8:00 AM-9:00 AM
Conference Paper Session 1
Advancements in Ground Source Heat Pump Design
HVAC&R Systems and Equipment
Emperors II (Caesars Palace Las Vegas)
Chair:
Rachel Romero, P.E., NREL
Ground source heat pump (GSHP) designs have been used to reduce energy consumption and CO2 emissions throughout the world. This session explores issues that may arise in installation that could limit their effectiveness. The session includes a case study where simulation and observed energy savings differed and the lessons learned. The session also explores the potential to increase the effectiveness of GSHPs by using the built environment already around us. For example, are underground railways in urban environments an untapped heat resource?
1 The Potential for Integration of Ground Energy from Underground Railway Tunnels (LV-17-C001)
Heat networks can be an effective way of supplying low carbon heat to buildings. Current UK systems are largely based on fossil fuel Combined Heat and Power (CHP). Such systems may likely be unacceptable in the long term, if the levels of decarbonization visualized in the UK are to be attained. Heat networks are best suited to areas with high heat demand density such as big cities. This paper demonstrates that Underground Railways (UR) could be an attractive year round heat source and presents numerical investigations into the interactions between these systems.
2 Analysis of Heat Source Water Supply Network Between Two Buildings Utilizing Ground Heat and Exhaust Heat (LV-17-C002)
Ground source heat pump system can reduce energy consumption and CO2 emission of heating, cooling and hot water supply system in buildings. The capacity of ground heat exchanger is subjected to the restriction of the building or site area and this leads frequently to the situation where the amount of heat supply from ground heat source does not balance the heat demand by whole the building. A heat source water supply network was designed and installed between two actual buildings in Japan.
3 Metering Measurement Challenges and Monitoring of a Large Scale Ground Source Heat Pump System (LV-17-C003)
Ground Source Heat Pumps (GSHP) have significant potential to reduce carbon emissions. The performance of heat pumps is highly dependent on their interaction with the ground and specifically the extraction and injection of the heat. A number of literature reviews has shown how the performance of GSHP systems vary in practice when compared to the theoretical aspects. This paper provides detailed investigative work on heat metering installation difficulties and associated errors which affect the long term practical performance of GSHP systems and identifies a range of installation errors.
9:45 AM-10:45 AM
Conference Paper Session 2
Modern Optimization Techniques for Hydronic Systems in Data Centers
Mission Critical Design and Operation
Emperors I (Caesars Palace Las Vegas)
Chair:
Adrian Wallace, Johnson Controls
This session discusses several case studies and applications investigating energy consumption and savings techniques for data centers. While addressing the environmental impact of data centers and how to reduce their carbon footprint, the session considers the life cycle approach to data center operation and further the conversation by considering various types of cooling systems available, their configurations and the layout of the space being served in order to most effectively and efficiently maintain that mission critical space.
1 Energy and Water Environmental Trade-Offs of Data Center Cooling Technologies (LV-17-C004)
Historically, the rising cost of energy has been a huge driver for data center energy efficiency, and the contribution of this consumption to climate change is ever more evident. As the industry begins to look beyond energy consumption, it has become aware that environmental impact derives not just from energy consumption, but also from our use of natural resources. To ensure optimization measures do not cause a burden shift, these interdependent issues should not be considered in isolation. Data centers consume energy to power and cool IT equipment. Current optimization efforts largely focus on the operation of cooling technologies.
2 Thermosyphon Cooler Hybrid System for Water Savings in an Energy-Efficient HPC Data Center: Modeling and Installation (LV-17-C005)
The Thermosyphon Cooler Hybrid System (TCHS) integrates the control of a dry heat rejection device, the Thermosyphon Cooler (TSC), with an open cooling tower. This new heat rejection system embraces a “smart use of water,” using evaporative cooling when it is most advantageous and then saving water and modulating towards increased dry sensible cooling as system operations and ambient weather conditions permit. Johnson Controls partnered with the National Renewable Energy Laboratory (NREL) along with Sandia National Laboratories to deploy the TSC as a test bed at NREL’s high-performance computing (HPC) data center in the first half of 2016.
3 Case Study:Using Simulation Techniques to Optimize Migrations in an Existing Mission Critical Data Center (LV-17-C006)
Citi operates and maintains Data Center space in (3) floors 6, 7 and 8 at the 390 Greenwich street facility. This paper focuses on the 7th and 8th floors. The 8th floor data center comprises approximately 15,000 sq ft (1,500m2) with a power consumption of 500kW, and the 7th floor data center approximately 41,000 sq ft and a power consumption of 1,980kW. The major consumers of energy are the IT equipment, Electrical distribution gear and Cooling equipment. This paper details a study to evaluate the existing conditions of these spaces, and proposals to change to the IT layout, and cooling configuration.
11:00 AM-12:30 PM
Conference Paper Session 3
Health Care Design for IAQ Focusing on Pathogen Minimization
Mission Critical Design and Operation
Emperors II (Caesars Palace Las Vegas)
Chair:
Daniel Pettway, Hobbs & Associates
The spread of contaminants and pathogens in hospitals results in poor IAQ and hospital acquired infections (HAI). This session discusses the airflow distribution in operating rooms and the use of UVGI to reduce bio-film on coil surfaces for improved IAQ and contaminate removal. The session also evaluates a laminar flow newborn incubator's temperature and velocity profiles compared to a conventional incubator. Lastly this session compares international air quality standards and proposes alternate ventilation rates for various healthcare spaces.
1 Restoring Acceptable HVAC Performance with Ultra Violet Germicidal Irradiation Coil Treatment (LV-17-C007)
This paper presents data from theoretical modeling and actual laboratory measurements of the UVC intensities at the surface of typical HVAC coils. To understand how effectively the UVC penetrated the coil’s interstitial spaces, measurements were taken at the coil’s surface, 1”, 2”, 3” and 4” depths respectively. UVC intensities were measured and recorded with a calibrated radiometer. The radiometer was capable of producing results that are traceable to NIST and through NIST to the International System of Units. Modelings demonstrating expected reduction of typical coil biofilms are presented using varying UVC intensities at the varying coil depths.
2 Analysis of Airflow Distribution and Contaminant Flow Path in a Hospital Operating Room (LV-17-C008)
Air is the main carrier of heat, moisture, and other contaminants including the airborne pathogens in the hospital operating rooms. Airflow patterns within the operating rooms and especially in the sterile zone determine the levels of air speeds, temperature, and contaminant concentrations. The spread of pathogens from the sterile zone is directly related to the airflow patterns in the room. This paper with the help of computational fluid dynamics (CFD) analysis demonstrates the effect of return locations and strength of heat sources on the resulting airflow pattern, temperature distribution, and thermal comfort of the occupants within the operating room.
3 Proposed Outdoor Air Ventilation Rationale for Health Care Facilities (LV-17-C009)
Health care facilities have traditionally used two air changes per hour (ACH) for most spaces. This number can be traced back to the architectural literature of the 1870s. It has been carried forward in codes and standards for nearly 140 years and currently is in ASHRAE Standard 170. This paper proposes an alternative rationale for outdoor air ventilation (fresh air ventilation) in health care spaces, based on the contemporary methodologies of ASHRAE Standard 62.1 and other international indoor air quality standards.
4 Comprehensive Design of a Laminar Flow Newborn Incubator (LV-17-C010)
A premature baby is defined as the baby born in the 22th-37th week of the pregnancy. A baby, born before the 28th week of the pregnancy, can live inside of a newborn incubator with a thermoregulation system. Newborn’s death occurs by water and heat loss due to diseases. A decrement in body temperature causes hypothermia and an increment in body temperature causes hyperthermia that result by the death of the neonatal. For the survival of these babies, a suitable and controllable environment has to be provided. In this study, numerical and experimental analyses of a newborn incubator with a laminar flow unit are investigated.
11:00 AM-12:30 PM
Conference Paper Session 4
Improving Energy Exchange in HVAC&R
Fundamentals and Applications
Emperors I (Caesars Palace Las Vegas)
Chair:
Xiufeng Pang, LBNL
Potential applications of heat recovery to increase energy efficiency is a practical and viable approach to energy conservation. This session includes papers describing several methods of using heat recovery for increased energy efficiency. Different system and building types are examined along with theoretical, modeling and case evaluations for effectiveness.
1 Environmental Parameters for Decontamination Room in Sterile Processing Department in U.S. Hospitals (LV-17-C011)
This paper evaluates the indoor environmental conditions of the Decontamination Room in the Sterile Processing Department (SPD) in US Hospitals. Research is scarce on assessing for the indoor conditions in these rooms. This outlines the criteria used for the evaluation process and summarizes the environmental requirements and recommendations related to applicable codes and standards. It provides recommendations for indoor environmental parameters.
2 Sensitivity of Energy and Exergy Performances of Heating and Cooling Systems to Auxiliary Components (LV-17-C012)
Heating and cooling systems in buildings can be divided into three main subsystems: heating/cooling plant, distribution system of the heat transfer medium, and indoor terminal unit. The choice of terminal unit is critical due to its direct effects on thermal indoor environment and system energy use. This paper reports the results of energy and exergy analyses of a single-family house, and an office room, theoretically assuming that they were heated or cooled by an air-based (air heating and cooling) or a water-based system (radiant floor heating and cooling).
3 Heat Recovery from Industrial Flue Gases with Varied Humidity Ratios Using Liquid Desiccant Technology (LV-17-C013)
In 2013, about 66% of the total energy in China is supplied by coal, 18.4% by petroleum and 5.8% by natural gas. The humidity ratio of the exhaust gas differs according to the type of fuels as the fuel with higher hydrogen content will produce more water vapor during combustion. The latent heat occupies a large proportion of the total exhaust heat and will contribute a lot to energy saving if fully utilized. This paper introduces a system used for waste heat recovery from flue gases with the liquid desiccant serving as circulatory mediator.
4 Metropolitan Integrated Cooling and Heating (LV-17-C014)
This project investigates the potential benefits of combining cooling of London underground train tunnels with the transfer of heat to district heating networks. Instead of using air cooled chillers to cool the air in the underground tunnels, it is planned to use water to water heat pumps to transfer the heat to a district heating network. This should significantly reduce the total energy input required for both the heating and cooling of the respective networks. It has been previously estimated that there is at least 25 MW of waste heat available from cooling the London underground system.
5 Women in the Refrigeration Industry (LV-17-C015)
The refrigeration industry plays a major role in today’s global economy, with significant contributions made in food, health, energy and environmental domains which policy makers need to better understand and take into account. The need for engineering and technical staff is currently increasing due to the growing demand for refrigerating capacities, along with the unique skills required of refrigeration-related professions in the field of energy and environment. Women are still significantly and visibly under-represented in the refrigeration industry. This paper demonstrates the current preliminary state-of-the-art of women in the refrigeration field collected from the national refrigeration institutions and associations.
1:30 PM-3:00 PM
Conference Paper Session 5
Designing Energy Efficient Buildings Can Save Money and Provide Better Comfort
Building Operation and Performance
Emperors II (Caesars Palace Las Vegas)
This session addresses issues in energy efficiency in design through building operation, involving conversations ranging from energy conservation relating to older units, insulation or controls. Likewise, specific building types and locations such as hospitality, religious, or green buildings and tropical climates, are discussed for their unique energy demands.
1 Thermal Insulation System for Energy Efficient and Green Buildings (LV-17-C016)
Building construction has gone for tremendous changes during the last decade. With the improvement in quality of life, earnings, living style, the building construction methodology and construction materials have been modified to suit the life style of people. The art of living has changed and human comfort is given a lot of importance. With the increase in electronic gadgets in the houses along with air conditioning system energy consumption becomes enormous. This paper highlights different insulation materials along with application specifications and confirmation to local Green Standards or Energy Codes in India.
2 Experimental Investigation of Potential Energy Savings and Payback Ratio in Renewing Old Split-Type Air Conditioners (LV-17-C017)
Saudi Arabia has been in rapid growth in recent years which resulted in electricity consumption growth. Air-conditioners (A/Cs) are responsible for 50% of the electricity consumption due to hot weather conditions as well as the delay in implementing A/Cs performance standards. One of the challenges is that most of the installed A/Cs in existing buildings are old and have been installed before regulations and standards on A/Cs specifications were enforced in 2013. Renewing old A/Cs with new and efficient ones would reduce electricity consumption, benefiting building owners as well as utility companies.
3 Development of a Hardware-in-the-Loop Framework with Modelica for Energy Efficient Buildings (LV-17-C018)
Buildings consume more than 40% of energy in the U.S. Effectively and efficiently managing and controlling building energy and mechanical systems for a sustainable built environment remains a critical challenge. Studies shows intelligent building controls enable a greater than 20% energy savings in specific buildings, accounting for 2% of national energy consumption. Even small improvements in control system logic can make significant changes in energy savings over the course of a year or longer. How to develop, test and evaluate controller performances is crucial for scalable deployment of these control logics including load controls and distributed control solutions.
4 Energy Saving with Comfort Guarantee in Hospitality Buildings (LV-17-C019)
In a hospitality building, guests’ presence ratio (%) in the room is low due to the varying schedule and needs (business, shopping, sightseeing etc.) of individual guests. So, the energy consumption can be reduced during guests’ absence by turning the HVAC off for the room, but it can cause discomfort to the guest when they come back to the room. So it poses trade-off problems to maintain the comfort for the user and reduces the energy consumption at the same time in a hospitality building. This paper proposes an algorithm to solve the above-mentioned problem.
5 Best Practices and Lessons Learned in Churches: How Energy Use and Efficiency in Religious Facilities Compares to Other Types of Commercial Buildings (LV-17-C020)
Religious facilities throughout the world are unique in their operation compared to other types of commercial buildings. Due to their lower energy intensity, these buildings rarely are the recipients of traditional energy studies or assessments. This paper presents highlights from a long-term energy study of two architecturally-identical churches located in different climates. Data were collected from over 130 sensors over an 18-month time period. This paper discusses how religious facilities differ from other types of commercial buildings in regards to occupancy, lighting, HVAC usage, and comfort.
1:30 PM-3:00 PM
Conference Paper Session 6
Energy Efficient Design for Buildings with an Industrial Focus
Energy Efficient Industrial Buildings
Emperors I (Caesars Palace Las Vegas)
Chair:
David Yashar, NIST
Saving energy in our home or office comes easy to most of us. But what about when designers are faced with saving energy in food processing plants, factories, or even refineries – facilities where health and safety regulations play a crucial role? This session looks at three such cases of applying energy efficiency measures while maintaining a safe workplace environment. It also explores a new approach to thermal comfort studies in the indoor environment.
1 Performance Assessment of Fanger's PMV in a UK Residential Building in Heating Season (LV-17-C021)
Traditionally there are two approaches to thermal comfort studies in the indoor environment. The first approach is to conduct tests in fully controlled climate chambers located in laboratories which help in maintaining desired environmental conditions for the experiments. The alternate/second approach is to place sensors and collect data in a set of homes and offices over a period of time where researchers have virtually no control on the thermal environment. This paper reports on an original approach that combines the advantages of both these methods. In this research thermal comfort studies were conducted in a test house.
2 Integrating Energy Efficiency Performance in Processes for the Dairy Industry (LV-17-C022)
The dairy industry is one of the most energy intensive sectors in food processing; mainly concentration and spray drying are responsible for high energy consumption. One overall objective is to significantly reduce the energy consumption. Savings are expected to reach over 60%. Amongst others the German Federal Ministry for Economic Affairs and Energy Public Relations publish a subsidy for energy efficient and climate friendly production processes. This program is a good opportunity to the dairy sector in Germany and will lead to increased competitiveness. This presentation focuses on spray dryer plants.
3 An Application of Energy Conservation Measures to a Middle-Sized Factory Using Energy Management System (LV-17-C023)
This paper shows positive results for introducing energy conservation measures after analyzing facility data acquired by Energy Management System in an existing middle-sized factory. The factory produces around 400,000 gas meters a year. It achieved 37% CO2 reduction from 2011 to 2014. Since 2011, some simple measures had been implemented such as switch-off of unused lights and air-conditioners for unoccupied areas. To achieve higher energy conservation, reduction of air-conditioning load with no drop in productivity and workplace quality was critical. To design new effective energy conservation measures it was necessary to analyze room condition data and energy usage data.
4 Energy Efficiency in Buildings Inside Oil Refineries (LV-17-C024)
Buildings located inside oil refineries are a typical example of industrial buildings where designers need to balance life safety and energy efficiency. The three most common hazards that such buildings are subject to are blasts, toxic gasses and flammable gasses. The key to achieving energy efficiency without compromising life safety is to understand the hazards imposed on a certain refinery building and the mitigation measures required. This paper describes how a Vapor Cloud Explosion (VCE) differs from regular explosion and how selecting the right blast damper for the over-pressure and impulse of a specific blast will result in energy savings.
8:00 AM-9:30 AM
Conference Paper Session 7
Advances in Building Simulation Tools
Fundamentals and Applications
Emperors II (Caesars Palace Las Vegas)
Chair:
Christopher R. Laughman, Ph.D., Mitsubishi Electric Research Laboratories
Interest in the use of predictive energy modeling tools as guides to support decision making continues to grow. This session discusses in detail advances in calculation methodology, improved procedures for standardizing model input data and the use of templates for rapidly constructing complex models for energy use predictions. In addition, the session proposes innovative solutions to addressing the performance gap between expected and realized energy performance.
1 General-Purpose Building Energy Simulation Program BEST for the Energy-Saving Standards in Japan (LV-17-C025)
In order to promote energy conservation, the building owner shows the understanding of the energy-saving efforts, the designer is committed to energy-saving design of the building, and government has a role to review the precise energy-saving buildings. BEST is a building energy-saving simulation program that’s been developed since 2005, as a suitable software in order to promote energy conservation. It is a life-cycle design software that can be utilized in the design and operation phase as well as corresponding to the energy conservation law. BEST is used as a simulation software that corresponds to Japan's Energy Conservation Law from 2009.
2 Development of Equipment Characteristics Databases of BEST Program (LV-17-C026)
One of the factors for obsoleting a simulation tool is not updating the Equipment Characteristics after the release of the program. For this reason the BEST (Building Energy Simulation Tool) program committee, the section meetings for Equipment Characteristics are held continuously and the BEST program’ Equipment Characteristics is updated frequently. The section meetings are held among the type of equipment, and there are cooperation agreements of Industry Association at the section meetings. The Equipment Characteristics’ databases are made up of two models (statistical model and physical model), and the databases hold three datasets (rated Characteristics, mid Characteristics, dynamic characteristics).
3 Features and Capabilities of Integrated Building Energy Simulation Program Newly Developed in Japan, BEST (LV-17-C027)
BEST (i.e. Building Energy Simulation Tool) is a whole building energy simulation software. Its development was started by a Japanese industry-government-academia joint team in 2005. Since then, BEST has continuously been refined. This paper describes the concept and the features of the latest version of BEST relating to simulation methodology, databases and user interfaces and also presents the simulation results that shows the specific capabilities of BEST. BEST enables integrated simulations of building behavior and control operation of HVAC systems as well as electric and plumbing systems.
4 Simulation Method of HVAC Systems Using Self-Adjusting Templates in the BEST (Building Energy Simulation Tool) (LV-17-C028)
This paper describes simulation methodologies of HVAC systems using self-adjusting template, which are implemented in the BEST program. To achieve extensibility and ease of maintenance, modular structure is introduced. Any appliance is modeled as a module class that implements formatted common functions. One of the new features of the BEST program is “template” structure by which effort for making input data is considerably reduced. Templates are a partial systems implemented, should be prepared in advance connected parts of more than one module.
5 Real Time Data Monitoring to Get Operations on Track (LV-17-C029)
While buildings will always have unique characteristics, there are a number of strategies that can help close the gap between the expected and realized energy performance. This paper presents common issues that arise from the design phase to ongoing operation of buildings. The paper focuses on monitoring-based commissioning using real time data and advanced software analytics to uncover and resolve problems. Real world examples are presented to showcase the challenges faced with complex equipment operation. Examples of technical issues uncovered during commissioning will be provided along with solutions to reduce these issues in the future.
8:00 AM-9:30 AM
Conference Paper Session 8
Designing Hydronic Systems Using Energy and Water Conservation Practices
HVAC&R Systems and Equipment
Emperors I (Caesars Palace Las Vegas)
Chair:
Bill Murphy, University of Kentucky
This session provides three real-world studies: energy efficient heat exchanger design in a natatorium, effect of architectural screens on energy consumption for a cooling tower, and potential water and energy savings associated with reusing ablution water to run mosque air-conditioning systems. Another study explains how recent market influences, advances in centrifugal compressor technology, and new refrigerant choices have coincided to make centrifugal compressors a viable application for air cooled packaged chillers. Also included is a study exploring the ever-changing dynamic of air-cooled versus water-cooled systems, along with the major growth of renewable power generation in grid energy mix.
1 Centrifugal Compressors in Air-Cooled Package Chillers: Coincidence of Market Forces and Technology (LV-17-C030)
The air cooled packaged chiller is a very popular choice for HVAC designers in capacities up to and slightly above 1,900 kW (550 tons). Until recently, the only compressor types commonly available in air cooled packaged chillers across that entire range were of the positive displacement type. By contrast, for nearly 100 years, the efficiency and other inherent advantages of centrifugal compressors have made them a popular compressor choice in water cooled packaged chillers with capacities as low as 350 kW (100 tons). This article explores the history of centrifugal compressors when applied in air cooled chiller systems.
2 A HEAT Pipe Indirect/Direct Evaporative Cooling/Humidification Design for Natatorium IAQ and Energy Savings, Too (LV-17-C031)
Although counter intuitive, using a heat pipe air-to-air heat exchanger in summer for both sensible cooling (Indirect) and adiabatic cooling and humidification (Direct) of the outdoor air in an arid climate can reduce peak refrigeration tonnage while exceeding Standard 62.1 outdoor air ventilation for a Natatorium. Heat recovery in cold ambient conditions allows the system to exceed minimum code outdoor air flow requirements into the Natatorium to dilute and remove Chloramines and maintain a better Indoor Air Quality ( IAQ) in the pool enclosure without additional heating costs. This case study analyzes the Aquatic Center project installed in Dublin, California.
3 Sustainability, Energy and Water: Air-Cooled Versus Water-Cooled Heat Rejection (LV-17-C032)
This conference paper explores the ever-changing dynamic of air-cooled versus water-cooled systems. While water-cooled systems still often reduce the building energy use, there have been dramatic improvements in air-cooled chiller performance. There is increasing concern with fresh water scarcity as we acknowledge the cost and energy consumption required at desalination and water treatment plants. And there’s major growth of renewable power generation in the grid energy mix which affects both the process water use and greenhouse gas emissions. The market’s demand for sustainability, energy efficiency, and water efficiency must be weighed carefully as competing interests continue to evolve over the next decade.
4 Energy Cost of Architectural Screens Around a Cooling Tower (LV-17-C033)
Roof top equipment is often concealed for aesthetics reasons, by a solid or louvered parapet walls aka “Architectural Screens”. This results in inefficient dispersion of exhaust air and reduces the thermal efficiency of the equipment inside the screens. This work estimates excess energy used at an 8000 tons district cooling plants when cooling tower fan operates at higher speeds to compensate for the entrainment and recirculation of exhaust air caused by architectural walls around a cooling tower. Air properties for two locations: 1) inside the walls near the cooling tower and 2) away from it, outside the walls were monitored and analyzed.
5 Reuse of Ablution Water for Mosque Air Conditioning Using Indirect/Direct Evaporative Cooling Technology in Saudi Arabia (LV-17-C034)
There are nearly 60 thousand Mosques spread across the Kingdom of Saudi Arabia, consuming nearly 3 Terawatt-Hour of site electrical energy, 70% of which is due to the use of mostly inefficient HVAC systems. It is estimated that 20 million M3 of expensively treated water used annually for ablution, 50% of which flows directly to the drain without any contamination. This paper evaluates the potential savings in water and energy of reusing ablution water to run mosque Air-Conditioning systems using high efficiency IDEC technology.
8:00 AM-9:30 AM
Conference Paper Session 9
Optimizing Energy and Water Efficiency in Buildings
Water-Energy Nexus
Roman II (Caesars Palace Las Vegas)
Chair:
Jaya Mukhopadhyay, Ph.D., Montana State University
Given that commercial buildings are the largest consumers of water and energy, studying their systems for potential savings is prudent in contemporary designs. This session covers three building systems (commercial dish washing, green walls and cooling towers) and presents research findings for their associated water and energy savings.
1 Performance Based Outcomes: A Case Study on the Stone 34 Project (LV-17-C035)
Stone 34, a 130,000 sq. ft. mixed-use commercial office building, exceeded the aggressive performance standards of Seattle’s Living Building Pilot. The requirements of this program include achieving at least three of the seven petals in the "Living Building Challenge" plus showing a reduction in annual energy usage by 75% when compared to CBECS data, a reduction in potable water usage by 75% and re-use of at least 50% of storm water that hits the site. The Living Building Pilot requires validated performance after 12 continuous months of operation, and both the design team and ownership team faced financial penalties if the building failed to meet the program targets. This paper will explain the "bookend approach" that the design and ownership team used to ensure that the occupied building met the performance requirements.
2 Results from 20 Field Monitoring Projects on Rack and Flight Conveyor Dishwashers in Commercial Kitchens (LV-17-C036)
This research project examines the complexity of conveyor dishwashers, benchmarking water and energy use of old and new dishwashers operating in facilities and identifying strategies to sustain the savings potential of high-efficiency machines. The catalyst for this study was receiving funding from Metropolitan Water District’s Innovative Conservation Grant Program and co-funding from Pacific Gas and Electric Company. These machines are the most water and energy intensive appliances in commercial kitchens with older dishwashers using two to three times their anticipated hot water use when factoring in the manufacturer’s specifications of rinse flow rate and tank volume.
3.00 The Effects of the Green Walls on Building Energy Use and Rainwater Management (LV-17-C038)
Buildings consume 25% of global water and are responsible for 40% of the total world annual energy consumption. Buildings account for 72% end-use electricity in the U.S. with the largest portion spent for cooling and heating of buildings. The key issues for the future of building industry are related to saving of water and energy consumption, and delivering environmental benefits. The objective of this study is to quantify cooling/heating energy saving and rainwater saving due to vertical gardening in buildings by using controlled experiments and building energy modeling.
9:45 AM-10:45 AM
Conference Paper Session 10
Climate and Its Effect on HVAC System Performance
Effects of Climate Change on HVAC&R
Emperors I (Caesars Palace Las Vegas)
Chair:
Jessica Mangler, P.E., Affiliated Engineers, Inc.
This session identifies the need to design an HVAC system around a variable climate. The first study focuses on the transient thermal comfort and sensation reported by subjects over a 20-minute time frame. The second study investigates the effect climate variability would have on Salt Lake County’s future energy demand and air quality impacts, and identifies potential changes communities can incorporate to lower energy demand and improve air quality. The final study explores the interrelationship between climate, enclosure, and micro cogeneration heat to power ratio with the goal of developing and designing enclosure and micro cogeneration systems that are more adaptive to climate changes.
1 Energy Demands for Commercial Buildings with Climate Variability and Associated Air Quality Impacts (LV-17-C039)
The impacts of a changing climate are wide-ranging in both impact and scope. This presentation focuses on the effect climate variability would have on Salt Lake County’s energy demand and air quality impacts. Salt Lake County, UT is a Zone 5, Subtype B climate encompassing the state capital, Salt Lake City, and the University of Utah (UU). Energy demand scenarios derived using climate predictions for 2040-50 are presented at three scales: individual building, central business district, and county level. The Wasatch Front Regional Council’s regional transportation and land use projections for 2040 were used as the backbone of our urbanization growth predictions.
2 Measured Thermal Comfort and Sensation in Highly Transient Environments (LV-17-C040)
Human thermal sensation and comfort are important topics in the design and operation of occupied spaces. Steady state thermal sensation and comfort has been widely studied and has robust predictive models available for designers but responses to transient conditions have received much less attention. The current study reports on the transient thermal comfort and sensation reported by subjects while playing a video game. Chamber temperatures ranged from 25°C starting temperature to 40°C and then back to 25°C in a symmetrical profile design. The rise and fall occurred over a 20 minute time frame.
3 Predicting Micro Cogeneration and Envelope Performance in Future Climates (LV-17-C041)
Micro cogeneration and micro trigeneration technologies have the potential to reduce domestic energy consumption and create more resilient buildings. In this work, variations in residential heat to power ratio due to climate change are assessed in the Northeastern climate of the United States. Simulations of high R-value walls are compared to older wall constructions in current and future climate conditions. Impacts on current micro cogeneration design are discussed. The study explores the interrelationship between climate, enclosure and micro cogeneration heat to power ratio with the goal of developing and designing enclosure and micro cogeneration systems that are more adaptive to climate changes.
9:45 AM-10:45 AM
Conference Paper Session 11
Impact of VOCs and Organics on Ventilation System Design
Commercial and Industrial IAQ
Augustus V/VI (Caesars Palace Las Vegas)
Chair:
Hyojin Kim, Ph.D., The Catholic University of America
Volatile organic compounds (VOCs) can have a serious impact on the IAQ within occupied spaces. This session addresses the use of oxidation as a means of VOC control and removal, and what impact such devices could have on the building ventilation system. One paper also addresses the potential of building occupants as a source of VOCs within the space they occupy.
1 Can Using Active UV-C Technology Reduce the Amount of Bacteria and/or Fungus in the Air and Improve Indoor Air Quality? (LV-17-C042)
UV-C technology has been used as a disinfection method for decades in the healthcare industry. The UV-C wavelength of 253.7 nanometers has been proven to be effective at eliminating or neutralizing dangerous pathogens like C. difficile, Methicillin resistant Staphylococcus aureus and more. The current technologies focus on cleaning surfaces to reduce healthcare associated infections. Three studies were conducted at an acute care hospital, a children’s hospital and a long term acute care facility to determine if reducing the number of colony forming units of bacteria and/or fungus in the air would improve indoor air quality.
2.00 Effects of Air Flow Rates on VOC Removal Performances of Oxidation-Based Air Cleaning Technologies (LV-17-C044)
Volatile organic compounds (VOCs) are a major gaseous contaminant group affecting indoor air quality. Various technologies have been applied for the removal of VOCs. There are conventional systems based on adsorption process, i.e., activated carbon and/or potassium permanganate alumina pellets in trays or deep beds, particulate filters incorporating very thin beds of activated carbon or alumina pellets, and carbon cloth. The objective of this study is to investigate the effects of air flow rates on the performances of oxidation-based air cleaning technologies including UV with photocatalysts, plasma and ozone generators.
11:00 AM-12:00 PM
Conference Paper Session 12
IAQ in the Airline Industry
Commercial and Industrial IAQ
Emperors I (Caesars Palace Las Vegas)
Chair:
Luke Leung, P.E., Skidmore Owings & Merrill
For both passengers and crew members, the quality of air that is circulated within commercial airliners is of particular concern. ASHRAE Standard 161, Air Quality Within Commercial Aircraft, deals with this issue, amongst many others. This session presents papers addressing the difficulties in measuring contaminants in the air in aircraft cabins, and what contaminants need to be measured. One paper also explores the exposure of airline personnel to contaminants both in the air and on the ground.
1 Measurement and Exposure of Airline Staff to Tri-Cresyl Phosphates from Engine Oil (LV-17-C045)
To prevent corrosion, tri-cresyl-phosphate (TCP) is added to aircraft engine oil. TCP occurs in a mixture of ten different isomers. The ortho isomers of TCP are known to be the most neurotoxic, however at present it is unknown in what concentration the ortho and the other isomers occur in cabin air, due to leakage in the air conditioning system, and in engine exhaust fumes. Various professions of airline staff may be exposed to concentrations of TCP. This research describes the assessment of the exposure through measurements inside the cockpit during flight, spot measurements on the ramp and personal measurements of ground mechanics.
2 The Nature of Particulates in Aircraft Bleed Air Resulting from Oil Contamination (LV-17-C046)
ASHRAE Standard 161, Air Quality within Commercial Aircraft, includes a requirement for bleed air sensors to detect contamination from lubricating oil. One potential approach to meeting this requirement is through particle detection. A four-part experimental program was conducted to develop a detailed characterization of particles that result when bleed air is contaminated with lubricating oil. This research shows that development of sensors for detecting oil contamination in aircraft bleed air should focus on ultrafine particle detection and sensing of low contamination levels may require sensitivity to extreme ultrafine particles 10 nanometers and smaller.
3 Experimental Determination of the Characteristics of Lubricating Oil Contamination in Bleed Air (LV-17-C047)
The outside air used to pressurize and ventilate the cabin during flight is supplied by bleed air from the propulsion engine compressors on most airliners. The potential for this air to be contaminated by lubricating oil from leaking engine seals and other sources is believed to be rare. ASHRAE Standard 161, Air Quality within Commercial Aircraft, addresses this issue and includes a requirement for bleed air oil contamination sensing. This standard does not address the technology to be used for this sensing nor does it provide guidance about the physical characteristics of the contaminants as they appear in the bleed air.
11:00 AM-12:00 PM
Conference Paper Session 13
Solar Effectiveness from Roofs to Cooling Panels
HVAC&R Systems and Equipment
Roman I (Caesars Palace Las Vegas)
Chair:
Ratnesh Tiwari, Ph.D., University of Maryland
This session examines performance aspects of three rather different radiation sensitive components/systems used on building envelopes. The first presentation looks at energy saving/thermal comfort trade-offs when different control strategies are used for a system that couples nocturnal radiative cooling panels with phase change ceiling panels in Denmark. The second compares the performance of transparent and opaque building integrated photoVoltaic/thermal collectors in two different locations in Canada. The last paper presents comprehensive measurements of roof solar reflectivity made on 30 different buildings in each of three different cities around the U.S. to get a better understanding of the field performance of high solar reflectivity roofing materials.
1 Field Measurements of Solar Reflectivity for In-Service Single Ply Roof Membranes (LV-17-C048)
High solar reflectivity roof membranes have been a focal point of energy saving efforts in building design. These efforts have been codified in the International Code Council (ICC) International Energy Conservation Code (IECC) and the American Society of Heating and Air-Conditioning Engineers (ASHAE) Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings. In both of these texts prescriptive aged and or initial roof membrane solar reflectivity is specified. This paper reports the numerical findings of this study, examines causation for the differential levels solar reflectivity values discovered and proposes guidelines for roof membrane solar reflectivity used for design and modeling.
2 Parametric Analysis of the Control System of Solar Panels for Nocturnal Radiative Cooling Coupled with PCM Ceiling Panels (LV-17-C049)
As HVAC systems advance to meet the energy savings goals, their control system becomes increasingly complicated. In order to optimize the operation of a control system, the ideal combination of its parameters need to be realized, aiming at providing an acceptable indoor environment as defined by the standards and at the same time reducing the energy use as much as possible. In this simulation study, the coupling of solar panels with Phase Change Material (PCM) ceiling panels for cooling an office room was examined during the cooling season of Copenhagen (Denmark) by means of dynamic simulations.
3 Comparative Performance Evaluation of Transparent and Opaque BIPV/T Collectors: Roof and Façade Integration (LV-17-C050)
Building integrated photovoltaic/thermal (BIPV/T) system provides sustainable solution in design structure as part of the building envelop. A mathematical model was developed for transparent and opaque BIPV/T collector, (TBIPV/T) and (BIPV/T). Both models were implemented in TRNSYS to conduct comparative study. A single zone house was modeled in TRNSYS to conduct a case study to evaluate the performance of each collectors. Comparative studies were performed between both systems, each integrated into the façade and roof of the house for two locations in Canada.
8:00 AM-9:30 AM
Conference Paper Session 14
Optimizing Energy and Ventilation in Residential Applications
HVAC&R Systems and Equipment
Emperors II (Caesars Palace Las Vegas)
Chair:
Frank Shadpour, P.E., SC Engineers, Inc.
This session examines multiple issues related to residential energy efficiency using laboratory results and modeling studies. Air conditioners are typically evaluated using SEER ratings based on performance measurements made across a very limited range of conditions. Measurements made across a much wider range of conditions are presented to help understand how variable capacity systems perform. Another paper discusses the impact of different mechanical ventilation systems used in multi-family buildings on building aesthetics, capital cost, annual energy cost, systems and equipment maintenance, and green construction rating impact. A method using singular value decomposition is introduced to reduce the computation time needed to carry out comprehensive energy optimization studies for residential buildings is introduced and used to perform case studies on a building in six different U.S. locations. Another study looks at the impact of various retrofits and air conditioner upgrades in Saudi Arabia. The final presentation finds differences of as much as +/- 50% in the annual electricity and gas use for the same house calculated by four widely used energy modeling programs and explores reasons for these differences.
1 Building Impacts of Code Compliant Ventilation in Multi-Family Dwellings (LV-17-C051)
Recently the majority of multi-family residential buildings have satisfied the ventilation requirements of the dwelling units via natural ventilation and have not provided an additional means of mechanical ventilation. Changes to ASHRAE Standard 62.1 and the adoption of those changes into local codes require multi-family dwelling units to be mechanically ventilated. This paper evaluates systems and equipment available to meet the code mandated mechanical ventilation requirements and discusses the impacts of the selection on the building. Areas of impact evaluated are building aesthetics, capital cost, annual energy cost, utility billing structure, building space requirements, systems and equipment maintenance and green construction rating impact.
2 Life Cycle Cost Optimization of Residential Buildings (LV-17-C052)
The optimization of energy efficient housing is a highly complex problem involving hundreds of parameters due to the many options that exist at the time that a building is being designed. To perform the optimization in an acceptable time frame, singular value decomposition is used to reduce the number of design variables by identifying those that contribute most strongly to the optimization problem. A case study of residential buildings in six separate locations across the U.S. is performed and the results are discussed.
3 Investigation of Potential Energy Savings in Retrofitting a Residential Building at Riyadh's Weather Conditions (LV-17-C053)
Recent official statistics have shown that Saudi Arabia electricity consumption growth rate at 7%. Buildings primary energy consumption and electricity consumption are 23% and 80%, respectively. This trend of high energy consumption is expected to rise in the upcoming few years. According to governmental statistics, 70% of the buildings in Saudi are not insulated. Furthermore, most of the air-conditioners in existing buildings were installed before enforcing minimum performance standards on air-conditioners. In this paper, an uninsulated existing residential building model was developed and validated against utility data.
4 Real-World Assessment of Three Residential Variable Capacity Air Conditioners of Varying SEER (LV-17-C054)
Variable capacity technology is a core feature in high efficiency air conditioners available in the residential, ducted market. Residential variable capacity air conditioners are available in a range of Seasonal Energy Efficiency Ratios (SEER), exceeding the federal minimum levels. Energy efficiency program implementers seek to understand the efficiency impact of variable capacity systems for their climates and applications. Program implementers seek guidance on structuring their programs based on available industry ratings. This report examines the performance of three variable capacity systems of varying SEER over a range of real-world operating conditions, away from the current standard testing conditions for SEER.
5 Comparison of Building Energy Simulation Models for Residential Homes (LV-17-C055)
Annual energy consumption of a 1200 square foot residential home was modeled using four energy modeling programs: CBECC-Res, BEopt, EnergyPro, and REM/Rate. A baseline house was developed that met California Title 24 Standards, and both slab and crawlspace foundations were considered. The baseline house was additionally modified to have non-compliant (lower-efficiency) inputs, as well as advanced-efficiency inputs, for parameters including insulation, window properties, HVAC system efficiencies and air infiltration. For given set of inputs, the four models produced significant variations in calculated annual electricity and natural gas consumption with differences as high as +/- 50%.
8:00 AM-9:30 AM
Conference Paper Session 15
Ventilation Systems and Their Impact on IAQ and Energy
Commercial and Industrial IAQ
Emperors I (Caesars Palace Las Vegas)
Chair:
Van Baxter, ORNL
HVAC engineers often face conflicting system design goals of maximizing IAQ while minimizing energy usage. This session addresses this complex topic by presenting several different approaches for ‘walking the line’. New information on the measured performance of flexible duct systems is shared, and both clever design and novel control strategies for both active and passive ventilation systems are discussed.
1 Whole-Building Fault Detection: A Scalable Approach Using Spectral Methods (LV-17-C056)
In this work, a novel approach for the automated fault detection and diagnostics (AFDD) of building HVAC operation is introduced utilizing properties of the Koopman operator to extend the capabilities of rules-based FDD approaches. The Koopman operator is an infinite-dimensional, linear operator that captures nonlinear, finite dimensional dynamics. These mathematical aspects translate into algorithms which can effectively evaluate the magnitude and coincidence of data. Using properties of the operator, building management system (BMS) trend data can be decomposed into components which allow the capture of device-to-device interactions as well as device behavior at varying time-scales.
2 Indoor Air Quality of Naturally Ventilated Buildings in a Roadside Environment (LV-17-C057)
Natural ventilation is one of the most important green building features. Although the intention is often to reduce energy consumption, natural ventilation strategies may deteriorate indoor air quality (IAQ) when in close proximity to major roadways. This study employs a CFD-based air quality model to quantify the impact of traffic-related air pollution on the IAQ of a naturally ventilated building in a near-road environment. Our study found that the building envelope restricts dispersion and dilution of particulate matter (PM).
3 Ductless Car Park Ventilation: Global Trends and Design Practices (LV-17-C058)
As cars are parked within an underground parking structure, CO and other exhaust fumes are emitted into the atmosphere. There is a need for an efficient ventilation system that can remove these toxins, circulate fresh air into the garage, and assist fire fighters in the case of a fire emergency. There are two options for this task: ducted or ductless ventilation. Ducted ventilation is heavily used in the US and other global markets. While this has been the standard for many years, innovations in the field of ventilation have shifted the conventional ventilation system towards ductless designs.
4 Lessons Learned of Applying Indoor Air Quality Procedure in Commercial Buildings (LV-17-C059)
ASHRAE Standard 62.1-2013 provides two alternative procedures for selecting the minimum ventilation rate for commercial buildings: the prescriptive Ventilation Rate Procedure (VRP); and the rarely used performance-based Indoor Air Quality Procedure (IAQP). The IAQP allows lower ventilation rates than the VRP and, at a minimum, maintains the same indoor air quality, providing additional contaminant reduction strategies are applied. This paper provides examples, benefits and lessons learned from applying IAQP in various commercial buildings located in a variety of climates.
5 Experimental Measurement of the Hydrodynamics and Thermal Behavior of Airflow in a "Flex-Duct" Air Distribution System (LV-17-C060)
Flexible duct air distribution systems are used in a large percentage of residential and small commercial buildings in the United States. Very little empirical or predictive data is available to help provide the HVAC design engineers with reliable information. The aim of this research is to measure experimentally using the guidelines of ANSI/ASHRAE Standard 120-2008 the friction loss of the air flow inside a realistic layout out flexible duct used for residential/small commercial buildings.
11:15 AM-12:45 PM
Conference Paper Session 16
Building Operation and Performance with Sustainability in Mind
Building Operation and Performance
Emperors II (Caesars Palace Las Vegas)
Chair:
Wade Conlan, P.E., exp US Services Inc
Much research has been done to investigate the overall performance of buildings that were designed for sustainability. This session covers the expectations of design versus the reality of their implementation as well as research on the effectiveness of sensors and building envelopes. One presentation also covers the relationship between renewable resources and the utility grid. A varied array of sustainable building design issues will be covered.
1 The Social Dynamics of a Project (LV-17-C061)
The purpose of this article is to first define traditional social relations of a facility project, from design to demo, and to then reflect how those existing affairs have been affected by this new member to the built association. By focusing on the human relationship to the built environment, the author hopes to promote better project communications; once again from design to demo, among all stake-holders. In order to truly support Green Agendas, as an industry we need to promote and support the relationship between engineering system parameters and those who are ultimately challenged with maintaining those parameters.
2 A Comparison of Stochastic and Deterministic Optimization Algorithms on the Virtual In-Situ Sensor Calibration in Building Systems (LV-17-C062)
A virtual in-situ sensor calibration method has been recently studied in order to solve the practical problems of sensor calibration in building energy systems: (1) time and monetary cost; (2) disruption to a normal operation; (3) difficulty in accessing various embedded sensors in equipment; and (4) large quantity of sensors. The proposed in-situ calibration method is able to approximate the measure and establish benchmark values for a calibration statistically or by using system models, without removing the working sensor or adding reference sensors as in a conventional calibration.
3 Risk of Condensation Analysis of Common Concrete Balcony Configurations (LV-17-C063)
Condensation control of thermal bridges has always been a major concern of designers. In building envelope details, highly heat conductive materials and poor thermal insulations create thermal bridging. Condensation occurs when indoor air hits the cold surface of thermal bridging area which is below dewpoint temperature. Condensation could lead to surface staining, mold growth and deterioration of sensitive materials. The goal of this paper is to develop a catalogue and guidelines that allow designers to verify the condensation resistance of selected balconies in different climate zones, and meet ASHRAE and LEED standards and local codes.
4 Duck – The Volcano is Coming! (LV-17-C064)
A paradigm shift is coming in how buildings interact with the utility grid. Dramatic drops in the price of PV panels has spurred the rise of the “prosumer” (Producer and Consumer): buildings that necessitate a two-way grid interaction. This, plus a renewed focus on energy efficiency, is driving the mainstream adoption of Net Zero Energy (NZE) buildings – a good thing, certainly. However, some important details remain unresolved. As more of these buildings of the future come online it is increasingly critical to make sure that the buildings are good grid citizens and are solving more problems than they create.
5 Infrared Thermography For Building Envelope Analysis (LV-17-C065)
Infrared thermography is a nondestructive technology that can help identify building envelope issues such as wet areas and lack of or inadequate insulation in building envelopes invisible to the human eye. When conducted at the right time of night infrared (IR) inspections can determine which materials are wet or in contact with wet materials and which are dry. This is possible because water has a high specific heat, which means that it stores heat well and cools down more slowly than common roofing materials.
8:00 AM-9:30 AM
Conference Paper Session 17
Building Cooling and Heating System Design
HVAC&R Systems and Equipment
Emperors II (Caesars Palace Las Vegas)
Chair:
David Shipley, P.Eng., ICF Marbek
There are many factors to be considered when determining which is the best HVAC system for any given application. The papers in this session discuss a number of those factors ranging from hydronic heating emitters, to thermally activated building systems, to variable refrigerant flows, to energy recovery.
2 Full and Part Load Performance Evaluation of Variable Refrigerant Flow System Using an Occupancy Simulated Research Building (LV-17-C067)
VRF systems are touted for their superior part-load performance compared to conventional HVAC systems. This study compares both the full and part-load performance of a VRF system with a conventional RTU VAV (rooftop variable air volume) system in a multi-zone office building with emulated occupancy. During the study period starting July 2015 through February 2016, each system was operated alternately under each of the three load conditions for 2-3 days, and the system parameters, indoor and outdoor conditions, loads, and energy use were monitored. The performance of the two systems is compared in terms of weather-normalized HVAC energy consumption.
3 Development of Water-Based Hybrid VRF System for Buildings (LV-17-C068)
Water-based air conditioning system has attracted increasing attention because of their smaller charge amount of refrigerant which is supposed to cause global warming. It is widely used for such as chiller, and there are more requirements for higher efficiency and improvements in workability in building use. This paper discusses the outline of HVRF and explains the refrigerant and water flow. HVRF enables free selection of a cooling mode or a heating mode in each indoor unit. It also discusses the coupled simulation of refrigerant circuit and water circuit.
4 Influence of Acoustic Ceiling Units on the Cooling Performance of Thermally Activated Building Systems (LV-17-C069)
Europe, with a building stock responsible for about 40% of the total energy use, needs to reduce the primary energy consumption in buildings in order to meet the 2020 energy targets of the European Union. High temperature cooling and low temperature heating systems, and as an example, Thermally Activated Building Systems (TABS), have proven to be an energy-efficient solution to provide buildings with an optimal indoor thermal environment. This study focuses on quantifying the impact of two types of free hanging ceiling absorbers (horizontal and vertical), on the cooling performance of the TABS and the implications this has on the occupants´ thermal comfort.
5 Modeling and Simulation ofMembrane-Based Dehumidificationand Energy Recovery Process
This paper presents a first-order physics based model which reasonably accounts for the fundamental heat and mass transfer of vapor from humid air feed side to permeate side. This model comprises two membrane mass transfer submodels (i.e. microstructure model and performance map model); moreover, we adopt a segment-by-segment methodology for discretizing heat and mass transfer governing equations. The reported model is capable of simulating both dehumidifiers and energy recovery ventilators with cross-flow, counter-flow and parallel-flow. The model has been validated with measurements of a working device.
9:45 AM-10:45 AM
Conference Paper Session 18
Modeling for Smoke Management Systems
Fundamentals and Applications
Emperors I (Caesars Palace Las Vegas)
Chair:
Paul Turnbull, Siemens Building Technologies, Inc.
Technical Committee: 05.06 Control of Fire and Smoke
All three conference papers in this session focus on verifying modeling information with hands-on experimentation to validate the modeled results. In the first paper, differential pressures from shaft to building were measured in 15 different buildings. Comparing the experimental results to the modeled results, found that in most cases, hand-calculations underestimate differential pressures. In the second paper, experimentation with smoke movement through a high-rise shaft was undertaken and found that previous modeling methods did not match the experimentation results; so a new and improved method was proposed. In the third paper, a building fire was simulated and data on smoke movement in the shaft was captured. When compared to available modeling software, the experimental results were significantly different. More information about this research and their interesting results are up next.
1 Modeling of Stack Effect in High-Rise Buildings Under Winter Conditions: Evaluating the Validity of Field Observations (LV-17-C071)
To characterize the magnitude of stack effect in existing buildings, differential pressures measurements were taken in fifteen high-rise buildings during the winter of 2013. Four observations were made: (1) unless conservative leakage values are used, typical hand calculations may under-predict the shaft-to-building differential pressures, (2) introduction of cold air into pressurized stairwells cooled the stair, but temperatures remained significantly higher than ambient (3) introduction of cold air into pressurized stairwells caused significant pressure and increased door opening forces required at the bottom of the stairs, (4) pressurization of the stairwells increased pressure and stack effect flows via the elevator shafts.
2 Scale Modeling of Smoke Spread in High-Rise Shafts during Fires (LV-17-C072)
Driven by stack effect, smoke often spreads across a building through shafts, which becomes a major challenge for high-rise fire protections. It is therefore important to conduct research on the smoke movement inside high-rise shafts, for which scale modeling based on experiments in sub-scale models of full-size buildings is an important technique. In this paper, a new scale modeling method is developed based on a group of new dimensionless numbers based on the conservations of both heat transfer and mechanical energy for mechanical and natural venting systems of high-rise shafts.
3 Comparison of COSMO Smoke Management Software and Experimental Measurements of Smoke Properties During a Structural Fire (LV-17-C073)
A group of small-scale test sections consisting of acrylic and gypsum models with a single vertical shaft was used to simulate building fires. A propane burner on the first floor provided high-temperature gases that entered the shaft and moved to the upper floors via stack-effect forces under natural ventilation as well as mechanical exhausting conditions. Vertical variations of the pressure and temperature distribution were measured in the shaft. The locations of the Neutral Pressure Plane were determined based on pressure differences measured with different combinations of smoke mass flow rates and size of openings in the shaft.
9:45 AM-10:45 AM
Conference Paper Session 19
Modern Heat Pump Applications
HVAC&R Systems and Equipment
Augustus III/IV (Caesars Palace Las Vegas)
Chair:
Yunho Hwang, Ph.D., University of Maryland
This session explores new research on residential style heat pumps and their increased efficiency and performance. The first presentation discusses the research of multi-family houses supplied with water source heat pumps tied to a buried storage tank, which reduces compressor electricity and increases COP. The second presentation explores the increased efficiencies of heat pump units when a coating is applied to the coils to minimize defrost. The last presentation discusses recent studies from a gas heat pump’s single-effect absorption cycle and its opportunities of energy savings.
1 Feasibility of Combined Water-Source Heat Pump with Thermal Energy Storage in Multi-Family Dwellings (LV-17-C074)
Residential and commercial buildings play a significant role in the energy consumption sector. Buildings account for approximately more than 30 percent of total energy consumption which proves that energy management in buildings should be prioritized. One of the energy-efficient and cost-effective solutions in energy management is utilizing thermal energy storage. The main benefit of Thermal Energy Storage (TES) is to overcome mismatch between energy generation and energy use. This research is based on the concept of supplying multi-family houses space heating and cooling demands by implementing water-source heat pump which is connected into a buried sensible seasonal storage tank.
2 The Application of Icephobic Coatings to Air-Source Heat Pumps (LV-17-C075)
Eliminating or minimizing the defrost penalty of air source heat pumps will increase their energy efficiency and their market penetration. Preliminary research suggests that coating the outdoor coil of a heat pump with an icephobic coating will lead to reduced (or delayed) frost accumulation and defrosting requirements. Additionally, the coatings may allow faster shedding of ice and shorten the defrost duration. Prior research in nanotechnology has shown that a normal layer of polymer with particles for surface texture approximately 10 to 20 microns thick impacted the heat transfer characteristics of a metal substrate.
3 Development of a Low-Cost Gas Absorption Heat Pump (LV-17-C076)
Most U.S. homes are heated by natural gas, particularly in the Midwest and Northeast. Over 80% are heated by warm-air furnaces which range in efficiency from 80% to 98% AFUE. Recently, higher efficiency “condensing” models have saturated the market, particularly in Northern states, and shifting federal standards will further drive adoption of “condensing efficiency” heating equipment. Looking ahead, an emerging class of gas-fired heat pumps could continue this drive towards high-efficiency gas heating. The authors review findings from a recent development and demonstration of a residential-scale gas heat pump (GHP) for space heating, including results from laboratory and field evaluations.
9:45 AM-10:45 AM
Conference Paper Session 20
Ventilation System Modeling for Improved IAQ
Mission Critical Design and Operation
Emperors II (Caesars Palace Las Vegas)
Chair:
Geoffrey C. Bares, P.E., CB&I
Modeling can provide both designers and building owners/operators with multiple choices in determining how best to meet their energy and IAQ goals for any given type of building. This session provides examples of how modeling can be used to provide alternative HVAC design choices, as well as the level of accuracy required by the modeling to allow for reasonable choices to be made.
1 Air Dehumidification Using Desiccant Coated Oblique Fin Plate Frame Structure (LV-17-C077)
Some researchers have come up with energy-efficient air-conditioning solutions involving the use of desiccants, which largely incorporate the use of low grade waste heat or solar energy rather than electricity. However, issues such as bulkiness of the systems, high initial cost and long pay-back periods, difficulty with retrofitting, non-availability or inconsistent availability of heat sources make such solutions’ market penetration rather challenging. This paper proposes a desiccant (silica gel) coated oblique fin plate-frame structure that can be retrofitted into existing air-ducts. This study suggests the use of oblique fin plate-frame structure to be a plausible alternative to conventional desiccant based air-conditioning solutions.
2 Zero-Equation Turbulence Models for Large Electrical and Electronics Enclosure Applications (LV-17-C078)
Zero-equation turbulence models offer improved speed and, potentially, robustness at the expense of solution accuracy relative to the k-ε and other two-equation models typically employed in CFD simulations. For applications – particularly, initial design – in which absolute accuracy is a lower priority, a zero-equation model is appropriate. We assess several zero-equation models for the thermal modeling of large electronics enclosures (e.g., shipping container size). Comparisons are made between the zero-equation models and benchmark 2D and 3D reference scenarios. Researchers recommend a specific zero-equation model for our target applications and discuss its performance relative to the k-ε model.
3 Numerical Evaluation of Thermal and Ventilation Performance of Passive Chilled Beams (LV-17-C079)
Chilled beam systems provide sensible cooling in the occupied space using chilled water flowing through modular beams mounted to a ceiling. Such systems achieve greater energy efficiency than all-air system due to larger thermal energy of the chilled water than air, and thus are well-suited for spaces with relatively large sensible cooling load. This paper presents a numerically based study focusing on the performance of combined passive chilled beam (PB) systems. Using computational fluid dynamics (CFD) simulation, the amount of sensible cooling by PB and its impacts on ventilation effectiveness and occupant comfort in a typical office room are investigated.
11:00 AM-12:30 PM
Conference Paper Session 21
Optimizing Efficiency in Fin Heat Exchangers
Fundamentals and Applications
Emperors I (Caesars Palace Las Vegas)
Chair:
Steven Eckels, Ph.D., Kansas State University Institute for Environmental Research
Heat transfer efficiency through modern fin heat exchanger design and fenestration is described in this session. Increasing fin efficiency and reducing heat load through fenestration design are highlighted. New research in calculations are revealed and detailed modeling approaches to fin design are also highlighted.
1 Revised Indoor-Side Convection Coefficients for Complex Fenestration Systems with Roller Blinds (LV-17-C080)
ASHRAE research project RP-1311 concluded with the creation of simulation models, the ASHWAT models, for complex fenestration systems (CFS) – glazing systems with attachments such as shades and insect screens. In these models, radiant flux – solar beam/diffuse or longwave –is on a layer-to-layer basis. ASHWAT also takes into account the convective heat transfer between the CFS layers. Methods to obtain convection coefficients for glazing cavities are well established, even for a cavity that includes a venetian blind. In this paper, a new numerical technique is applied to generate new convection coefficients for complex fenestration systems.
2 Comparative Study of Optimized Small Diameter Tube-Fin Heat Exchangers vs. Traditional, Larger Diameter Tube-Fin Heat Exchanger Designs (LV-17-C081)
Recent work has been conducted to characterize the air-side heat transfer and pressure drop performance of heat exchangers with slit and louver fins and tube outer diameters ranging from 3-5 mm. These newly developed correlations have been implemented into a heat exchanger simulation tool to predict performance, enable design, and conduct detailed analysis. An optimization study was conducted using a Multi-Objective Genetic Algorithm (MOGA) technique. This paper highlights the benefits of reducing tube diameters in tube-fin heat exchangers and illustrates an approach to design and optimize heat exchangers to meet a wide range of design criteria.
3 Correlating Swirl Behavior in Low Reynolds Number Flows in Wavy-Fin Heat Exchanger (LV-17-C082)
Sinusoidal wavy fins can help enhance heat transfer in plate-fin heat exchangers and thus improve the performance of compact heat exchangers in many different industrial areas like air-conditioning, heating, and waste-heat recovery. Besides increasing the surface area density of the heat exchanger, implementing sinusoidal wavy fins in plate-fin heat exchangers can also augment the convection heat transfer coefficient by generating swirls in the trough regions of the channels. In this study, single-phase, periodically developed, laminar forced convection in sinusoidal wavy-plate-fin channels is considered, with the corrugated plates subjected to uniform wall temperature.
4 Computational Study of Laminar Flow Heat Transfer Characteristics of Offset Strip Fin Channels (LV-17-C083)
Offset strip fins are used to increase the heat transfer coefficient as well as heat transfer area in compact heat exchangers. The formation and disruption of boundary layer takes place periodically in offset strip fins yielding high heat transfer coefficient, especially near the leading edge of each periodic portion. To characterize these effects, a computational study of flow and heat transfer in offset strip channels is performed. The Reynolds number in the laminar range (10 < Re < 2000) is considered and a range of Prandtl number is considered. A parametric study is also performed.
11:00 AM-12:30 PM
Conference Paper Session 22
Refrigeration Systems and Low GWP Refrigerants
HVAC&R Systems and Equipment
Emperors II (Caesars Palace Las Vegas)
This session includes five papers on advances in refrigeration systems and low global warming potential refrigerants. The first paper introduces a new type of refrigerant pressure sensor, a chip capable of operating at the required temperature and pressure ranges and compatible with the fluids used in these systems. The second and third papers present promising test results on the performance characteristics and chemical stability of next generation refrigerants, as replacements for R123. The fourth paper presents the performance gains achievable in DX systems using controls that continuously adjust refrigerant charge. Finally, the fifth paper presents modeling results on the global warming impacts of four types of supermarket refrigeration systems.
1 Assessment of Next Generation Refrigerant R514A as Replacement for R123 in Centrifugal Chillers (LV-17-C085)
R123 has been used successfully as a low ODP replacement for R11 since the ban on R11’s production after December 31, 1995, imposed by the Montreal Protocol. However, the Montreal Protocol ban on use of R123 after December 31, 2019, in developed countries is becoming imminent. This paper provides a description of the environmental and thermodynamic characteristics of R514A as a replacement for R123. The thermodynamic properties of R514A result in comparable performance to R123. The performance of two centrifugal compressor-based chillers was measured in laboratory tests with R123 as a baseline and with R514A as a replacement.
2 Chemical Stability Assessments of R-514A and R-1233zd(E) (LV-17-C086)
As the phase-out date for R-123 in approaches, alternative low pressure refrigerants are being identified and qualified for use in new and existing chiller products. This paper summarizes chemical stability evaluations that were conducted in the laboratory and in operating equipment to evaluate the system chemistry of refrigerant alternatives R-514A and R-1233zd(E). Chemical stabilities of refrigerants 514A and 1233zd(E) were proven to be similar to or better than R-123, and both refrigerants have been qualified for application in a range of centrifugal compressor-based chiller products. R-1233zd(E) has higher operating pressures than R-123 and is applied in new equipment designs.
3 Continuous Tuning of Refrigerant Charge to Improve DX Equipment Performance (LV-17-C087)
This paper reports on laboratory and field investigation of the effect of refrigerant charge level on DX packaged air-conditioner electric power demand, cooling capacity, and energy efficiency. In the laboratory, numerous performance parameters were analyzed as refrigerant charge level was incrementally adjusted above and below the manufacturer nameplate charge amount at a range of operating conditions. Automated charging controls along with performance monitoring systems were installed on package units at field sites in three climate zones: 3A (temperate-humid), 3B (hot-dry), and 2A (hot-humid).
4 Modeling of Total Equivalent Global Warming Impacts of Supermarket Refrigeration Systems (LV-17-C088)
Supermarket refrigeration systems are large contributors to greenhouse gas (GHG) emissions, which impose ever-increasing and global environmental concerns. It is important to quantify the GHG emissions that occur over the lifetime of supermarket refrigeration systems, for baseline refrigerants and systems, as well as for newer, low-global warming potential (low-GWP) refrigerants and systems. A commercially available simulation tool was used to model four refrigeration systems in a large supermarket, in two locations in California. GHG emissions from direct refrigerant release and indirect emissions due to energy consumption were considered.