Download or read book Room Air Stratification Model for Underfloor Air Distribution System written by Qiang Zhang and published by . This book was released on 2001 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Underfloor Air Distribution UFAD Design Guide written by Fred S. Bauman and published by Bibliotheca Press. This book was released on 2003 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide is ideal for HVAC design engineers, architects, building owners, facility managers, equipment manufacturers and installers, utility engineers, researchers, and other users of underfloor air distribution (UFAD) technology. UFAD systems are innovative methods for delivering space conditioning in offices and other commercial buildings. Improved Thermal Comfort, Improved Ventilation Efficiency and Indoor Air Quality, Reduced Energy Use and Reduced Life-Cycle Building Costs -- The guide explains these as some of the advantages that UFAD systems have over traditional overhead air distribution systems. This guide provides assistance in the design of UFAD systems that are energy efficient, intelligently operated, and effective in their performance. It also describes important research results that support current thinking on UFAD design and includes an extensive annotated bibliography for those seeking additional detailed information.
Download or read book Underfloor Air Distribution A Comprehensive Guide to Modern HVAC Systems written by Charles Nehme and published by Charles Nehme. This book was released on with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing demand for energy-efficient, sustainable, and flexible building systems has reshaped how we design and operate modern workspaces. As a crucial component of contemporary HVAC systems, Underfloor Air Distribution (UFAD) technology offers an innovative approach to air delivery that can significantly enhance both occupant comfort and energy efficiency. This book aims to provide a comprehensive guide for engineers, architects, facility managers, and professionals involved in the design, installation, and operation of UFAD systems. Over the past few decades, the evolution of building technologies has prompted a shift away from traditional overhead air distribution systems. UFAD systems, with their ability to deliver conditioned air directly from the floor, are proving to be particularly effective in open-plan offices, data centers, and spaces requiring adaptive layouts. However, as with any system, the success of a UFAD system hinges on a thorough understanding of its design principles, proper installation, and ongoing maintenance. This book was born out of the need for a clear, structured resource that can guide professionals through the complexities of UFAD—from the fundamental science behind air distribution to the nuances of real-world system implementation. Each chapter builds upon the last, starting with an introduction to UFAD and gradually delving into more detailed aspects like airflow dynamics, commissioning, and sustainability. While UFAD offers numerous benefits, such as increased energy efficiency, improved thermal comfort, and design flexibility, these advantages are realized only when the system is designed and maintained with precision. Throughout this book, we will explore not only the technical aspects of UFAD systems but also practical insights and lessons learned from successful projects. I hope that this book serves as a valuable resource for professionals at all levels—whether you are considering UFAD for a new construction project or seeking ways to optimize an existing system. By understanding both the opportunities and challenges that UFAD presents, you can leverage this technology to create more comfortable, energy-efficient, and adaptable environments. Thank you for embarking on this journey into the world of UFAD. I am confident that, together, we can push the boundaries of what is possible in building design and air distribution.
Download or read book Performance Assessment of Commercial Underfloor Air Distribution Buildings written by Yoon Soo Lee and published by . This book was released on 2009 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Time dependent Responses of a Mechanical Displacement Ventilation DV System and an Underfloor Air Distribution UFAD System written by Jong Keun Yu and published by . This book was released on 2010 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: As alternative systems for saving cooling energy compared to conventional overhead (OH) air-conditioning systems, mechanical displacement ventilation (DV) systems and underfloor air distribution (UFAD) systems have been widely adopted for commercial buildings. In these alternative systems, supply air is discharged from low momentum diffusers located at lower positions close to the floor in the DV system, and the supply air of the UFAD system is distributed by an underfloor plenum and discharged from floor diffusers. To predict transient vertical temperature responses when the heat source or the ventilation flow rate vary in time, we introduce transient two-layer stratification models of the DV and UFAD systems, non-dimensionalize them by competing the filling box time (Baines & Turner 1969) and the replenishment time in which all the air in the enclosure is replaced by supply air and validate them by laboratory experiments using a salt-water analogy. In various scenarios of the heat source and the ventilation flow rate, the models show a good agreement with the laboratory experiments. Building energy simulation, which predicts cooling and heating demands of a building, has been used for building design, environment, economics, and occupant comfort. EnergyPlus, which is a building energy simulation tools developed by the U.S. Department of Energy, has integrated capability to predict cooling and heating demands as well as the HVAC (heating, ventilation and air conditioning) energy consumption. To evaluate performance of energy savings of UFAD, we developed prototype office buildings adopting OH and UFAD, and the UCSD-UFAD model was used to estimate realistic cooling and heating demands by simulating the stratified temperature profile in a room. In Californian climates, annual electricity consumption of UFAD is always lower than that of OH by up to 20 %, since UFAD has more opportunities to utilize the economizer ``free cooling" compared to OH. For electricity demand reduction of various Demand Response (DR) activities, increasing room set point temperature is the most effective DR activity and UFAD has higher peak demand reduction compared to OH by approximately 6-10 % when the room set point temperature is higher than 26 Celsius.
Download or read book Air Distribution in Rooms written by H.B. Awbi and published by Elsevier. This book was released on 2000 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt: The air distribution in occupied spaces is a major issue of public concern. It is widely recognized that the quality of air and the nature of airflow can affect the health of occupants and the energy consumed in buildings and transport vehicles. ROOMVENT is the principal international conference in the field of air distribution. It was first initiated in 1987 by SCANVAC, the Scandinavian Federation of Heating, Ventilating and Sanitary Engineering Associations in Denmark, Finland, Iceland, Norway and Sweden. The aim of the Conference is to bring together researchers from universities and research institutes, engineers from industry and government officials and policy makers, with the goal of experiencing the latest techniques for measuring and analyzing indoor air flow, the visualization of indoor air flow patterns, the evaluation of ventilation parameters and the most recent developments in computer simulation techniques of room airflow. It is hoped that the theme of ROOMVENT 2000 "Ventilation for Health and Sustainable Environment" will set the scene for room air distribution research and development for the new millennium.
Download or read book Performance of Underfloor Air Distribution in a Fieldsetting written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Underfloor air distribution (UFAD) is a new method of supplying heated or cooled air throughout a building. Reported advantages of UFAD include energy savings and improved indoor air quality (IAQ). We measured several aspects of the performance of an UFAD system installed in a medium-size office building. The measured air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution. The pollutant removal efficiency for carbon dioxide was 13% higher than expected in a space with well-mixed air, suggesting a 13% reduction in exposures to occupant generated pollutants. The increase in indoor air temperatures with height above the floor was only 1 to 2 C. This amount of thermal stratification could reduce the sensible energy requirements for cooling of outdoor air by approximately 10%. The occupant's level of satisfaction with thermal conditions was well above average and this high satisfaction rating could possibly be due, in all or part, to the use of a UFAD system. The results of this study provide some evidence of moderate energy and IAQ-related benefits of UFAD. Before general conclusions are drawn, the benefits need to be confirmed in other studies.
Download or read book Performance and Optimization of an Underfloor Air Distribution System in an Educational Building in a Hot and Humid Climate written by Vasiliy Khmelenko and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Today there is a proliferation of different HVAC system configurations. Design and performance of each HVAC system are dependent on climate and the intended use of the building. Energy recovery ventilation is becoming more common in new buildings and is one of the more popular retrofit options in hot and humid climates. Currently there is a lack of optimization strategies that involve the underfloor air systems combined with Energy Recovery Ventilation (ERV) especially in hot and humid climate. This thesis examines the performance and optimization of underfloor air distribution systems (UFAD) in hot and humid climates. This thesis also compares the UFAD system performance to a typical overhead air handler unit (AHU) system found in Texas. The performance comparison is done with EnergyPlus modeling software. Separate sets of models are created to examine performance of at different operational parameters. The minimum air flow rates are modeled at 0.1 cfm/ft2, 0.2 cfm/ft2, 0.3 cfm/ft2, 0.4 cfm/ft2 for both UFAD and overhead (OH) systems. The supply air temperatures were modeled at 55°F, 60°F, and 63°F. Outside air strategies include simple economizer, energy recovery ventilation (ERV), as well as a combination of both economizer and ERV. The study found that at low minimum (0.1 cfm/ft2) flow rates an overhead system will slightly outperform a UFAD system (OH 2.6% cheaper to operate than UFAD) while at 0.3 cfm/ft2 a UFAD system is more efficient (UFAD 14.8% cheaper to operate). The outside air strategies have the same energy savings effect on both systems. The UFAD system has a higher peak cooling load and a lower peak heating load compared to the overhead system. This thesis also covers the stratification and supply air temperature measurements within two offices inside the Mitchell Physics building, located on the Texas A&M campus. The stratification measurements showed that on average the stratification was lower than expected for such systems with office 411 having average stratification of 1.8°F and office 423 average stratification of 1.5°F. Temperature measurements at the diffuser level showed some reheat, especially during unoccupied periods such as early mornings, late evenings and weekends, even when the outside temperature was above the interior thermostat set point. System level total supply air flow rate showed little variation with a minimum of 0.47 cfm/ft2 and a maximum of 0.59 cfm/ft2. The analysis of energy recovery wheel operation concluded that the low exhaust air flow of only 0.2 of the outside air is responsible for the low temperature difference observed in the outside air stream through the ERV. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155245
Download or read book Proceedings of the 8th International Symposium on Heating Ventilation and Air Conditioning written by Angui Li and published by Springer Science & Business Media. This book was released on 2013-09-30 with total page 623 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 8th International Symposium on Heating, Ventilation and Air Conditioning is based on the 8th International Symposium of the same name (ISHVAC2013), which took place in Xi’an on October 19-21, 2013. The conference series was initiated at Tsinghua University in 1991 and has since become the premier international HVAC conference initiated in China, playing a significant part in the development of HVAC and indoor environmental research and industry around the world. This international conference provided an exclusive opportunity for policy-makers, designers, researchers, engineers and managers to share their experience. Considering the recent attention on building energy consumption and indoor environments, ISHVAC2013 provided a global platform for discussing recent research on and developments in different aspects of HVAC systems and components, with a focus on building energy consumption, energy efficiency and indoor environments. These categories span a broad range of topics, and the proceedings provide readers with a good general overview of recent advances in different aspects of HVAC systems and related research. As such, they offer a unique resource for further research and a valuable source of information for those interested in the subject. The proceedings are intended for researchers, engineers and graduate students in the fields of Heating, Ventilation and Air Conditioning (HVAC), indoor environments, energy systems, and building information and management. Angui Li works at Xi’an University of Architecture and Technology, Yingxin Zhu works at Tsinghua University and Yuguo Li works at The University of Hong Kong.
Download or read book A Study of the Thermal Comfort and Ventilation Performance of an Underfloor Air Distribution System written by Jae D. Chang and published by . This book was released on 2007 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIR DISTRUBUTION IN ROOMS Ventilation for Health and Sustainable Enviorment Volume II written by Marco Maroni and published by Elsevier. This book was released on with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Underfloor Air Distribution UFAD written by Liangcai Tan and published by . This book was released on 2008 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project covered the laboratory investigation phase of Task 2 where the performance and cost effectiveness of underfloor air distribution and conventional air distribution systems were compared.
Download or read book UFAD O M Guide written by ASHRAE. and published by . This book was released on with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A comprehensive guide on the operations and maintenance of underfloor air distribution systems. Offers practical advice for the builder, technician, and building owner or their representative"--
Download or read book An Examination and Analysis of Residential Applications of Under Floor Air Distribution Systems Using a Realistic Test Environment and Methodology to Assess Thermal Performance for Heating and Cooling Conditions written by Ryan D. Meyer and published by . This book was released on 2011 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under Floor Air Distribution systems hold significant potential for improving residential heating and cooling efficiency and effectiveness. A versatile, realistic residential UFAD system testbed is essential to research establishing the feasibility and commercial potential for these systems. This research work established an operating testbed and a complete testing and analysis methodology for assessing residential UFAD system thermal performance. The testbed supported experiments examining multiple diffuser configurations under both heating and cooling conditions. This research also examined the potential for integrating numerical methods with experimental data from a realistic residential test facility. Analysis of the collected experimental data showed excellent air distribution performance for nearly all diffuser configurations. Experimental data measured minimal temperature stratification and showed UFAD system heating performance equal to cooling performance. This research established Wyoming's first permanent residential UFAD system test environment supporting a broad range of future research.
Download or read book Study of Mixing Under Floor Air Distribution Using Zonal Model based Simulation and Experimental Measurements written by Hong Fang and published by . This book was released on 2014 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major function of HVAC systems is to create comfortable and healthy indoor environment to occupants. Compared to traditional mechanical ventilation such as overhead ventilation and displacement ventilation, mixing u nder f loor a ir d istribution (UFAD) is a more effective ventilation system because it incorporates the advantages of overhead ventilation and displacement ventilation. When predicting the performance of a ventilation system, zonal model is a good method as its complexity and function are between the multi-zone model and CFD model, which are the widely used two numerical simulation methods for indoor environment. Multi-zone model is a so simplified method that it cannot provide environmental details but, as a very detailed calculation tool, CFD requires high computational cost and highly educated simulation users. Zonal model offers some level of detailed environmental information with very limited computational cost. This thesis presents the potential of using zonal model to simulate indoor airflow and temperature distributions for a lab-scale mixing UFAD system. At first, this work has re-derived the numerical algorithms for the zonal model targeting mixing UFAD application by following the direction of an established zonal model - POMA. A computer program from re-derived zonal model thus has been developed, where the numerical algorithm has been disaggregated into two separate components: natural convection and mechanical convection. The re-derived zonal model and the newly developed computer program have been validated using lab experiments under mixing UFAD ventilation. The comparison figures have validated that the re-derived zonal model can accurately predict temperature distributions and reasonably estimate airflows for mixing UFAD ventilation.
Download or read book Design Energy Simulation for Architects written by Kjell Anderson and published by Routledge. This book was released on 2014-01-23 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading architectural firms are now using in-house design simulation to help make more sustainable design decisions. Taking advantage of these new tools requires understanding of what can be done with simulation, how to do it, and how to interpret the results. This software-agnostic book, which is intended for you to use as a professional architect, shows you how to reduce the energy use of all buildings using simulation for shading, daylighting, airflow, and energy modeling. Written by a practicing architect who specializes in design simulation, the book includes 30 case studies of net-zero buildings, as well as of projects with less lofty goals, to demonstrate how energy simulation has helped designers make early decisions. Within each case study, author Kjell Anderson mentions the software used, how the simulation was set up, and how the project team used the simulation to make design decisions. Chapters and case studies are written so that you learn general concepts without being tied to particular software. Each chapter builds on the theory from previous chapters, includes a summary of concept-level hand calculations (if applicable), and gives comprehensive explanations with graphic examples. Additional topics include simulation basics, comfort, climate analysis, a discussion on how simulation is integrated into some firms, and an overview of some popular design simulation software.
