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At least 325 records · Page 18

All sources NASA NTRS DOE OSTI

DOE OSTI2022

Development and Validation of Algorithms That Analyze Communicating Thermostat Data to Identify Enclosure Retrofit Opportunities

This report, Development and Validation of Algorithms That Analyze Communicating Thermostat Data to Identify Enclosure Retrofit Opportunities , explores ways to automatically identify residential homes with enclosure retrofit opportunities; estimate prospective savings; and perform evaluation, measurement, and verification using interval data from communicating thermostats.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2024

The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost

This PowerPoint presentation summarizes the cost and performance results of the techno-economic analysis of membrane-based carbon capture retrofits at cement plants, published in June 2024, titled “The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost.” The analysis report used as a basis for slide contents was developed by NETL for publication in the scientific journal Carbon Capture Science and Technology.

Hughes, Sydney↗

DOE OSTI2024

The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost

Hughes, Sydney↗

DOE OSTI2026

Retrofit & Expansion Project at Ultra-High Molecular Weight Polyethylene Plant: Completing a Full Domestic Supply Chain for Lithium-Ion Batteries (Final Scientific and Technical Report)

The UTEC-1 LIBS Retrofit and Expansion Project aimed to retrofit and expand Braskem’s UHMWPE unit in La Porte, TX to produce lithium-ion battery separator (LIBS) grade material and increase capacity. The project sought to strengthen the domestic supply chain for advanced battery manufacturing and reduce reliance on imports. While significant progress was achieved in conceptual design and FEL-2 engineering, strategic realignment and external factors led to project termination prior to FEL-3 and FEED execution.

25 ENERGY STORAGE↗

DOE OSTI2024

Cable-Driven Parallel Robot (CDPR) for Panelized Envelope Retrofits: Feasible Workspace Analysis

Recent decades have seen remarkable progress in the field of robotic-assisted construction. Cable-driven parallel robots (CDPRs) emerge as promising tools for automating construction processes, due to their advantageous features such as scalability, reconfigurability, compact design, and high payload-to-weight ratio. This paper uses a simple static model to determine the feasibility of a CDPR for overclad panel installation in building envelope retrofits. Given that the building facade needs to be a subset of the CDPRs wrench-feasible workspace, we focus on the sensitivity of the workspace concerning various cable arrangements and CDPR frame sizes (e.g., height and width extensions). Our analysis indicates that no cable arrangement satisfies the requirement of complete facade coverage and avoids cable-to-panel collisions. Thus, frame extension is needed to enhance coverage. However, in densely populated areas where width extension is limited by space constraints, height extension alone is insufficient to guarantee full facade coverage. This paper pioneers the investigation of CDPRs for panelized envelope retrofits, showcasing their advantages and limitations and paving the way for further research and development.

Liu, Yifang↗

DOE OSTI2023

Regional Carbon Emission Reduction Prediction via Retrofits of Commercial Buildings with a Case Study of US School Buildings in Hot Climates

Retrofitting commercial buildings has great potential to reduce carbon emissions as demonstrated by previous studies in some specific cities, but their regional carbon emission reduction potential is still unknown. Thus, we develop a method to predict the long-term regional carbon emission reduction potential by retrofitting commercial buildings. School buildings in hot climate zones in the continental U.S. are selected as an example. The results show that the aggregated carbon emission reduction potential of school buildings in that region reduces from 3.33 to 2.01 megatons from 2024 to 2050 due to the increased penetration of renewable energy.

building energy simulation↗

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↗

DOE OSTI2022

Field Measurement of Central CO2 Heat Pump Water Heater for Multifamily Retrofit

Domestic hot water heating of multifamily buildings accounts for a substantial portion of the energy load of existing buildings. This load is made up of both the energy required to produce hot water and the energy needed to maintain the temperature of the heated water within a building’s distribution piping so that heat can be promptly delivered to building occupants as needed. Properly designed heat pump water heater (HPWH) systems have the ability to improve efficiency in both water heating and temperature control operations. Further, CO2 heat pump technology reflects a shift away from traditional refrigerants and toward refrigerants with low global warming potential (GWP). In this paper’s case study, a design consisting of multiple CO2 heat pump water heaters (commonly used in single-family homes) with a novel “swing tank” was proposed to meet the demand for domestic hot water heating and recirculation loop temperature maintenance. The proposed design was applied to the retrofit of a 60-unit, low-rise, multi-family building located in the Pacific Northwest of the United States. The purpose of this paper is to verify the performance of the system including the proposed “swing tank” in a centralized SHW system using CO2 HPWH. It also provides practical information and lessons learned from the retrofit project. Long-term monitoring data showed that the system had a coefficient of performance (COP) of three or greater and provided an average of 20 gallons of hot water per day per apartment. The results of this work indicate that residential-scale CO2 HPWH equipment and a “swing tank” design can efficiently provide domestic hot water heating and temperature maintenance for mid-sized multifamily buildings.

Banks, Adria↗

DOE OSTI2026

Exploring Building Retrofit Strategies Using AutoBEM Under Future Weather Scenarios

This study evaluates the long-term effectiveness of energy conservation measures (ECMs) on building energy consumption using AutoBEM, a scalable modeling framework driven by the high-resolution Model America dataset. We simulated 18,951 buildings in Flagstaff, Arizona under four climate scenarios using Future Typical Meteorological Year (fTMY) weather files for six time periods spanning from 1980 to 2099. Six ECMs were analyzed across electricity and gas usage, including HVAC fuel-switching, insulation upgrades, and infiltration control. While some measures, such as reducing space infiltration by percentage, showed minimal or even negative impact on total energy savings at the aggregate level, they proved highly effective for specific building types. Conversely, HVAC electrification offers high gas reduction but shifts demand to electricity, highlighting critical trade-offs under different climate trajectories. Building-type-specific analysis under SSP5-RCP8.5 (2080–2099) revealed significant variation in ECM performance, underscoring the need for targeted retrofit strategies. This study demonstrates the power of combining fTMY projections with large-scale simulations to inform data-driven retrofit planning.

Chowdhury, Shovan [ORNL]↗

DOE OSTI2013

Prologis Rolls Out Warehouse Energy Retrofits

Prologis partnered with the U.S. Department of Energy (DOE) to develop and implement solutions to retrofit existing buildings to reduce annual energy consumption by at least 30% versus pre-retrofit energy use as part of DOE’s Commercial Building Partnership (CBP) program.

cbp↗

DOE OSTI2015

Technology Solutions Case Study: Durable Interior Foundation Insulation Retrofits for Cold Climates, Cloquet, Minnesota

Thermal and moisture problems in existing basements create a unique challenge as the exterior face of the wall is not easily or inexpensively accessible. This approach by the NorthernSTAR Building America Partnership team addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. It is effective at reducing energy loss through the wall principally during the heating season. The team conducted experiments at the Cloquet Residential Research Facility to test the heat and moisture performance of four hollow masonry block wall systems and two rim-joist systems. These systems were retrofitted with interior insulation in compliance with the 2012 IECC. The research showed for the first time that, for masonry block walls in a cold climate, a solid bond beam or equivalent provides adequate resistance to moisture transport from a hollow core to the rim-joist cavity. Thus, a solid top course is a minimum requirement for an interior retrofit insulation system.

BASEMENT↗

DOE OSTI2015

Technology Solutions Case Study: Innovative Retrofit Foundation Insulation Strategies, Minneapolis, Minnesota

Basements in climates 6 & 7 can account for a fraction of a home's total heat loss when fully conditioned. These foundations are a source of moisture, with convection in open block cavities redistributing water from the wall base, usually when heating. Even when block cavities are capped, the cold foundation concrete can act as a moisture source for wood rim joist components that are in contact with the wall. As below-grade basements are increasingly retrofitted for habitable space, cold foundation walls pose increased challenges for moisture durability, energy use, and occupant comfort. To address this challenge, the NorthernSTAR Building America Partnership evaluated a retrofit insulation strategy for foundations that is designed for use with open-core concrete block foundation walls. The three main goals were to improve moisture control, improve occupant comfort, and reduce heat loss.

Building America↗

DOE OSTI2016

Building America Case Study: Optimized Slab-on-Grade Foundation Insulation Retrofits, Madison, Wisconsin

A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 percent for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2016

Mind the Gap: Summary of Window Residential Retrofit Solutions

Improving the insulation, solar heat gain, and infiltration characteristics of windows in a home has the potential to significantly improve the overall thermal performance by reducing heat transfer through the window and also by decreasing infiltration of outdoor air into the home. As approximately 43% of existing homes still have single-pane clear windows (~50 million houses) and millions of other homes have only double-pane clear windows (Cort 2013), improving window performance also presents a significant opportunity for energy savings in the residential sector. Today, various energy-saving window retrofit opportunities are available to homeowners, ranging from window coverings and storm panels to highly-insulating triple-pane R-5 window replacements. Many of these technologies have been evaluated in the field, in the “Lab Homes” at Pacific Northwest National Laboratory, and through modeling to prove their cost-effectiveness and performance in different climate regions. Recently, the Pacific Northwest’s Regional Technical Forum approved a utility measure for low- emissivity storm windows based on such data. This action represents a watershed moment for increasing the variety and prevalence of fenestration options in utility programs, especially for the low-income demographic. This paper will review various window retrofit options, the most recent field test and modeling data regarding their performance and cost-effectiveness, and discuss future rating efforts. This information is useful for utilities and energy-efficiency program managers to help effectively implement incentive measures for these technologies.

HVAC↗

DOE OSTI2020

Cost Assessment of Building Envelope Retrofits

About 65% of US buildings were constructed before the Department of Energy established the Building Energy Codes Program in 1992; therefore, their envelopes are likely significant contributors to heating and cooling loads. Numerous techniques to improve the thermal, airtightness, and water tightness performance of existing envelopes have been explored; however, these tend to be lengthy and disruptive because most of the material assembly occurs at the job site. Overclad panels that are fabricated offsite and include most of the envelope components are a potential mechanism to reduce construction time and minimize disturbance to building occupants. These benefits have been demonstrated by European programs such as Energiesprong and MORE-CONNECT, as well as a few case studies in the US. Nevertheless, preliminary evaluations appear to indicate that overclad panels may be too costly to be implemented in the US. This paper summarizes cost estimates, strengths and weaknesses from several envelope retrofit techniques; assesses the feasibility of overclad panels in the US; and proposes methods, such as advanced manufacturing techniques, that could decrease the cost of building envelope retrofits.

Salonvaara, Mikael↗

DOE OSTI2021

System and method for characterization of retrofit opportunities in building using data from communicating thermostats

Systems and methods for characterization of retrofit opportunities are described. The methods may comprise computing, using at least one computing device disposed remote from a building and based at least in part on heating, ventilation and air conditioning (HVAC) runtime data associated with the building, one or more thermal characteristics of the building. In some embodiments, a model-predicted indoor temperature may be fitted against thermal data measured by a thermostat at the building. The thermal characteristic of the building may comprise a thermal insulation, an air leakage rate and/or an HVAC efficiency. The method may be used to determine, using the at least one computing device, suitability of the building for a retrofit opportunity to improve energy efficiency of the building. Determining the suitability may comprise evaluating the one or more thermal characteristics. The HVAC runtime data may be computed based on data received from a thermostat or a meter, such as an electric or a gas meter.

Zeifman, Michael↗

DOE OSTI2021

System and method for characterization of retrofit opportunities in building using data from interval meters

Zeifman, Michael↗

DOE OSTI2021

Energy efficient soundproofing window retrofits

Described herein are window retrofits including a monolithic silica aerogel slab having (i) an average haze value of <5% as calculated in accordance with ASTM standard D1003-13 and (ii) a U-factor of <0.5 BTU/sf/hr/° F., and a transparent polymer envelope sealed at an internal pressure of ≤1 atmosphere, wherein the monolithic silica aerogel slab is encapsulated in the transparent polymer envelope. The monolithic aerogel slab can have a transmittance >94% at 8 mm thickness. The window retrofit can be bonded to a glass sheet.

Wang, Evelyn N.↗