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Natural gas combustion to serve space heating hot water systems causes approximately one third of large commercial building energy use in California. This project evaluated an innovative set of non-proprietary, cost-effective methods to reduce energy consumption and associated emissions from these systems. The project demonstrated 70% natural gas savings and substantial electricity savings in two large office buildings, yielding total utility cost savings of approximately $110,000 (or $0.5/ft²) per year. The project also conducted detailed studies on distribution losses and boiler efficiency in several buildings; measured performance of key components in laboratory tests; gathered and analyzed data from hundreds of buildings to evaluate actual performance of these systems; and provided a public dataset to inform future retrofits, research, and code development. The research also highlighted characteristics that make a building a good candidate for retrofit so these results can be scaled. Market transformation activities included 10 journal and conference publications, policy recommendations and a design guide. Based on these findings and other recent work, the opportunity for similarly large emissions reductions appears to be common within the existing large commercial building stock. The resources provided by this project can aid stakeholders in achieving California’s goals to decarbonize buildings.

Variable air volume systems with hydronic reheat at terminal units are a common Heating Ventilation Air Conditioning (HVAC) system type in medium and large commercial buildings. This study measured HHW heat loss in detail in a 66,000 ft2 (6,200 m2)​ office and lab building, built in 2000, in Davis, California. We used methods adapted from Raftery et al. (Raftery, Geronazzo, et al. 2018) to calculate the HHW distribution losses from BAS measured data, and then measured unintentional heat loss at the whole building level including losses from distribution and passing HHW valves. We further measured HHW distribution losses in greater detail on a single HHW distribution branch removing loss contributions from other potential issues, such as passing HHW valves.For the whole building, using newly installed, calibrated water flow meter and matched pair calibrated RTD HHW supply and return temperature sensors, typical HHW setpoints, with all air handlers turned off, the steady-state unintentional heat loss was 4.4 W/m2 (1.4 Btu/h.ft2) when all VAV terminal unit HHW valves were commanded shut, and 3.2 W/m2 (1.0 Btu/h.ft2) when one HHW valve was commanded open.Focusing on one HHW branch, during normal building operation over a two-month period in the heating season, we used BAS readings for air flow rate, supply air temperature, and discharge air temperature and measured a distribution heat loss of 2.86 W/m2 (0.91 Btu/h.ft2) and 40% HHW distribution efficiency. Using separately installed, calibrated temperature sensors yielded a similar result (2.43 W/m2 (0.77 Btu/h.ft2), 49%), and further correcting air flow rates with passive flow hood single point calibration of BAS reported flow rates also yielded a similar result (2.76 W/m2 (0.87 Btu/h.ft2), 42%). The close agreement between the results using BAS and calibrated sensors suggest that existing buildings can be screened for heat loss reduction interventions using only BAS data.The magnitude of the measured HHW losses are small compared to design day loads, but they occur for a large number of hours so reducing these losses can save substantial energy. Further, during the cooling season the losses both waste heat and increase cooling loads. Paths forward include adopting aggressive heating hot water supply temperature resets, reducing unnecessary reheat operation, improving HHW pipe insulation practices, and/or changing design strategies to seasonal switchover or electrically driven distributed systems such as electric resistance or terminal unit heat pump equipment.

The increase in extreme weather conditions and greater penetration of intermittent renewable energy, such as solar and wind,have resulted in electric grid balancing challenges, and greenhouse gas emissions remain high during peak hours. Residentialload flexibility programs help mitigate these challenges by shaping the electricity demand of major appliances to better matchgrid-level renewable electricity generation profiles. This study evaluates the load flexibility of a multi-function heat pump(MFHP) system responding to a dynamic price signal. The residential MFHP uses a single air-source heat pump outdoor unitto efficiently meet both water heating and space conditioning needs. The MFHP does not require electric resistance heatersfor emergency heat or defrost, potentially avoiding the need for electrical panel upgrades commonly required when replacinggas appliances. A 14 kW (48 kBtu/h) MFHP system is installed in an occupied residential building in California. To achieveload flexibility, a rule-based control algorithm adjusts water heating and space cooling setpoints with the objective ofminimizing electric energy cost in response to the dynamic price signal. Model-based control approaches require training dataand forecasting, increasing the complexity and commissioning time. The simplicity of this rule-based control approach will beeasier to adopt for widescale use because it has lower computational complexity, works with equipment from differentmanufacturers, and does not require in-depth programming and commissioning. The dynamic price signal used by thealgorithm consists of a forecast of hourly prices for the next 24-hour period. The rule-based algorithm determines hourlysetpoint schedules for the next 24-hour period based on the dynamic price signal for the water heating and space conditioningand communicates them to the MFHP thermostats.

Thermal end uses dominate building energy consumption and are a major driver of peak demand. As heating is electrified, peak electrical power required will surge, prompting a need for innovative HVAC system designs and controls.These designs must incorporate novel technologies at the component level and new integration techniques at the system level. One such possibility involves the addition of thermal energy storage (TES) in heating and cooling equipment using a phase change material (PCM) heat exchanger. Here, thermal energy storage via phase change can be used to shift the HVAC system loads to times of lower electricity cost, reduced carbon intensity, and greater energy efficiency. Most of the current utilization of PCM in buildings involves passive components. By actively controlling when heat is stored and released from PCM, we can optimize the building HVAC system to cost-effectively meet consumer needs with the flexibility to draw on renewable energy resources when they are abundant and available.While this combination of technologies is promising in theory, simulation-based evaluation of a prototype can be difficult due to the modeling requirements at the component level and the large number of possible configurations and operating modes at the system level. To conduct this evaluation, we use the Modelica language for modeling and simulation because it enables users to represent the important physics of the problem, interchange and rearrange components in an efficient manner, and implement a range of control configurations. In this work, we considered three case studies: a portable building, a large commercial retail store, and a multifamily residential apartment unit. Each of these employs a different system design, ranging from a single package vertical unit incorporating PCM to a central plant with independent heat pump, evaporative cooling, and thermal energy storage components. This paper describes the technologies in question, presents modeling at the component and system levels, and demonstrates building energy and demand charge cost savings with local time-of-use tariffs in a hot-dry climate.

Thermal end uses dominate building energy consumption and are a major driver of peak demand. As heating is electrified, peak electrical power required will surge, prompting a need for innovative HVAC system designs and controls.These designs must incorporate novel technologies at the component level and new integration techniques at the system level. One such possibility involves the addition of thermal energy storage (TES) in heating and cooling equipment using a phase change material (PCM) heat exchanger. Here, thermal energy storage via phase change can be used to shift the HVAC system loads to times of lower electricity cost, reduced carbon intensity, and greater energy efficiency. Most of the current utilization of PCM in buildings involves passive components. By actively controlling when heat is stored and released from PCM, we can optimize the building HVAC system to cost-effectively meet consumer needs with the flexibility to draw on renewable energy resources when they are abundant and available.While this combination of technologies is promising in theory, simulation-based evaluation of a prototype can be difficult due to the modeling requirements at the component level and the large number of possible configurations and operating modes at the system level. To conduct this evaluation, we use the Modelica language for modeling and simulation because it enables users to represent the important physics of the problem, interchange and rearrange components in an efficient manner, and implement a range of control configurations. In this work, we considered three case studies: a portable building, a large commercial retail store, and a multifamily residential apartment unit. Each of these employs a different system design, ranging from a single package vertical unit incorporating PCM to a central plant with independent heat pump, evaporative cooling, and thermal energy storage components. This paper describes the technologies in question, presents modeling at the component and system levels, and demonstrates building energy and demand charge cost savings with local time-of-use tariffs in a hot-dry climate.

Previous research has shown that under-ventilation of classrooms is common and negatively impacts student health and learning. To advance understanding of contributing factors, this study visited 104 classrooms from 11 schools that had recently been retrofitted with new heating, ventilation, and air-conditioning (HVAC) units. CO2 concentration, room and supply air temperature and relative humidity, and door opening were measured for four weeks in each classroom. Field inspections identified HVAC equipment, fan control, and/or filter maintenance problems in 51% of the studied classrooms. Across 94 classrooms with valid data, average CO2 concentrations measured during school hours had a mean of 895 ppm and a standard deviation (SD) of 263 ppm. Ventilation rates (VRs), estimated using the daily maximum 15-min CO2 in each classroom, had a mean of 5.2 L/s-person and a SD of 2.0 L/s-person across 94 classrooms. Classrooms with economizers, with or without demand control ventilation (DCV), tended to have lower mean CO2. Improperly selected equipment, lack of commissioning, incorrect fan control settings and maintenance issues (heavily loaded filters) were all associated with under-ventilation in classrooms. Many classrooms in this sample were frequently too warm to support learning. There were 23 out of 103 classrooms that had indoor air temperature above 25.6 °C for more than 20% of the school hours. Better oversight on HVAC system installation and commissioning are needed to ensure adequate classroom ventilation. Periodic testing of ventilation systems and/or continuous real-time CO2 monitoring (either as stand-alone monitors or incorporated into thermostats) is recommended to detect and correct ventilation problems.

A humanoid robot is a particular form of embodied agent. The form that an agent takes has a major impact on how that agent interacts with its environment and how it develops an understanding of that environment through its interactions. In this paper, we explore the importance of humanoid embodiment and we argue that humanoids occupy a special niche in the spectrum of robot forms. In doing so, we highlight the implications for the way a humanoid robot can interact with its environment, including humans, for the manner in which humans interact with humanoid robots, and for a humanoid robot's capacity to develop cognitive abilities. We also consider the degree to which humanoid robots should approximate humans, addressing robot morphology, appearance, and movement. We emphasize the dual role of humanoid robots as engineering artifacts that can provide services for humans, and as platforms for scientific enquiry into the nature of human cognition. We conclude by highlighting some key research challenges for the discipline of humanoid robotics. [ABSTRACT FROM AUTHOR]

Proceedings of the ASME 4th International Conference on Fuel Cell Science, Engineering and Technology, Irvine, CA, June 19 - 21, 2006Hydrogen can be produced in a variety of methods including steam-reformation of hydrocarbon fuels. In past studies the quasi non-dimensional space velocity parameter (inverse residence time) has been shown to be insufficient in accurately predicting fuel conversion in hydrocarbon-steam reformation. Heat transfer limitations have been manifest with reactors of different geometries. In order to achieve ideal fuel conversion, the heat transfer limitations and the changes of these limitations with respect to geometry must be considered in the reactor design. In this investigation, axial and radial temperature profiles are presented from reactors of different aspect ratios while holding space velocity constant. Using both the temperature profile information as well as the traditional space velocity limitations one may be able to develop an optimal reactor design.

Abstract: Precall represents improved memory for material practiced after the recall test. Such behavior has been suggested to serve the needs/motives of the individual. However, attempts to examine this have [...]

Robot-Assisted Therapy (RAT) has successfully been used to improve social skills in children with autism spectrum disorders (ASD) through remote control of the robot in so-called Wizard of Oz (WoZ) paradigms.However, there is a need to increase the autonomy of the robot both to lighten the burden on human therapists (who have to remain in control and, importantly, supervise the robot) and to provide a consistent therapeutic experience. This paper seeks to provide insight into increasing the autonomy level of social robots in therapy to move beyond WoZ. With the final aim of improved human-human social interaction for the children, this multidisciplinary research seeks to facilitate the use of social robots as tools in clinical situations by addressing the challenge of increasing robot autonomy.We introduce the clinical framework in which the developments are tested, alongside initial data obtained from patients in a first phase of the project using a WoZ set-up mimicking the targeted supervised-autonomy behaviour. We further describe the implemented system architecture capable of providing the robot with supervised autonomy.