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At least 199 records · Page 11

A Simplified Building Modeling Approach for Identifying Whole Building Retrofits

Building Energy Modeling (BEM) is an effective strategy for optimizing new and retrofit building design, evaluating its energy savings potential and rating its energy performance. However, because of the complexity and expense of modeling, only a small percentage of buildings are simulated. Over 80% of buildings are <25,000 ft2, and the cost associated with BEM can be a big deterrent for reaching this subsector, which usually ends up complying with energy codes and qualifying for incentives using prescriptive measures or generalized design guides. Similarly, efficiency considerations for small building retrofits are often identified through deemed measures or Technical Reference Manuals, which though a scalable and convenient approach, can limit innovation in design and optimization of measures. Simplification of the modeling process, where appropriate, can lead to increased energy savings and more informed decision making. This paper will discuss the development of a ruleset for a simplified approach based on the Performance Rating Method (PRM) contained in ASHRAE Standard 90.1. The approach aims to simplify and lower the cost of the energy modeling process in a controlled and documented manner. An anticipated outcome is an increased use of BEM and its effectiveness in the design, retrofit and operation of commercial buildings. In addition, simplification of the modeling process will result in fewer errors from misinterpretations of both program requirements and program intent in simulation software. The paper will discuss the need and advantages of a simplified modeling approach for whole building retrofits and the technical process for achieving the same.

Goel, Supriya↗

Scaling Deep Energy Retrofits for Residential Walls - Energy, Cost, and Economic Assessment of Five Wall Systems

Providing strong economic and performance value is a primary challenge of convincing homeowners to implement deep energy retrofits to their wall systems. This study combines energy modeling and technoeconomic assessment of six experimental residential retrofit wall systems to typical existing homes in cold climates to evaluate their energy performance and cost effectiveness. Deep energy retrofits can significantly improve the energy performance of a home’s thermal envelope, help manage indoor environmental pollutants, increase homeowner comfort, increase building value, and register significant energy and cost savings in the process. We are evaluating exterior wall retrofit components and construction practices to measure and recommend steps to improve financial performance for manufacturers, installers and consumers. This study leverages a literature review, inputs from an advisory group made up of thermal enclosure experts, and simulations to identify state-of-the-art technologies for energy efficient wall systems that are suitable for cold and very cold climate zones. This paper will present results from energy modeling of six experimental wall systems compared to one baseline, that inform cost and energy performance of the subject wall systems.

Ganguli, Sumitrra↗

Retrofitting NGCC and PC Power Plants with Carbon Capture Technology

This is a poster that was presented at the 2023 Carbon Management Research Project Review Meeting. The poster highlights primary takeaways from two reports that were recently released by NETL on retrofitting natural gas combined cycle (NGCC) and pulverized coal (PC) power plants with solvent-based carbon capture technology. The poster highlights the performance and cost of retrofitting these plants at 90 and 95% carbon capture, including consideration of cases that attempt to makeup for steam turbine derates caused by extracting steam for use in the capture process. Additionally, the poster highlights NETL's recently released carbon capture retrofit databases (CCRD) for both NGCC and PC plants. The CCRDs are public-facing tools that allow the end-user to approximate the incremental cost of CO2 capture for a user defined plant with retrofitted capture technology.

Hackett, Gregory↗

Housing Archetype Analysis for Home Energy-Efficient Retrofit in the Great Lakes Region

This project report details activities and results of the 'Market Characterization' project undertaken by the Cost Effective Energy Retrofit (CEER) team targeted toward the DOE goal of achieving 30%-50% reduction in existing building energy use. CEER consists of members from the Dow Chemical Company, Michigan State University, Ferris State University and Habitat for Humanity Kent County. The purpose of this market characterization project was to identify housing archetypes which are dominant within Great Lakes region and therefore offer significant potential for energy-efficient retrofit research and implementation due to the substantial number of homes possessing similar characteristics. Understanding the characteristics of housing groups referred to as 'archetypes' by vintage, style, and construction characteristics can allow research teams to focus their retrofit research and develop prescriptive solutions for those structure types which are prevalent and offer high potential uptake within a region or market. Key research activities included; literature review, statistical analysis of national and regional data of the American Housing Survey (AHS) collected by the U.S. Census Bureau, analysis of Michigan specific data, development of a housing taxonomy of architectural styles, case studies of two local markets (i.e., Ann Arbor and Grand Rapids in Michigan) and development of a suggested framework (or process) for characterizing local markets. In order to gain a high level perspective, national and regional data from the U.S. Census Bureau was analyzed using cross tabulations, multiple regression models, and logistic regression to characterize the housing stock and determine dominant house types using 21 variables.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Community-Scale Attic Retrofit and Home Energy Upgrade Data Mining

The U.S. Department of Energy’s Building America research team, Alliance for Residential Building Innovation (ARBI), implemented a project to increase residential retrofits in Davis, California. The project used a neighborhood-focused strategy for implementation and a low-cost retrofit program that focused on upgraded attic insulation and duct sealing. ARBI worked with a community partner, the not-for-profit Cool Davis Initiative, as well as selected area contractors to implement a strategy that sought to capitalize on the strong local expertise of partners and the unique aspects of the Davis, California, community. Working with community partners also allowed ARBI to collect and analyze data about effective messaging tactics for community-based retrofit programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Byggmeister Test Home: Analysis and Initial Results of Cold Climate Wood-Framed Home Retrofit

BSC seeks to further the energy efficiency market for New England area retrofit projects by supporting projects that are based on solid building science fundamentals that will benefit the homeowner through a combination of energy savings, improved durability, and occupant comfort. This report describes a deep retrofit project of a two-family wood-framed home in Belmont, Massachusetts, and examines the retrofit measures for the enclosure and mechanical systems and reviews the decision-making process that took place during planning.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Housing Archetype Analysis for Home Energy-Efficient Retrofit in the Great Lakes Region

This project report details activities and results of the "Market Characterization" project undertaken by the Cost Effective Energy Retrofit (CEER) team targeted toward the DOE goal of achieving 30%-50% reduction in existing building energy use. CEER consists of members from the Dow Chemical Company, Michigan State University, Ferris State University, and Habitat for Humanity Kent County. The purpose of this market characterization project was to identify housing archetypes which are dominant within the Great Lakes region and therefore offer significant potential for energy-efficient retrofit research and implementation due to the substantial number of homes possessing similar characteristics. Understanding the characteristics of housing groups referred to as "archetypes" by vintage, style, and construction characteristics can allow research teams to focus their retrofit research and develop prescriptive solutions for those structure types which are prevalent and offer high potential uptake within a region or market.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Building America Case Study: Retrofit Measure for Embedded Wood Members in Insulated Mass Masonry Walls, Lawrence, Massachusetts

?There are many existing buildings with load-bearing mass masonry walls, whose energy performance could be improved with the retrofit of insulation. However, adding insulation to the interior side of walls of such masonry buildings in cold (and wet) climates may cause performance and durability problems. Some concerns, such as condensation and freeze-thaw have known solutions. But wood members embedded in the masonry structure will be colder (and potentially wetter) after an interior insulation retrofit. Moisture content and relative humidity were monitored at joist ends in historic mass brick masonry walls retrofitted with interior insulation in a cold climate (Zone 5A); data were collected from 2012-2015. Eleven joist ends were monitored in all four orientations. One limitation of these results is that the renovation is still ongoing, with limited wintertime construction heating and no permanent occupancy to date. Measurements show that many joists ends remain at high moisture contents, especially at north- and east-facing orientations, with constant 100 percent RH conditions at the worst cases. These high moisture levels are not conducive for wood durability, but no evidence for actual structural damage has been observed. Insulated vs. non-insulated joist pockets do not show large differences. South facing joists have safe (10-15 percent) moisture contents. Given the uncertainty pointed out by research, definitive guidance on the vulnerability of embedded wood members is difficult to formulate. In high-risk situations, or when a very conservative approach is warranted, the embedded wood member condition can be eliminated entirely, supporting the joist ends outside of the masonry pocket.

BSC↗

Evaluation of Two CEDA Weatherization Pilot Implementations of an Exterior Insulation and Over-Clad Retrofit Strategy for Residential Masonry Buildings in Chicago

This project examines the implementation of an exterior insulation and over-clad strategy for brick masonry buildings in Chicago. The strategy was implemented at a free-standing two story two-family dwelling and a larger free-standing multifamily building. The test homes selected for this research represent predominant housing types for the Chicago area. High heating energy use typical in these buildings threaten housing affordability. Uninsulated mass masonry wall assemblies also have a strongly detrimental impact on comfort. Significant changes to the performance of masonry wall assemblies is generally beyond the reach of typical weatherization (Wx) program resources. The Community and Economic Development Association of Cook County, Inc. (CEDA) has secured a Sustainable Energy Resources for Consumers (SERC) innovation grant sponsored by the United States Department of Energy (DOE). This grant provides CEDA the opportunity to pursue a pilot implementation of innovative approaches to retrofit in masonry wall enclosures. The exterior insulation and over-clad strategy implemented through this project was designed to allow implementation by contractors active in CEDA weatherization programs and using materials and methods familiar to these contractors. The retrofit measures are evaluated in terms of feasibility, cost and performance. Through observations of the strategies implemented, the research described in this report identifies measures critical to performance as well as conditions for wider adoption. The research also identifies common factors that must be considered in determining whether the exterior insulation and over-clad strategy is appropriate for the building.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Evaluation of Two CEDA Weatherization Pilot Implementations of an Exterior Insulation and Over-Clad Retrofit Strategy for Residential Masonry Buildings in Chicago

This project examines the implementation of an exterior insulation and over-clad strategy for brick masonry buildings in Chicago—a free-standing two story two-family dwelling and a larger free-standing multifamily building. The test homes selected for this research represent predominant housing types for the Chicago area, in which high heating energy use typical in these buildings threaten housing affordability, and uninsulated mass masonry wall assemblies are uncomfortable for residents. In this project, the Community and Economic Development Association of Cook County, Inc. (CEDA) has secured a Sustainable Energy Resources for Consumers (SERC) innovation grant sponsored by DOE to pursue a pilot implementation of innovative approaches to retrofit in masonry wall enclosures. The retrofit measures are evaluated in terms of feasibility, cost and performance. Through observations of the strategies implemented, the research described in this report identifies measures critical to performance as well as conditions for wider adoption. The research also identifies common factors that must be considered in determining whether the exterior insulation and over-clad strategy is appropriate for the building.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

National Grid Deep Energy Retrofit Pilot

Through discussion of five case studies (test homes), this project evaluates strategies to elevate the performance of existing homes to a level commensurate with best-in-class implementation of high-performance new construction homes. The test homes featured in this research activity participated in Deep Energy Retrofit (DER) Pilot Program sponsored by the electric and gas utility National Grid in Massachusetts and Rhode Island. Building enclosure retrofit strategies are evaluated for impact on durability and indoor air quality in addition to energy performance.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Automatic generation and simulation of urban building energy models based on city datasets for city-scale building retrofit analysis

Buildings in cities consume 30–70% of total primary energy, and improving building energy efficiency is one of the key strategies towards sustainable urbanization. Urban building energy models (UBEM) can support city managers to evaluate and prioritize energy conservation measures (ECMs) for investment and the design of incentive and rebate programs. This paper presents the retrofit analysis feature of City Building Energy Saver (CityBES) to automatically generate and simulate UBEM using EnergyPlus based on cities’ building datasets and user-selected ECMs. CityBES is a new open web-based tool to support city-scale building energy efficiency strategic plans and programs. The technical details of using CityBES for UBEM generation and simulation are introduced, including the workflow, key assumptions, and major databases. Also presented is a case study that analyzes the potential retrofit energy use and energy cost savings of five individual ECMs and two measure packages for 940 office and retail buildings in six city districts in northeast San Francisco, United States. The results show that: (1) all five measures together can save 23–38% of site energy per building; (2) replacing lighting with light-emitting diode lamps and adding air economizers to existing heating, ventilation and air-conditioning (HVAC) systems are most cost-effective with an average payback of 2.0 and 4.3 years, respectively; and (3) it is not economical to upgrade HVAC systems or replace windows in San Francisco due to the city's mild climate and minimal cooling and heating loads. Furthermore, the CityBES retrofit analysis feature does not require users to have deep knowledge of building systems or technologies for the generation and simulation of building energy models, which helps overcome major technical barriers for city managers and their consultants to adopt UBEM.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

The impact of energy-efficiency upgrades and other distributed energy resources on a residential neighborhood-scale electrification retrofit

We report ambitious targets for carbon emissions reductions are highlighting new challenges for electrification strategies, leading to an increased focus on building load flexibility and energy management to complement the variability inherent in renewable energy generation. Over the next decade millions of existing homes could undergo electrification retrofits, and there is an urgent need to understand the potential impacts of electrifying major residential loads such as water and space heating on community load characteristics, resident energy bills, and the utility's distribution system. Behind-the-meter distributed energy resources (DERs), including efficiency measures, photovoltaics (PV), battery storage, managed electric vehicle (EV) charging, and controls such as home energy management systems (HEMS), can significantly alter a neighborhood's load profile and provide benefits to both the residents and the grid. We present a novel approach to characterizing the impact of a hypothetical neighborhood-scale residential retrofit program on individual homes' energy use profiles, associated utility bills, and the local distribution system. We modeled a mixed-fuel community of 30 single-family homes in Denver, Colorado, and compared the effects of retrofit scenarios ranging from conventional energy-efficiency upgrades to full electrification with and without more advanced DER technologies. We analyzed which packages of DERs most reliably enable demand flexibility in response to a time-of-use (TOU) rate for this and similar neighborhoods. Our buildings-to-grid co-simulation framework includes a generic secondary distribution feeder model to capture voltage profiles, transformer loading, and other grid impacts in each case. We also calculated the carbon emissions associated with energy use in the community. The methodology developed here can be broadly applied to community-scale beneficial electrification studies in other regions, climates, utility infrastructures, and building typologies to make specific, targeted recommendations based on quantified projections of energy demand in any given community. Our findings indicate that residential electrification can be achieved without negatively impacting the monthly utility bill, and that a combination of conventional energy-efficiency measures, PV, battery, controls, and managed EV charging to maximize a community's demand flexibility is a promising strategy. Adding DERs (especially PV) as part of efficient electrification produces much bigger savings than efficient electrification without DERs. A key barrier is that upgrades require upfront costs, and modest utility bill savings result in long payback periods.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Energy performance of an operational government building retrofitted with ceiling phase change material tiles in a mixed-humid climate

The aging U.S. building stock requires various retrofit measures to enhance their energy efficiency. Here, this study explores the integration of thermal energy storage and advanced building controls as viable retrofit solutions for load flexibility and peak demand response while maintaining the occupants' comfort. A detailed assessment is conducted on the energy use of an administrative building in Sumner County, Kansas, focusing on the implementation of phase change materials (PCMs) in the ceiling of occupied zones. First, a time-resolved, whole-building energy model is developed in EnergyPlus, incorporating complex thermal behaviors such as air exchange between the plenum space and occupied zones, envelope leakage, and operational schedules. The model is then validated using experimental field test data, and subsequently a parametric assessment of key PCM properties and application strategies is performed to evaluate cooling electricity demand benefits. The parametric study shows that the optimal retrofit strategy, comprising a PCM with 23°C peak melting temperature, 0.125 in. (3.17 mm) thickness, and 150 kJ/kg latent heat, combined with active controls that include 8 h of precooling, forced convection under the ceiling, and a 2°C thermostat setback during peak hours, can result in a maximum load shift during the peak period of 99.6 % and the total electricity savings during the peak period of 98.9 % for the optimum case and thus provide significant cost savings under time-of-use pricing scenarios.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Chamberlain Heights Redevelopment: A Large Scale, Cold Climate Study of Affordable Housing Retrofits

The City of Meriden Housing Authority (MHA) collaborated with affordable housing developer Jonathon Rose Companies (JRC) to complete a gut renovation of 124 residential units in the Chamberlain Heights retrofit project. The affordable housing community is made up of 36 buildings in duplex and quad configurations located on 22 acres within two miles of downtown Meriden, CT. The final post-retrofit analysis showed 40-45% source energy savings over the existing pre-retrofit conditions.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Post-Retrofit Residential Assessments

This study examined a range of factors influencing energy consumption in households that had participated in residential energy-efficiency upgrades. The study was funded by a grant from the U.S. Department of Energy’s Pacific Northwest National Laboratory and was conducted by faculty and staff of Portland State University Center for Urban Studies and Department of Economics. This work was made possible through the assistance and support of the Energy Trust of Oregon (ETO), whose residential energy-efficiency programs provided the population from which the sample cases were drawn. All households in the study had participated in the ETO Home Performance with Energy Star (HPwES) program. A number of these had concurrently pursued measures through other ETO programs. Post-retrofit energy outcomes are rarely investigated on a house-by-house basis. Rather, aggregate changes are ordinarily the focus of program impact evaluations, with deviation from aggregate expectations chalked up to measurement error, the vagaries of weather and idiosyncrasies of occupants. However, understanding how homes perform post-retrofit on an individual basis can give important insights to increase energy savings at the participant and the programmatic level. Taking a more disaggregated approach, this study analyzed energy consumption data from before and after the retrofit activity and made comparisons with engineering estimates for the upgrades, to identify households that performed differently from what may have been expected based on the estimates. A statistical analysis using hierarchal linear models, which accounted for weather variations, was performed looking separately at gas and electrical use during the periods before and after upgrades took place. A more straightforward comparison of billing data for 12-month periods before and after the intervention was also performed, yielding the majority of the cases examined. The later approach allowed total energy use and costs to be assessed but did not account for weather variation. From this statistical analysis, 18 study participants were selected and interviewed. The participants completed an in-home interview covering a range of topics, including changes in occupancy and additional changes to the homes that may have affected energy use. The goal of the interviews was to identify factors that may have contributed to unusual energy performance. These factors were identified by their frequency of occurrence in outperforming or underperforming homes, or simply by identifying factors that had the largest impact on overall savings. The motivations and levels of satisfaction with the outcomes of the upgrades were covered in detail, as well as extensive discussions of behaviors pertaining to thermal control, lighting, water, and appliance use. Most of cases studied achieved substantial energy savings, although it was more common for the projected savings to be greater than the demonstrated savings. Two factors that played a very large role in savings variation were 1) changes in occupancy and 2) fenestration improvements outside of the incentive programs. Motivation for pursuing the upgrades (e.g., environmental sustainability vs. comfort or cost savings) did not seem to play any role in achieving savings. Participants generally were more concerned with maintaining aesthetics through lighting than comfort through heating or cooling. They also seemed more likely to turn the lights off when leaving a room than to turn the heat off when leaving the home.

high performance homes↗

Retrofit Audits and Cost Estimates: A Look at Quality and Consistency

Retrofit NYC Block by Block is an outreach program targeting owners of one- to four-family homes, the most common building type in New York City, with more than 600,000 structures citywide. Administered by the Pratt Center for Community Development and implemented by four nonprofit, community based organizations, Block by Block connects residents, businesses, and religious and civic organizationsin predominantly low- and moderate-income neighborhoods with one or more of a half-dozen public and private financial incentive programs that facilitate energy-efficiency retrofits. This research project sought to evaluate the approach, effectiveness, and the energy use reductions accomplished by the Retrofit NYC: Block by Block program.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Cost-Effectiveness of Home Energy Retrofits in Pre-Code Vintage Homes in the United States

This analytical study examines the opportunities for cost-effective energy efficiency and renewable energy retrofits in residential archetypes constructed prior to 1980 (Pre-Code) in fourteen U.S. cities. These fourteen cities are representative of each of the International Energy Conservation Code (IECC) climate zones in the contiguous U.S. The analysis is conducted using an in-house version of EnergyGauge USA v.2.8.05 named CostOpt that has been programmed to perform iterative, incremental economic optimization on a large list of residential energy efficiency and renewable energy retrofit measures. The principle objectives of the study are as follows: to determine the opportunities for cost effective source energy reductions in this large cohort of existing residential building stock as a function of local climate and energy costs; and to examine how retrofit financing alternatives impact the source energy reductions that are cost effectively achievable.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗