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Air Source Integrated Heat Pump For Near Zero Energy Houses
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Book Synopsis Air-Source Integrated Heat Pump for Near-Zero Energy Houses by :
Download or read book Air-Source Integrated Heat Pump for Near-Zero Energy Houses written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the development of an air-source integrated heat pump (AS-IHP) through the third quarter of FY2007. It describes the design, analyses and testing of the AS-IHP, and provides performance specifications for a field test prototype and proposed control strategy. The results obtained so far continue to support the AS-IHP being a promising candidate to meet the energy service needs for DOE's development of a Zero Energy Home (ZEH) by the year 2020.
Book Synopsis Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes -- Update to Include Analyses of an Economizer Option and Alternative Winter Water Heating Control Option by : Van David Baxter
Download or read book Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes -- Update to Include Analyses of an Economizer Option and Alternative Winter Water Heating Control Option written by Van David Baxter and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment, ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. In 2006, the two top-ranked options from the 2005 study, air-source and ground-source versions of an integrated heat pump (IHP) system, were subjected to an initial business case study. The IHPs were subjected to a more rigorous hourly-based assessment of their performance potential compared to a baseline suite of equipment of legally minimum efficiency that provided the same heating, cooling, water heating, demand dehumidification, and ventilation services as the IHPs. Results were summarized in a project report, Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes, ORNL/TM-2006/130 (Baxter 2006). The present report is an update to that document. Its primary purpose is to summarize results of an analysis of the potential of adding an outdoor air economizer operating mode to the IHPs to take advantage of free cooling (using outdoor air to cool the house) whenever possible. In addition it provides some additional detail for an alternative winter water heating/space heating (WH/SH) control strategy briefly described in the original report and corrects some minor errors.
Book Synopsis Ground-Source Integrated Heat Pump for Near-Zero Energy Houses by :
Download or read book Ground-Source Integrated Heat Pump for Near-Zero Energy Houses written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy service needs of a net-zero-energy house (ZEH) include space heating and cooling, water heating, ventilation, dehumidification, and humidification, depending on the requirements of the specific location. These requirements differ in significant ways from those of current housing. For instance, the most recent DOE buildings energy data (DOE/BED 2007) indicate that on average (almost equal to)43% of residential buildings primary energy use is for space heating and cooling, vs. (almost equal to)12% for water heating (about a 3.6:1 ratio). In contrast, for the particular prototype ZEH structures used in the analyses in this report, that ratio ranges from about 0.3:1 to 1.6:1 depending on location. The high-performance envelope of a ZEH results in much lower space heating and cooling loads relative to current housing and also makes the house sufficiently air-tight to require mechanical ventilation for indoor air quality. These envelope characteristics mean that the space conditioning load will be closer in size to the water heating load, which depends on occupant behavior and thus is not expected to drop by any significant amount because of an improved envelope. In some locations such as the Gulf Coast area, additional dehumidification will almost certainly be required during the shoulder and cooling seasons. In locales with heavy space heating needs, supplemental humidification may be needed because of health concerns or may be desired for improved occupant comfort. The U.S. Department of Energy (DOE) has determined that achieving their ZEH goal will require energy service equipment that can meet these needs while using 50% less energy than current equipment. One promising approach to meeting this requirement is through an integrated heat pump (IHP) - a single system based on heat pumping technology. The energy benefits of an IHP stem from the ability to utilize otherwise wasted energy; for example, heat rejected by the space cooling operation can be used for water heating. With the greater energy savings the cost of the more energy efficient components required for the IHP can be recovered more quickly than if they were applied to individual pieces of equipment to meet each individual energy service need. An IHP can be designed to use either outdoor air or geothermal resources (e.g., ground, ground water, surface water) as the environmental energy source/sink. Based on a scoping study of a wide variety of possible approaches to meeting the energy service needs for a ZEH, DOE selected the IHP concept as the most promising and has supported research directed toward the development of both air- and ground-source versions. This report describes the ground-source IHP (GS-IHP) design and includes the lessons learned and best practices revealed by the research and development (R & D) effort throughout. Salient features of the GS-IHP include a variable-speed rotary compressor incorporating a brushless direct current permanent magnet motor which provides all refrigerant compression, a variable-speed fan for the indoor section, a multiple-speed ground coil circuit pump, and a single-speed pump for water heating operation. Laboratory IHP testing has thus far used R-22 because of the availability of the needed components that use this refrigerant. It is expected that HFC R-410A will be used for any products arising from the IHP concept. Data for a variable-speed compressor that uses R-410A has been incorporated into the DOE/ORNL Mark VI Heat Pump Design Model (HPDM). HPDM was then linked to TRNSYS, a time-series-dependent simulation model capable of determining the energy use of building cooling and heating equipment as applied to a defined house on a sub-hourly basis. This provided a highly flexible design analysis capability for advanced heat pump equipment; however, the program also took a relatively long time to run. This approach was used with the initial prototype design reported in Murphy et al. (2007a) and in the business case analysis of Baxter (2007).
Book Synopsis Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Business Case Assessment by :
Download or read book Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Business Case Assessment written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft2 houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, 'HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment', ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. Table 1 summarizes the energy savings potential of the highest scoring options from the 2005 study for all five locations. All system options were scored by the ORNL building equipment research team and by William Goetzler of Navigant Consulting. These scores were reviewed by DOE/BT's Residential Integration program leaders and Building America team members. Based on these results, the two centrally ducted integrated heat pump (IHP) systems (air source and ground source versions) were selected for advancement to Stage 2 (Exploratory Development) business case assessments in FY06. This report describes results of these business case assessments. It is a compilation of three separate reports describing the initial business case study (Baxter 2006a), an update to evaluate the impact of an economizer cooling option (Baxter 2006b), and a second update to evaluate the impact of a winter humidification option (Baxter 2007). In addition it reports some corrections made subsequent to release of the first two reports to correct some errors in the TRNSYS building model for Atlanta and in the refrigerant pressure drop calculation in the water-to-refrigerant evaporator module of the ORNL Heat Pump Design Model (HPDM) used for the IHP analyses. These changes resulted in some minor differences between IHP performance as reported in Baxter (2006a, b) and in this report.
Book Synopsis Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes by : Van David Baxter
Download or read book Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes written by Van David Baxter and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. Although the energy efficiency of heating, ventilating, and air-conditioning (HVAC) equipment has increased substantially in recent years, new approaches are needed to continue this trend. Dramatic efficiency improvements are necessary to enable progress toward the NZEH goals, and will require a radical rethinking of opportunities to improve system performance. The large reductions in HVAC energy consumption necessary to support the NZEH goals require a systems-oriented analysis approach that characterizes each element of energy consumption, identifies alternatives, and determines the most cost-effective combination of options. In particular, HVAC equipment must be developed that addresses the range of special needs of NZEH applications in the areas of reduced HVAC and water heating energy use, humidity control, ventilation, uniform comfort, and ease of zoning. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft{sup 2} houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, 'HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment, ' ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. Table 1 summarizes the energy savings potential of the highest scoring options from the 2005 study for all five locations.
Book Synopsis Heat Pump Concepts for NZEB Technology Developments, Design Tools and Testing of Heat Pump Systems for NZEB in the USA by :
Download or read book Heat Pump Concepts for NZEB Technology Developments, Design Tools and Testing of Heat Pump Systems for NZEB in the USA written by and published by . This book was released on 2015 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IEA HPT Annex 40 "Heat pump concepts for Nearly Zero Energy Buildings" deals with the application of heat pumps as a core component of the HVAC system for Nearly or Net Zero energy buildings (nZEB). This report covers Task 2 on the system comparison and optimisation and Task 3 dedicated to the development of adapted technologies for nZEB and field monitoring results of heat pump systems in nZEB. In the US team three institutions are involved and have worked on the following projects: The Oak Ridge National Laboratory (ORNL) will summarize development activities through the field demonstration stage for several integrated heat pump (IHP) systems electric ground-source (GS-IHP) and air-source (AS-IHP) versions and an engine driven AS-IHP version. The first commercial GS-IHP product was just introduced to the market in December 2012. This work is a contribution to Task 3 of the Annex. The University of Maryland will contribute a software development project to Task 2 of the Annex. The software ThermCom evaluates occupied space thermal comfort conditions accounting for all radiative and convective heat transfer effects as well as local air properties. The National Institute of Standards and Technology (NIST) is working on a field study effort on the NIST Net Zero Energy Residential Test Facility (NZERTF). This residential building was constructed on the NIST campus and officially opened in summer 2013. During the first year, between July 2013 and June 2014, baseline performance of the NZERTF was monitored under a simulated occupancy protocol. The house was equipped with an air-to-air heat pump which included a dedicated dehumidification operating mode. Outdoor conditions, internal loads and modes of heat pump operation were monitored. Field study results with respect to heat pump operation will be reported and recommendations on heat pump optimization for a net zero energy building will be provided. This work is a contribution to Task 3 of the Annex.
Book Synopsis Active House: Smart Nearly Zero Energy Buildings by : Lone Feifer
Download or read book Active House: Smart Nearly Zero Energy Buildings written by Lone Feifer and published by Springer. This book was released on 2018-06-14 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides an overview of the Active House (AH) vision, intended as a building design method “beyond” the passive approach for buildings of the future that will be more and more connected, smart and innovative. It offers a novel philosophical design approach in which buildings, new or renovated, are in balance with natural, renewable energies and become “concentrators-distributors” of energies instead of being consumers of resources. The book is composed of five chapters, providing information on fundamental aspects of innovations toward resource-efficient buildings, as well as case studies presenting the concept in practice. It demonstrates that a completely new design approach is possible, and that a turning point has been reached. Lastly, it shows how the AH Alliance, along with designers, institutions, industries and academies, is bringing a breath of fresh air to the world of construction.
Book Synopsis Zero and Net Zero Energy by : Getu Hailu
Download or read book Zero and Net Zero Energy written by Getu Hailu and published by BoD – Books on Demand. This book was released on 2019-11-13 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a growing concern about fluctuating energy prices, energy security, and the impact of climate change. Buildings are amongst the primary energy consumers in the world. This fact underlines the importance of targeting building energy use as a key to decreasing any nation's energy consumption. According to the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) Research Strategic Plan 2010-2015, even limited deployment of Net-Zero-Energy buildings within this timeframe will have a beneficial effect by reducing the pressure for additional energy and power supply and the reduction of GHG emissions. The building sector is poised to significantly reduce energy use by incorporating energy-efficient strategies into the design, construction, and operation of new buildings and retrofits to improve the efficiency of existing buildings.
Book Synopsis Solar Engineering of Thermal Processes, Photovoltaics and Wind by : John A. Duffie
Download or read book Solar Engineering of Thermal Processes, Photovoltaics and Wind written by John A. Duffie and published by John Wiley & Sons. This book was released on 2020-03-24 with total page 930 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bible of solar engineering that translates solar energy theory to practice, revised and updated The updated Fifth Edition of Solar Engineering of Thermal Processes, Photovoltaics and Wind contains the fundamentals of solar energy and explains how we get energy from the sun. The authors—noted experts on the topic—provide an introduction to the technologies that harvest, store, and deliver solar energy, such as photovoltaics, solar heaters, and cells. The book also explores the applications of solar technologies and shows how they are applied in various sectors of the marketplace. The revised Fifth Edition offers guidance for using two key engineering software applications, Engineering Equation Solver (EES) and System Advisor Model (SAM). These applications aid in solving complex equations quickly and help with performing long-term or annual simulations. The new edition includes all-new examples, performance data, and photos of current solar energy applications. In addition, the chapter on concentrating solar power is updated and expanded. The practice problems in the Appendix are also updated, and instructors have access to an updated print Solutions Manual. This important book: • Covers all aspects of solar engineering from basic theory to the design of solar technology • Offers in-depth guidance and demonstrations of Engineering Equation Solver (EES) and System Advisor Model (SAM) software • Contains all-new examples, performance data, and photos of solar energy systems today • Includes updated simulation problems and a solutions manual for instructors Written for students and practicing professionals in power and energy industries as well as those in research and government labs, Solar Engineering of Thermal Processes, Fifth Edition continues to be the leading solar engineering text and reference.
Book Synopsis Net zero energy buildings by : Karsten Voss
Download or read book Net zero energy buildings written by Karsten Voss and published by Walter de Gruyter. This book was released on 2012-12-10 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Net zero energy buildings, equilibrium buildings or carbon neutral cities – depending on location and the reasons for making the calculation, the numbers are run differently. The variety of terms in use indicates that a scientific method is still lacking – which is a problem not just in regard to international communication, but also with respect to planning processes as a response to energy challenges. The clarification and meaning of the most important terms in use is extremely important for their implementation. Since October 2008, a panel of experts from an international energy agency has concerned itself with these topics as part of a project entitled “Towards Net Zero Energy Solar Buildings”. The objective is to analyse exemplary buildings that are near a zero-energy balance in order to develop methods and tools for the planning, design and operation of such buildings. The results are documented in this publication: In addition to the presentation of selected projects, it is not just architectural showcase projects that are shown – the focus is on relaying knowledge and experience gained by planners and builders. Even if many questions remain unanswered: Project examples that have already been implemented prove on a practical basis that the objective of a zero energy balance is already possible today."
Book Synopsis Compact Heat Exchangers by : J.E. Hesselgreaves
Download or read book Compact Heat Exchangers written by J.E. Hesselgreaves and published by Elsevier. This book was released on 2001-05-08 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the ideas and industrial concepts in compact heat exchanger technology that have been developed in the last 10 years or so. Historically, the development and application of compact heat exchangers and their surfaces has taken place in a piecemeal fashion in a number of rather unrelated areas, principally those of the automotive and prime mover, aerospace, cryogenic and refrigeration sectors. Much detailed technology, familiar in one sector, progressed only slowly over the boundary into another sector. This compartmentalisation was a feature both of the user industries themselves, and also of the supplier, or manufacturing industries. These barriers are now breaking down, with valuable cross-fertilisation taking place. One of the industrial sectors that is waking up to the challenges of compact heat exchangers is that broadly defined as the process sector. If there is a bias in the book, it is towards this sector. Here, in many cases, the technical challenges are severe, since high pressures and temperatures are often involved, and working fluids can be corrosive, reactive or toxic. The opportunities, however, are correspondingly high, since compacts can offer a combination of lower capital or installed cost, lower temperature differences (and hence running costs), and lower inventory. In some cases they give the opportunity for a radical re-think of the process design, by the introduction of process intensification (PI) concepts such as combining process elements in one unit. An example of this is reaction and heat exchange, which offers, among other advantages, significantly lower by-product production.To stimulate future research, the author includes coverage of hitherto neglected approaches, such as that of the Second Law (of Thermodynamics), pioneered by Bejan and co- workers. The justification for this is that there is increasing interest in life-cycle and sustainable approaches to industrial activity as a whole, often involving exergy (Second Law) analysis. Heat exchangers, being fundamental components of energy and process systems, are both savers and spenders of exergy, according to interpretation.
Book Synopsis Heating and Cooling with a Heat Pump by : Canada. Office of Energy Efficiency
Download or read book Heating and Cooling with a Heat Pump written by Canada. Office of Energy Efficiency and published by . This book was released on 2004 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Begins with a general description of heat pumps and how they work, their terminology, and their standards. This is followed by details on air- and ground-source heat pumps, including their operation, components, energy efficiency considerations, sizing and design considerations, installation, benefits, maintenance, operating costs, and life expectancy. Heating energy costs are then compared for heat pump and electric heating systems at various locations in Canada. Related equipment such as supplementary heating systems, thermostats, and heat distribution systems is also reviewed. Finally, answers are provided to some commonly asked questions about heat pumps.
Book Synopsis Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Update to Include Evaluation of Impact of Including a Humidifier Option by :
Download or read book Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes - Update to Include Evaluation of Impact of Including a Humidifier Option written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long range strategic goal of the Department of Energy's Building Technologies (DOE/BT) Program is to create, by 2020, technologies and design approaches that enable the construction of net-zero energy homes at low incremental cost (DOE/BT 2005). A net zero energy home (NZEH) is a residential building with greatly reduced needs for energy through efficiency gains, with the balance of energy needs supplied by renewable technologies. While initially focused on new construction, these technologies and design approaches are intended to have application to buildings constructed before 2020 as well resulting in substantial reduction in energy use for all building types and ages. DOE/BT's Emerging Technologies (ET) team is working to support this strategic goal by identifying and developing advanced heating, ventilating, air-conditioning, and water heating (HVAC/WH) technology options applicable to NZEHs. In FY05 ORNL conducted an initial Stage 1 (Applied Research) scoping assessment of HVAC/WH systems options for future NZEHs to help DOE/BT identify and prioritize alternative approaches for further development. Eleven system concepts with central air distribution ducting and nine multi-zone systems were selected and their annual and peak demand performance estimated for five locations: Atlanta (mixed-humid), Houston (hot-humid), Phoenix (hot-dry), San Francisco (marine), and Chicago (cold). Performance was estimated by simulating the systems using the TRNSYS simulation engine (Solar Energy Laboratory et al. 2006) in two 1800-ft2 houses--a Building America (BA) benchmark house and a prototype NZEH taken from BEopt results at the take-off (or crossover) point (i.e., a house incorporating those design features such that further progress towards ZEH is through the addition of photovoltaic power sources, as determined by current BEopt analyses conducted by NREL). Results were summarized in a project report, HVAC Equipment Design options for Near-Zero-Energy Homes--A Stage 2 Scoping Assessment, ORNL/TM-2005/194 (Baxter 2005). The 2005 study report describes the HVAC options considered, the ranking criteria used, and the system rankings by priority. In 2006, the two top-ranked options from the 2005 study, air-source and ground-source versions of a centrally ducted integrated heat pump (IHP) system, were subjected to an initial business case study. The IHPs were subjected to a more rigorous hourly-based assessment of their performance potential compared to a baseline suite of equipment of legally minimum efficiency that provided the same heating, cooling, water heating, demand dehumidification, and ventilation services as the IHPs. Results were summarized in a project report, Initial Business Case Analysis of Two Integrated Heat Pump HVAC Systems for Near-Zero-Energy Homes, ORNL/TM-2006/130 (Baxter 2006a). The present report is an update to that document which summarizes results of an analysis of the impact of adding a humidifier to the HVAC system to maintain minimum levels of space relative humidity (RH) in winter. The space RH in winter has direct impact on occupant comfort and on control of dust mites, many types of disease bacteria, and 'dry air' electric shocks. Chapter 8 in ASHRAE's 2005 Handbook of Fundamentals (HOF) suggests a 30% lower limit on RH for indoor temperatures in the range of (almost equal to)68-69F based on comfort (ASHRAE 2005). Table 3 in chapter 9 of the same reference suggests a 30-55% RH range for winter as established by a Canadian study of exposure limits for residential indoor environments (EHD 1987). Harriman, et al (2001) note that for RH levels of 35% or higher, electrostatic shocks are minimized and that dust mites cannot live at RH levels below 40%. They also indicate that many disease bacteria life spans are minimized when space RH is held within a 30-60% range. From the foregoing it is reasonable to assume that a winter space RH range of 30-40% would be an acceptable compromise between comfort considerations and limitation of growth rates for dust mites and many bacteria. In addition it reports some corrections made to the simulation models used in order to correct some errors in the TRNSYS building model for Atlanta and in the refrigerant pressure drop calculation in the water-to-refrigerant evaporator module of the ORNL Heat Pump Design Model (HPDM) used for the IHP analyses. These changes resulted in some minor differences between IHP performance as reported in Baxter (2006) and in this report.
Book Synopsis Thermal Energy Storage for the NIST Net-zero House Heat Pump by : M. A. Kedzierski
Download or read book Thermal Energy Storage for the NIST Net-zero House Heat Pump written by M. A. Kedzierski and published by . This book was released on 2018 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report investigates the viability of thermal energy storage by using a phase-change material (PCM) for residential air-conditioning. The air-conditioning performance and the associated external and internal heat loads to the National Institute of Standards and Technology's Net-Zero Energy Residential Test Facility (NZERTF) were modelled for a single day near the summer solstice. The transient model predicted the frequency and the duration of the cooling cycles for the air-source heat pump with and without PCM. The model was used to examine two different PCM energy storage configurations for their efficacy in improving energy efficiency and/or in meeting the entire peak cooling load for the house. The first configuration limited the mass of the PCM to minimize the required changes to a conventional cooling system. The main component of the first type of cooling system was the integrated PCM evaporator, where a limited amount of PCM was made an integral part of the evaporator and placed within an annulus that surrounded the refrigerant tube. The system with the integral PCM evaporator showed no potential advantage over a conventional system with a larger evaporator and a smaller compressor. The system with the integral PCM evaporator also failed to deliver improved energy savings and peak load shifting due to insufficient amount of PCM and a significant resistance to heat transfer through the PCM within the annulus. In contrast, the second configuration for the residential cooling system, which used remotely stored PCM, exhibited significant energy savings while shifting the entire peak thermal building load to the PCM energy storage with minimal electricity used during the peak load. The remote PCM system achieved between a 6 % and a 33 % reduction in the required electrical energy for the entire cooling day, depending on the PCM thermal resistance, while maintaining acceptable indoor humidity ratios. The performance was best when the heat transfer resistance between the PCM and the evaporating refrigerant was minimized.
Book Synopsis Advances in Ground-Source Heat Pump Systems by : Simon Rees
Download or read book Advances in Ground-Source Heat Pump Systems written by Simon Rees and published by Woodhead Publishing. This book was released on 2016-05-13 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Ground-Source Heat Pump Systems relates the latest information on source heat pumps (GSHPs), the types of heating and/or cooling systems that transfer heat from, or to, the ground, or, less commonly, a body of water. As one of the fastest growing renewable energy technologies, they are amongst the most energy efficient systems for space heating, cooling, and hot water production, with significant potential for a reduction in building carbon emissions. The book provides an authoritative overview of developments in closed loop GSHP systems, surface water, open loop systems, and related thermal energy storage systems, addressing the different technologies and component methods of analysis and optimization, among other subjects. Chapters on building integration and hybrid systems complete the volume. - Provides the geological aspects and building integration covered together in one convenient volume - Includes chapters on hybrid systems - Presents carefully selected chapters that cover areas in which there is significant ongoing research - Addresses geothermal heat pumps in both heating and cooling modes
Book Synopsis Heat Pumps for Sustainable Heating and Cooling by : Y. H. Venus Lun
Download or read book Heat Pumps for Sustainable Heating and Cooling written by Y. H. Venus Lun and published by Springer Nature. This book was released on 2019-11-13 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the significance of using sustainable energy to prevent the deterioration of our planet using heat pumps. Energy sustainability can be achieved through improved energy efficiency. In this regard, heat pumps offer an energy-efficient alternative for heating and cooling. To drive the adoption of heat pumps as a key component of sustainable buildings, the authors focus on examining sustainable practices in heat pump operations and innovative system design. In view of the growing desire to use sustainable energy to meet heating and cooling demands and improve indoor air quality, this book offers a valuable reference guide to the available options in HVAC (heating, ventilation, and air-conditioning) system design. To begin with, the authors define sustainable energy and discuss the trend of “thinking green” in building design. They then discuss sustainable practices and heat pump applications in mapping out HVAC systems. In turn, they examine the use of green operations to promote sustainable practices and, in order to highlight the importance of innovative design, discuss the configuration options and precision control aspects. In closing, the authors illustrate innovative sustainable design on the basis of several energy-efficient cases. The book’s main goal is to drive the adoption of sustainable energy solutions. Heat pumps, it argues, represent the most efficient system for meeting commercial/recreational/residential heating and cooling demands. The book not only examines industrial practices in heat pump application, but also discusses advanced heat pump technologies and innovative heat pump designs.
Book Synopsis A Side-by-side Energy Use Comparison of a Variable-speed Small Duct High Velocity and Two-stage Conventional Ducted Heat Pump in a Net-zero Energy Home by : W. Vance Payne
Download or read book A Side-by-side Energy Use Comparison of a Variable-speed Small Duct High Velocity and Two-stage Conventional Ducted Heat Pump in a Net-zero Energy Home written by W. Vance Payne and published by . This book was released on 2020 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two air-source, split system heat pumps were installed in a residential, net-zero energy home that was constructed as a laboratory on the campus of the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland USA. The first heat pump was a two-stage, 7 kW (2 ton), 15.8 seasonal energy efficiency ratio (SEER), 9.05 heating seasonal performance ratio (HSPF) conventionally ducted system, and the second heat pump was a variable-speed, 10.6 kW (3 ton), 14 SEER, 8.35 HSPF, high velocity ducted system. These two systems operated side-by-side, using separate supply ducts and a common return duct, on a weekly alternating schedule to condition the home that was operated with very consistent, simulated thermal loads. We wanted to know if the high velocity system could provide comparable energy use efficiency to the conventional system. The results of this study showed that it did meet the required loads while doing so with slightly greater efficiency; the average cooling coefficient of performance (COP) was (0.40+/-0.11) higher, and the average heating COP was statistically equal. A new firmware was provided at the end of the heating season which greatly improved the performance of the high velocity system; its average heating COP went from (1.8+/-0.9) to (2.5+/-1.1) at a 95 % confidence level. The new firmware heating COP averaged (1.05+/-0.23) higher than the old firmware over the same outdoor temperatures. Defrost performance is very different for these two systems yet they consumed equivalent energy per HDD; the conventional system uses a timed-initiate, temperature-terminate algorithm with auxiliary electric resistive heating while the high velocity system uses calculated evaporator parameters with a hot-gas bypass before a full reverse cycle defrost with no supplementary resistive heat.
