are not efficiently utilized for potential electric power generation. Here, we introduce dual-function solar cells based on ultrathin dopant-free amorphous silicon embedded in an optical cavity that not only efficiently extract the photogenerated carriers but also display distinctive colors with the desired angle-insensitive appearances. Light-energy-harvesting colored signage is demonstrated. Furthermore, a cascaded photovoltaics scheme based on tunable spectrum splitting can be employed to increase power efficiency by absorbing a broader band of light energy. Furthermore, this study pioneers a new approach to architecturally compatible and decorative thin-film photovoltaics.

14 SOLAR ENERGY↗
DOE OSTI2012

Do We Really Know how Much it Costs to Construct High Performance Buildings?

Understanding the cost of energy efficient construction is critical to decision makers in building design, code development, and energy analysis. How much does it cost to upgrade from R-13 to R-19 in a building wall? How much do low-e windows really cost? Can we put a dollar figure on commissioning? Answers to these questions have a fuzzy nature, based on educated guesses and industry lore. The response depends on location, perspective, bulk buying, and hand waving. This paper explores the development of a web tool intended to serve as a publicly available repository of building component costs. In 2011 the U.S. Department of Energy (DOE) funded the launch of a web tool called the Building Component Cost Community (BC3), dedicated to publishing building component costs from documented sources, actively gathering verifiable cost data from the users, and collecting feedback from a wide range of participants on the quality of the posted cost data. The updated BC3 database, available at http://bc3.pnnl.gov, went live on April 30, 2012. BC3 serves as the ultimate source of the energy-related component costs for DOE’s residential code development activities, including cost-effectiveness analyses. The paper discusses BC3 objectives, structure, functionality and the current content of the database. It aims to facilitate a dialog about the lack of verifiable transparent cost data, as well as introduce a web tool that helps to address the problem. The questions posed above will also be addressed by this paper, but they have to be resolved by the user community by providing feedback and cost data to the BC3 database, thus increasing transparency and removing information asymmetry.

building component cost, code requirements, IECC, ↗
DOE OSTI2023

Machine Learning for Advanced Building Construction: Preprint

High-efficiency retrofits can play a key role in reducing carbon emissions associated with buildings if processes can be scaled-up to reduce cost, time, and disruption. Here we demonstrate an artificial intelligence/computer vision (AI/CV)- enabled framework for converting exterior build scans and dimensional data directly into manufacturing and installation specifications for overclad panels. In our workflow point clouds associated with LiDAR-scanned buildings are segmented into a facade feature space, vectorized features are extracted using an iterative random-sampling consensus algorithm, and from this representation an optimal panel design plan satisfying manufacturing constraints is generated. This system and the corresponding construction process is demonstrated on a test facade structure constructed at the National Renewable Energy Laboratory (NREL). We also include a brief summary of a techno-economic study designed to estimate the potential energy and cost impact of this new system.

building retrofits↗