Search NASA⌕ Search

SEARCH · Search NASA

Results for “payback”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Joining Techniques for Novel Metal Polymer Hybrid Heat Exchangers

In the United States, over 50% of the unrecovered energy from industrial processes is in the form of low-grade heat (< 220°C). Materials and maintenance costs of common heat exchangers are typically too high to justify their usage. Polymers, though more affordable, are usually unsuitable for HX applications due to their low thermal conductivity (~0.2 W/mK). Here, we show that metal-polymer hybrids may be attractive from both performance and cost perspectives. The use of polymers further increases the resistance to corrosion by sulfuric and carbonic acids often present in flue gases. An ongoing work explores different configurations of layered polyimide-copper macroscale hybrids for heat exchanger applications using numerical simulations. This paper explores a manufacturing pathway for producing such layered hybrid tubes that involves directly rolling and bonding tapes made of polymer and copper foil into tubes. A critical problem in the fabrication process is the bonding of metal and polymers. We explore approaches involving adhesives (epoxy, acrylic and silicone) for metal/polymer interfaces and direct welding (ultrasonic) for metal/metal interfaces that can be integrated into the manufacturing process. We report characterizations of the thermomechanical properties of these joining processes. This work paves the way for realizing cost-effective manufacturing of heat exchangers for low grade waste heat recovery.

Kuntumalla, Gowtham↗
DOE OSTI2014

Facility Energy Decision System (FEDS) version 7.0

Designed for building energy managers, utilities and firms providing energy services, FEDS provides a comprehensive and user-friendly method for users to quickly and accurately identifying energy conversion and end-use technology improvements that offer maximum savings in energy usage and cost. FEDS enables the user to assess energy efficiency and consumption, identify retrofit opportunities, select minimum life cycle costs, determine payback, and prioritize investments in energy efficiency retrofit projects for multiple or single buildings across a particular site. As part of the life-cycle cost optimization it also considers several options for partial or complete abandonment of central energy plants including: individual technologies dropping off a thermal loop, a loop and all technologies dropping off a central plant, and all technologies and loops dropping off a central plant resulting in its complete abandonment. Improvements in release 7.0 include: FEDS 7.0 is now a full hourly simulation model (runs every hour of the year as opposed to the previous simplified hourly approach which ran 9 24-hour periods to represent each month). Enhanced building operation and occupancy modeling; New HVAC technology options (VAV, Economizers, Demand Controlled Ventilation, Terminal Reheat, Subcool Dehumidification); Additional chiller types; New lighting technologies (LED, Halogen, Induction, additional fluorescent options); Completely updated retrofit cost and performance data; Regional cost data tied to zip code (previously applied state level averages); Updated and enhanced reporting capabilities; and New pier floor model

Dirks, James↗
DOE OSTI2017

Advanced Sorbent Structure Recovery of REEs, Precious Metals and Other Valuable Metals from Geothermal Waters and Its Associated Technoeconomics

This work evaluates, develops and demonstrates flexible, scalable mineral extraction technology for geothermal brines based upon solid phase sorbent materials with a specific focus upon rare earth elements (REEs). The selected organic and inorganic sorbent materials demonstrated high performance for collection of trace REEs, precious and valuable metals beyond commercially available sorbents. This report details the organic and inorganic sorbent uptake, performance, and collection efficiency results for La, Eu, Ho, Ag, Cu and Zn, as well as the characterization of these select sorbent materials. The report also contains estimated costs from an in-depth techno-economic analysis of a scaled up separation process. The estimated financial payback period for installing this equipment varies between 3.3 to 5.7 years depending on the brine flow rate of the geothermal resource.

15 GEOTHERMAL ENERGY↗
DOE OSTI2018

Overview of distributed energy storage for demand charge reduction

Utilities bill customers not only on energy use but peak power use since transmission costs are a function of power and not energy. Energy storage (ES) can deliver value to utility customers by leveling building demand and reducing demand charges. With increasing distributed energy generation and greater building demand variability, utilities have raised demand charges and are even including them in residential electricity bills. This paper will present a comprehensive overview of electrical and thermal energy storage technologies but will focus on mid-size energy storage technologies for demand charge avoidance in commercial and industrial applications. Of the ES technologies surveyed, lithium ion batteries deliver the highest value for demand charge reduction especially with systems that have larger power to energy ratios. Current lithium ion ES systems have payback periods below 5 years when deployed in markets with high demand charges.

25 ENERGY STORAGE↗
DOE OSTI2021

Energy Analysis: Ways to Save Energy and Reduce the Emissions in Wastewater Treatment Plants

The key of this study is to explore the primary energy consumers in wastewater treatment plants, which is considered as one of the major energy consumers, and introduces the best solution to save energy and reduce emissions in these facilities. This study is based on the energy assessment and analyses of eleven wastewater treatment plants. Through the investigation, it was found that plants can save up to 44,158 MWh of the energy consumption which is 47% from the total electricity consumption with a 17% reduction in the total utility bills and that about 2.5 million dollars cost savings after reviewing the currently facilitated energy system. Additionally, an average of five years' payback period resulted in most energy-saving recommendations. A vast potential of greenhouse gas emissions can be reduced with a total range reduction between 13 to 35 million kg of CO 2 based on the speed reduction percentage.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Case Study of a Californian Brewery to Potentially Use Concentrating Solar Power for Renewable Heat Generation

With the increasing relevance and acceptance of solar thermal for industrial process heat (IPH), a case study for a proposed concentrating solar power (CSP) integration into an existing Californian brewery is highlighted. The thermal generation from a 1 MWth solar field was modelled in the System Advisor Model (SAM), and the economics considered the viability of the project where different variables such as the installed solar field cost were investigated on metrics such as Net Present Value (NPV) and payback period. For the Base Case, without the 30% Investment Tax Credit (ITC), and using a 2017 Federal income tax rate of 35%, the project’s NPV reached $0 (i.e., the project becomes viable), when the installed solar field cost reached $158/m2. With the 30% ITC and 35% tax, the solar field installed cost is estimated at $324/m2 to obtain an NPV = $0. The biggest influences on project viability measured by NPV were the project life, Federal tax rate, and the solar field cost.

case study↗
DOE OSTI2013

Cayuga County Regional Digester: Vision Becomes Reality. Final Report

With an average herd size of 113 mature cows, Cayuga County is home to 280 dairy farms and 31,500 dairy milking cows producing approximately 855 million gallons of milk per year. The Cayuga Dairy industry is a major contributor to the countys economy, employing nearly 1200 people, while generating $140,000,000 of revenue from sale of milk alone. At the same time, the Cayuga County dairy industry also produces 5.7 million gallons of manure daily: (a) Nearly 34% of this manure is produced on smaller farms. (b) Digesters are expensive pieces of equipment and require attention and care. ( c) The on-farm digester systems have fairly long payback (>10 years) even for larger CAFO farms (>1000 milking cows). In 2005, Cayuga County Soil and Water Conservation District (The District), a Public Agency under Cayuga County, decided to undertake a centralized community digester project. The primary goal of the project was to develop an economically sustainable model, under the auspices of The District to address manure management issues facing the smaller dairies, improve the water quality and improve the quality of life for Cayuga County residents. It is believed that the District has accomplished this goal by completing construction of Cayuga County Regional Digester on a parcel of land behind the Cayuga County Natural Resource Center located at 7413 County House Road in the Town of Sennett in Cayuga County, New York. The digester facility consists of the following major components. 1. Transfer Station: This an indoor truck bay, where 35,000 gallons of manure from three local farms, 8,500 gallons of liquid organic food-processor waste, and 1,200 gallons of brown grease are unloaded from tanker trucks and the digested slurry is loaded onto the tanker trucks for delivery back to the participating farms. 2. Anaerobic Digester: The project utilizes a hydraulic mix anaerobic digester, a unique design that has no internal moving parts for mixing. The digester, which operates at mesophilic temperatures, is designed to process the daily feedstock and produce 220,000 SCF2 of biogas per day. The digester also produces 44,000 gallons of digested slurry per day. 3. Biogas Conditioning System: The plant employs a biological biogas conditioning system to remove the H2S and moisture contents of the biogas and prepare it to be used by the plant generation system. 4. Combined Heat and Power System (CHP): This is a 633kW high efficiency biogas-fired GE-Jenbacher model JMS-312 GS-NL reciprocating engine cogeneration system. The heat recovery system incorporated into the package is designed to capture the waste heat from the engine exhaust, the jacket cooling water and the engine oil circuit. 5. Electrical Substation and Power Distribution Systems: An electrical distribution system has been constructed on-site that aggregates the electrical service of the different county buildings on the District campus into a county owned electric distribution system that is interconnected with the CHP and the local electric grid. The electrical system is designed, in accordance with the utility guidelines, to allow grid-parallel operation of CHP and provide for import and export of electric power. 6. Thermal Energy Distribution System: The heat recovery system has been integrated into a high temperature water distribution system that distributes the heat to the thermal circuits for the anaerobic digester facility. Additional piping has also been installed to transfer the remaining thermal energy to other county buildings on the campus. On a daily basis, the plant will co-process 35,000 gallons of manure from local dairy farms, 8,500 gallons of food-processor waste and 1,200 gallons of brown grease to produce 200,000 ft3/d of biogas and 44,000 gallons of pathogen-free nutrient-rich digested slurry for agricultural use by farms and in the local area.The biogas fueled CHP produces 5,157,000 kWh of electricity and 19,506 dekatherms of thermal energy per year. Electrical power generated by the cogeneration system powers all the buildings on the Cayuga County campus and any surplus power is exported to the grid under a power purchase agreement. Heat recovered from the cogeneration system will be used to maintain the temperature of the process equipment and the excess will be transported to the Cayuga County Public Safety Building to offset purchase of fossil fuel to fuel the boilers. The majority of plant operations are unmanned and automated. However, the plant will have a small staff of well-trained personnel to coordinate the feedstock deliveries and shipments, supervise the day-to-day operation, monitor the systems and perform maintenance, maintain a safe and reliable operation and to respond to emergencies.

09 BIOMASS FUELS↗
DOE OSTI2013

Assessing Foundation Insulation Strategies for the 2012 International Energy Conservation Code in Cold Climate New Home Construction

Even though the International Energy Conservation Code 2012 (International Code Council 2012) is a model code now available for adoption by individual states, only two cold-climate states have adopted it as their new home energy code. Understanding the resistance to adoption is important in assisting more states to accept the code and engage in deep energy strategies nationwide. This three-part assessment by the NorthernSTAR Building America Partnership was focused on foundation insulation R-values for cold climates and the design, construction, and performance implications. In Section 1, a literature review and attendance at stakeholder meetings held in Minnesota were used to assess general stakeholder interest and concerns about proposed code changes. Section 2 includes drawings of robust foundation insulation systems that were presented at one Minnesota stakeholder meeting to address critical issues and concerns for adopting best practice strategies. In Section 3, a sampling of builders participated in a telephone interview to gain baseline knowledge on insulation systems used to meet the current energy code and how the same builders intend to meet the new proposed code. In general, most builders expressed interest in being able to deliver greater energy efficiency to their customers. Concerns were voiced, however, about the costs compared to the energy savings, constructability, and durability risk resulting from increased foundation insulation R-values. When solutions for building robust foundation wall systems were presented to stakeholders, they did express interest in learning the details of the strategies. There was, however, continued interest in proof of cost, payback, and hygrothermal performance. Builders who participated in the interview were more confident in being able to meet the new requirements. This might have been a result of these respondents already using more advanced techniques for foundation insulation. This insight gives Building America an opportunity to engage the industry with existing research and practice measures that can address constructability and durability concerns at the proposed code levels. It also indicates that builders are interested in more specific information on cost, energy savings, and overall hygrothermal performance. Filling these voids could yield the supportive data needed to enhance building industry confidence and engage more states in the adoption of 2012 International Energy Conservation Code for new homes.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Demonstration Assessment of Light-Emitting Diode Parking Structure Lighting at U.S. Department of Labor Headquarters

This report documents a solid-state lighting (SSL) technology demonstration at the parking structure of the U.S. Department of Labor (DOL) Headquarters in Washington, DC, in which light-emitting diode (LED) luminaires were substituted for the incumbent high-pressure sodium (HPS) luminaires and evaluated for relative light quantity and performance. The demonstration results show energy savings of 52% from the initial conversion of HPS to the LED product. These savings were increased to 88% by using occupancy sensor controls that were ultimately set to reduce power to 10% of high state operation after a time delay of 2.5 minutes. Because of the relatively high cost of the LED luminaires at their time of purchase for this project (2010), the simple payback periods were 6.5 years and 4.9 years for retrofit and new construction scenarios, respectively. Staff at DOL Headquarters reported high satisfaction with the operation of the LED product.

LEDs↗
DOE OSTI2013

Ultra-Efficient and Power Dense Electric Motors for U. S. Industry

The primary purpose of this project was to combine the ease-of-installation and ease-of-use attributes of industrial induction motors with the low-loss and small size and weight advantages of PM motors to create an ultra-efficient, high power density industrial motor that can be started across-the-line or operated from a standard, Volts/Hertz drive without the need for a rotor position feedback device. PM motor products that are currently available are largely variable speed motors that require a special adjustable speed drive with rotor position feedback. The reduced size and weight helps to offset the magnet cost in order make these motors commercially viable. The scope of this project covers horsepower ratings from 20 - 500. Prototypes were built and tested at ratings ranging from 30 to 250 HP. Since fans, pumps and compressors make up a large portion of industrial motor applications, the motor characteristics are tailored to those applications. Also, since there is extensive use of adjustable frequency inverters in these applications, there is the opportunity to design for an optimal pole number and operate at other than 60 Hz frequency when inverters are utilized. Designs with four and eight pole configurations were prototyped as part of this work. Four pole motors are the most commonly used configuration in induction motors today. The results of the prototype design, fabrication, and testing were quite successful. The 50 HP rating met all of the design goals including efficiency and power density. Tested values of motor losses at 50 HP were 30% lower than energy efficient induction motors and the motor weight is 35% lower than the energy efficient induction motor of the same rating. Further, when tested at the 30 HP rating that is normally built in this 286T frame size, the efficiency far exceeds the project design goals with 30 HP efficiency levels indicating a 55% reduction in loss compared to energy efficient motors with a motor weight that is a few percentage points lower than the energy efficient motor. This 30 HP rating full load efficiency corresponds to a 46% reduction in loss compared to a 30 HP NEMA Premium ® efficient motor. The cost goals were to provide a two year or shorter efficiency-based payback of a price premium associated with the magnet cost in these motors. That goal is based on 24/7 operation with a cost of electricity of 10 cents per kW-hr. Similarly, the 250 HP prototype efficiency testing was quite successful. In this case, the efficiency was maximized with a slightly less aggressive reduction in active material. The measured full load efficiency of 97.6% represents in excess of a 50% loss reduction compared to the equivalent NEMA Premium Efficiency induction motor. The active material weight reduction was a respectable 14.5% figure. This larger rating demonstrated both the scalability of this technology and also the ability to flexibly trade off power density and efficiency. In terms of starting performance, the 30 - 50 HP prototypes were very extensively tested. The demonstrated capability included the ability to successfully start a load with an inertia of 25 times the motor's own inertia while accelerating against a load torque following a fan profile at the motor's full nameplate power rating. This capability will provide very wide applicability of this motor technology. The 250 HP prototype was also tested for starting characteristics, though without a coupled inertia and load torque. As a result it was not definitively proven that the same 25 times the motor's own inertia could be started and synchronized successfully at 250 HP. Finite element modeling implies that this load could be successfully started, but it has not yet been confirmed by a test.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2013

Advanced Energy Retrofit Guide (AERG): Practical Ways to Improve Energy Performance; Healthcare Facilities (Book)

The Advanced Energy Retrofit Guide for Healthcare Facilities is part of a series of retrofit guides commissioned by the U.S. Department of Energy. By presenting general project planning guidance as well as detailed descriptions and financial payback metrics for the most important and relevant energy efficiency measures (EEMs), the guides provide a practical roadmap for effectively planning and implementing performance improvements in existing buildings. The Advanced Energy Retrofit Guides (AERGs) are intended to address key segments of the U.S. commercial building stock: retail stores, office buildings, K-12 schools, grocery stores, and healthcare facilities. The guides' general project planning considerations are applicable nationwide; the energy and cost savings estimates for recommended EEMs were developed based on energy simulations and cost estimates for an example hospital tailored to five distinct climate regions. These results can be extrapolated to other U.S. climate zones. Analysis is presented for individual EEMs, and for packages of recommended EEMs for two project types: existing building commissioning projects that apply low-cost and no-cost measures, and whole-building retrofits involving more capital-intensive measures.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Steam System Balancing and Tuning for Multifamily Residential Buildings in Chicagoland—Second Year of Data Collection

Steam heated buildings often suffer from uneven heating as a result of poor control of the amount of steam entering each radiator. In order to satisfy the heating load to the coldest units, other units are overheated. As a result, some tenants complain of being too hot and open their windows in the middle of winter, while others complain of being too cold and are compelled to use supplemental heat sources. Building on previous research, CNT Energy identified 10 test buildings in Chicago and conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam system balancing. A package of common steam balancing measures was assembled and data were collected on the buildings before and after these retrofits were installed to investigate the process, challenges, and the cost effectiveness of improving steam systems through improved venting and control systems. The test buildings that received venting upgrades and new control systems showed 10.2% savings on their natural gas heating load, with a simple payback of 5.1 years. The methodologies for and findings from this study are presented in detail in this report. This report has been updated from a version published in August 2012 to include natural gas usage information from the 2012 heating season and updated natural gas savings calculations.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Impacts of Water Quality on Residential Water Heating Equipment

Water heating is a ubiquitous energy use in all residential housing, accounting for 17.7% of residential energy use (EIA 2012). Today, there are many efficient water heating options available for every fuel type, from electric and gas to more unconventional fuel types like propane, solar, and fuel oil. Which water heating option is the best choice for a given household will depend on a number of factors, including average daily hot water use (total gallons per day), hot water draw patterns (close together or spread out), the hot water distribution system (compact or distributed), installation constraints (such as space, electrical service, or venting accommodations) and fuel-type availability and cost. While in general more efficient water heaters are more expensive than conventional water heating technologies, the savings in energy use and, thus, utility bills can recoup the additional upfront investment and make an efficient water heater a good investment over time in most situations, although the specific payback period for a given installation will vary widely. However, the expected lifetime of a water heater in a given installation can dramatically influence the cost effectiveness and savings potential of a water heater and should be considered, along with water use characteristics, fuel availability and cost, and specific home characteristics when selecting the optimum water heating equipment for a particular installation. This report provides recommendations for selecting and maintaining water heating equipment based on local water quality characteristics.

Corrosion↗
DOE OSTI2014

Small Town Energy Program (STEP) (Final Report revised)

University Park, Maryland (“UP”) is a small town of 2,540 residents, 919 homes, 2 churches, 1 school, 1 town hall, and 1 breakthrough community energy efficiency initiative: the Small Town Energy Program (“STEP”). STEP was developed with a mission to “create a model community energy transformation program that serves as a roadmap for other small towns across the U.S.” STEP first launched in January 2011 in UP and expanded in July 2012 to the neighboring communities of Hyattsville, Riverdale Park, and College Heights Estates, MD. STEP, which concluded in July 2013, was generously supported by a grant from the U.S. Department of Energy (DOE). The STEP model was designed for replication in other resource-constrained small towns similar to University Park - a sector largely neglected to date in federal and state energy efficiency programs. STEP provided a full suite of activities for replication, including: energy audits and retrofits for residential buildings, financial incentives, a community-based social marketing backbone and local community delivery partners. STEP also included the highly innovative use of an “Energy Coach” who worked one-on-one with clients throughout the program. Please see www.smalltownenergy.org for more information. In less than three years, STEP achieved the following results in University Park: • 30% of community households participated voluntarily in STEP; • 25% of homes received a Home Performance with ENERGY STAR assessment; • 16% of households made energy efficiency improvements to their home; • 64% of households proceeded with an upgrade after their assessment; • 9 Full Time Equivalent jobs were created or retained, and 39 contractors worked on STEP over the course of the project. Estimated Energy Savings - Program Totals kWh Electricity 204,407 Therms Natural Gas 24,800 Gallons of Oil 2,581 Total Estimated MMBTU Saved (Source Energy) 5,474 Total Estimated Annual Energy Cost Savings $\$61,343$ STEP clients who had a home energy upgrade invested on average $\$4,500$, resulting in a 13% reduction in annual energy use and utility bill savings of $325. Rebates and incentives covered 40%-50% of retrofit cost, resulting in an average simple payback of about 7 years. STEP has created a handbook in which are assembled all the key elements that went into the design and delivery of STEP. The target audiences for the handbook include interested citizens, elected officials and municipal staff who want to establish and run their own efficiency program within a small community or neighborhood, using elements, materials and lessons from STEP.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

High Efficiency Integrated Package

Solid-state lighting based on LEDs has emerged as a superior alternative to inefficient conventional lighting, particularly incandescent. LED lighting can lead to 80 percent energy savings; can last 50,000 hours – 2-50 times longer than most bulbs; and contains no toxic lead or mercury. However, to enable mass adoption, particularly at the consumer level, the cost of LED luminaires must be reduced by an order of magnitude while achieving superior efficiency, light quality and lifetime. To become viable, energy-efficient replacement solutions must deliver system efficacies of ≥ 100 lumens per watt (LPW) with excellent color rendering (CRI > 85) at a cost that enables payback cycles of two years or less for commercial applications. This development will enable significant site energy savings as it targets commercial and retail lighting applications that are most sensitive to the lifetime operating costs with their extended operating hours per day. If costs are reduced substantially, dramatic energy savings can be realized by replacing incandescent lighting in the residential market as well. In light of these challenges, Cree proposed to develop a multi-chip integrated LED package with an output of > 1000 lumens of warm white light operating at an efficacy of at least 128 LPW with a CRI > 85. This product will serve as the light engine for replacement lamps and luminaires. At the end of the proposed program, this integrated package was to be used in a proof-of-concept lamp prototype to demonstrate the component’s viability in a common form factor. During this project Cree SBTC developed an efficient, compact warm-white LED package with an integrated remote color down-converter. Via a combination of intensive optical, electrical, and thermal optimization, a package design was obtained that met nearly all project goals. This package emitted 1295 lm under instant-on, room-temperature testing conditions, with an efficacy of 128.4 lm/W at a color temperature of ~2873K and 83 CRI. As such, the package’s performance exceeds DOE’s warm-white phosphor LED efficacy target for 2013. At the end of the program, we assembled an A19 sized demonstration bulb housing the integrated package which met Energy Star intensity variation requirements. With further development to reduce overall component cost, we anticipate that an integrated remote converter package such as developed during this program will find application in compact, high-efficacy LED-based lamps, particularly those requiring omnidirectional emission.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina (Fact Sheet)

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques - manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the use of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $\$ $275 to $\$ $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Air Distribution Retrofit Strategies for Affordable Housing

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques -- manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the use of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Characterization of Energy Savings and Thermal Comfort Improvements Derived from Using Interior Storm Windows

This field study of a single historic home in Seattle, WA documents the performance of Indow ® Windows’s interior storm window inserts. Energy use and the temperature profile of the house were monitored before and after the installation of the window inserts and changes in the two recorded metrics were examined. Using the defined analysis approach, it was determined that the interior storm windows produced a 22% reduction of the HVAC energy bill and had an undetermined effect on the thermal comfort in the house. Although there was no measurable changes in the thermal comfort of the house, the occupant noted the house to be “warmer in the winter and cooler in the summer” and that the “temperatures are more even (throughout the house).” The interior storm windows were found to be not cost effective, largely due to the retrofits completed on its heating system. However, if the economic analysis was conducted based on the old heating system, a 72% efficient oil fired furnace, the Indow Windows proved to be economical and had a simple payback period of 9.0 years.

high performance housing↗