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Pressures on building designers are rapidly shifting as renewable energy dominates new supply, as the electricity end-use consumer becomes more integrated into the energy supply structure, and as buildings become increasingly needed to shelter in place. Features of this new generation of standard design include thermal resiliency to better ensure occupant safety, comfort, and health in power outages, buildings that can operate with low or no greenhouse gas emissions, and systems that can interact with electricity grids increasingly dependent on variable renewable power. The rapid pace of change dictates that codes and standards should be developed that can ensure that these future-proofing design are widely vetted and documented to guide standard practice construction. Codes and standards can do that. This paper will consider how work underway in ASHRAE Standards 189.1, 227p, 228p and IEEE Standard 1547 as well as in market facing programs such as Passive House, is beginning to standardize some of these key changes in design practice. The paper then proposes that IECC and ASHRAE 90.1 are uniquely positioned for comprehensive regulatory strategies that engage these and other standards to meet the new challenges. By establishing measures for new construction and existing buildings in the nation’s model energy codes, these stalwart documents can ensure that buildings are designed for a paradigm most relevant to their use: not relying on the decades old energy code paradigm now on the books, but rather looking forward to meet the needs of owners, occupants, and the communities in which they are located. [ABSTRACT FROM AUTHOR]

Buildings are becoming more efficient and more renewable energy is coming online every day. These trends are being driven by market forces, as well as aggressive climate and energy efficiency policies, in jurisdictions across North America. Major changes to the grid will occur, and in some places already are occurring, due to major changes to the energy supply mix (mainly, more wind and solar energy). Because wind and solar are intermittent resources (and their supply-side generation profiles are often not easily aligned with demand-side load profiles), building-grid harmonization is becoming more important on both sides of the meter. The specific operational needs of the grid, and the emissions impact of energy consumption, vary increasingly by location, season, and time of day. In general, it is becoming clear that buildings have an important, and growing, role in catalyzing the clean, reliable, affordable, and safe operation of the electricity grid. Energy codes and building standards have an important role in ensuring that buildings help, rather than impede, building-grid harmonization. This paper examines a selection of energy conservation measures that shape, shift, or otherwise modify the building's demand profile to support building-grid harmonization. This set of measures is used to demonsrate how energy conservation codes can begin to incorporate these additional grid-based values into energy code scopes and metrics. The paper builds out a framework to ensure that energy codes can consider building-grid harmonization benefits in a productive manner based on five principles for code applications to grid integration measures. Guided by these principles, the paper explains the conceptual framework, including a formula for calculating total design load credits in a building, and identifies specific opportunities for code compliance enhancements. For example, energy modeling could support a sensitivity analysis to identify specific high-priority, high-impact code modification/update options (e.g. equipment, physical features of buildings) that could be used to develop a matrix of credits that could be traded in the code. Performance-based pathways are also considered. The paper discusses ways in which load management measures can be commissioned and verified to ensure predicted performance. Finally, the paper discusses recommended research and next steps. The foundational analysis and code framework laid out in this paper will help codes to remain relevant and impactful as building-grid interactions, and the grid itself, continue to evolve. [ABSTRACT FROM AUTHOR]

This paper, concerned with the low and ultra-low-temperature district heating goals of several countries for decarbonization, reveals the temperature mismatch between existing heating and cooling equipment and the thermal supply. The industry and the energy sector aim to resolve this conflict by total electrification with renewables and heat pumps for temperature peaking and, or equipment oversizing. This study shows that both measures defeat the purposes of decarbonization and quantify the carbon dioxide responsibility in embodiments and during operation according to exergy destructions. It has been concluded that widely available but with low exergy waste and solar energy resources can be mobilized for decarbonization in the building sector only with temperature-compatible heating and cooling terminal units minimizing the temperature mismatches. In this respect, a new panel radiator with heat pipe technology, which can satisfy indoor thermal loads with supply temperatures as low as 35oC (95oF) and sensible cooling loads as high as 19oC (292 K, 66.4oF) with little oversizing, is introduced. Test results from the ASHRAE Standard 138 are discussed. [ABSTRACT FROM AUTHOR]

Urban building energy modelling (UBEM) plays an essential role in the global climate action plans by analyzing the energy supply at urban or city scales and estimating the energy demand and the gas emission of different sectors. Moreover, policies and measures such as clean grid strategies, demand response programs, and dynamic pricing policies, that have been put in place as part of these plans rely heavily on the results of UBEM models to represent more realistic energy use and environmental impact at different temporal and spatial scales. However, the unsolved performance gap issue (i.e. discrepancy between the model predicted results and the actual performance) stands in the way of the effectiveness and the reliability of the developed models. One of the most acknowledged reasons behind such an issue is the uncertainty in modelling occupants' behaviours (OB) in this context. Therefore, many research efforts focused on investigating different modelling approaches to improve the level of details of occupant-related features in UBEM models. However, the capability of the developed models to be integrated into the currently available UBEM tools is still questionable. This caused many practitioners and UBEM users to rely on simple fixed schedules instead of examining stochastic models with a higher level of detail when needed. To this end, this paper aims to review the currently available OB models and compare them with respect to inputs, used algorithms, their expected outputs, as well as their integration capability into the commonly used UBEM tools. The results of this investigation can be used to develop guidelines for modelling OB aspects for the different applications of urban building energy simulation, as well as identify areas of improvement in the commonly used UBEM tools. [ABSTRACT FROM AUTHOR]

Electricity is used in almost all homes, and electricity accounted for 41% of household end-use energy consumption in 2019. Demand-side management of residential buildings, including heating, ventilation, and air conditioning (HVAC), home appliances such as refrigerators, washer/dryers, lights, and behind the meter (BTM) distributed energy resources (DERs) such as photovoltaic (PV) and battery energy storage system (BESS), play a critical role to alleviate the pressure on grid stability and reliability. The Texas power outages in February 2021 have highlighted the urgent needs to systematically engage demandside flexible loads and customer-generators such as BTM DERs in bridging the gap between power demand and supply. This is vitally important in extreme weather conditions, which may lead to an extensive power outage (e.g., Texas in February 2021). The combination of PV and BESS is identified as a potential opportunity to tackle this scenario. However, the design of specific control sequences is challenging because multiple components are engaged in this complex system. To address this gap, this paper is to exploit a small BESS integrated demand-side solution for residential buildings in Texas under extreme weather events (e.g., winter storms or heat waves) through a systemic analysis. We propose an adaptive model predictive control (MPC) platform to assist residential buildings with PV and BESS in improving the building resilience under normal and extreme weather conditions. During normal demand response, the adaptive MPC platform can minimize building owner's bills while maintaining occupant's thermal comfort. During demand response to an extreme weather event, it can provide optimal operation schedules with the consideration of peak demand limits and relax constraints of building operation needs. Some preliminary results show that at least 70% resilience improvement is achieved in terms of Unmet Degree Hour (UDH). [ABSTRACT FROM AUTHOR]

In 2019, the UK became the first major economy to pass laws to reduce its greenhouse gas emissions to net zero by 2050. Meeting this ambitious target not only requires a shift in energy supply from fossil fuels to low carbon energy sources, but also a reduction in energy demand through the roll-out of energy efficiency improvements to existing buildings. The UK has some of the oldest and most inefficient housing stock in Western Europe and the building sector is responsible for approximately half of energy consumption. The present work has a strong focus on exploring low carbon heat supply tehcnologies could be applied to existing housing stock, using the London Borough of Islington (LBI) as a case study. The applicability of low carbon energy efficiency measures to a range of different building archetype prominent within LBI is discussed and evaluated. The methodology implemented includes both qualitative and quantitative assessment of the opportunities and benefits, with a focus on applicability, cost, and carbon savings associated with two low carbon heat supply options. The overall evaluation approach presented in the paper is applicable to other urban areas in the UK and elsewhere. Key conclusion from the study and planned next steps are also discussed. [ABSTRACT FROM AUTHOR]

The current generation of building energy codes was born in the 1970s and 1980s, amidst a backdrop of the 1973 Arab Oil Embargo and the perception of limited worldwide energy resources. The intent of energy codes has been rooted in conservation of resources. Several factors including global climate change and the shale gas revolution have changed the picture fundamentally. It now has become critical that energy codes must reduce carbon emissions from the buildings sector. This paper follows upon a recently published paper examining how climate policy now impacts energy code policy. A variety of drivers, including greenhouse gas emission goals, regulation, market forces, and new technologies, is changing the relationship between buildings and the grid. As this relationship evolves, it is increasingly important to find metrics that enable useful and clear comparisons at the national level, while remaining regionally relevant. Similarly, it is increasingly important to move beyond annual metrics and find a way to consider hourly or other granular time scale impacts. Some leading jurisdictions, including California and New York, are currently working to resolve these issues; this paper includes an examination of those ongoing efforts. By encouraging building designers to consider hourly and regional building-grid implications, these metrics can support more distributed generation integration and reduced carbon impacts. This provides a benefit to the building and also enables the building to support the grid. Through updating the code basis metrics for buildings, model energy codes can play an important role in achieving jurisdictional carbon goals. This paper lays out new metric terms for model energy codes to move beyond their current basis and better align with current and future priorities, including consideration of the impacts and mechanics of those metrics. The authors provide specific recommendations concerning model code basis options, metrics, and mechanics; consider technical challenges to implementation and some potential solutions; and discuss first-order impacts that these code basis considerations may have on building design. [ABSTRACT FROM AUTHOR]

The climate crisis currently being faced by humanity is going to increase extreme weather events which are likely to make long-duration power outages for communities increase in frequency and duration. Microgrids are an important part of electrical resilience for connected communities during power outages. They also can have transactive potential to save energy on electric loads through coordinating distributed energy resources. Microgrids are expensive though. Making electric load coverage available nearly 100% of the time given known design basis threats and component failure statistics is one of the largest drivers of cost. Such high availability is non-negotiable for critical applications such as life saving equipment in a hospital but could perhaps be compromised for less critical loads. This paper documents an analysis that used the Microgrid Design Toolkit and EnergyPlus simulation results with two energy retrofit options exercised. The results show how increasing energy efficiency and reducing availability to 90% and 80% reduced the calculated price of a photovoltaic and battery storage microgrid in a New Mexico neighborhood by 63% and 70%, respectively. A microgrid with 80% availability with 48-hour islanded run-time capability is therefore suggested as a low-cost method for accelerating microgrid infrastructure penetration into the residential sector. Such an "underbuilt" microgrid will significantly increase resilience even though it will not guarantee energy security for the non-critical applications in residential households. This will in turn accelerate the growth of storage potential across communities providing greater grid flexibility. The results of the study also show how increased insulation applied to the proposed residential community can be less expensive than creating a larger microgrid that carries larger electric loads. The likelihood that energy retrofits are a better investment than a larger microgrid is inversely proportional to availability. Here, availability is a metric equal to the percentage of the demand load served by the microgrid during power outages, not including the startup period. [ABSTRACT FROM AUTHOR]

Many countries have committed to zero carbon emissions by 2050 and have set ambitious targets for net-zero energy buildings in the coming years. To achieve this goal, highly insulated envelopes need to be combined with renewable energy generation. Energy conservation measures (ECM)s are needed as practical steps toward higher energy efficiency. At the same time, it is important to consider the building occupants’ interaction with the energy supply and distribution systems as well as the control of thermostats, window openings, shading systems, or similar. Quantifying the occupant-related effects on the building energy can help to improve the building performance accuracy and reduce grid electricity stress. This paper proposes an automated workflow for analyzing the retrofits of non-residential buildings and the impact of their usage. The methodology is structured to follow three consecutive steps: (1) Extracting and modifying a Geo-based geometry model and assign attributes; (2) Energy modeling setup and parametric investigation; (3) Evaluating multi-objective scenarios for a range of construction, usages, and occupancy patterns. The methodology is applied to a case study on the re-use of an existing unoccupied industrial building complex located in Montreal, Canada, as part of a C40 re-inventing cities competition. The building geometry and surrounding context are processed and connected to an energy simulation software in order to examine a range of construction modifications, mechanical systems together with occupancy patterns. A construction and occupancy library has been developed to enrich the parametric investigation of the study. Various scenarios were investigated in a parametric process to guide design decisions for improved building performance. Different retrofit strategies that achieve the targeted objectives were compared in multiple aspects, such as energy, operational carbon, and embodied carbon. The presented workflow has the potential for expansion towards similar cases and building types. The methodology aims to support the decision-making for multiple stakeholders such as building owners, architects, engineers, and policymakers. Future investigations include developing a workflow that upscales the methodology to a broader spatial scale in a bottom-up approach. [ABSTRACT FROM AUTHOR]

Thermal energy systems’ resilience is especially important in extreme climates such as arctic or tropical environments. While metrics and requirements for availability, reliability, and quality of power systems have been established (DOD 2020), similar metrics and requirements for thermal energy systems are not well understood. In one of the first attempts to address this deficiency, a study was conducted to better understand the level of reliability required for energy supply systems that will be capable of supporting environmental conditions required for the facility’s mission, the comfort of people, and sustainment of a building in arctic environments under predominant threat scenarios. This paper is split into two parts. The purpose of Part I is to present the methodology and results of a novel temperature decay test conducted during the winter, along with blower door tests on five representative military buildings in Alaska. In Part II, a building modeling analysis is compared and calibrated to the experimental data collection for the thermal decay test (TDT) and a reliable building model that allows prediction of the maximum time available to repair the heat supply system before the building needs to be evacuated when damage is done to equipment or facilities is described. The results from the field tests described in Part 1 indicate that the rate of decay is dependent on the time of day (i.e., amount of sunlight) and building features, and will vary within the building relative to wind direction. This study, combined with the modeling analysis addressed in Part II, will provide guidance to building managers on evacuation and sustainment procedures for buildings in arctic climates that are affected by thermal energy supply systems, HVAC systems, fuel, or electrical disruptions. [ABSTRACT FROM AUTHOR]

Thermal energy systems’ resilience is especially important for extreme climates, such as arctic or tropical environments. While metrics and requirements for availability, reliability, and quality of power systems have been established (DOD 2020), similar metrics and requirements for thermal energy systems are not well understood. In one of the first attempts to address this deficiency, a study was conducted to better understand the level of reliability required for energy supply systems that will be capable of supporting environmental conditions required for the facility’s mission, the comfort of people, and sustainment of a building in arctic environments under predominant threat scenarios. This paper is split into two parts. The purpose of Part I is to present the methodology and results of a unique temperature decay test conducted during the winter, along with blower door tests on five representative military buildings in Alaska. In Part II, the modeling analysis is compared and calibrated to the experimental data collection for the thermal decay test (TDT). A reliable building model allows us to predict the maximum time available to repair the heat supply system before the building needs to be evacuated, when damage is done to equipment or facilities critical to the building operations, or when damage is done to the building itself. This will provide guidance to building managers on evacuation and sustainment procedures for buildings in arctic climates that are affected by fuel or electrical disruptions. [ABSTRACT FROM AUTHOR]

In recent years, physics-based building energy modeling (BEM) has started being used to evaluate the performance of buildings in the context of connected communities and on an urban scale to study their aggregated energy use, interactions, and impacts on the energy supply infrastructure and environment. The development of urban scale BEM solutions needs extensive effort. Existing attempts tend to focus on different aspects of BEM on an urban scale, such as collecting as-built building data from different information sources, integrating geometry modeling with geographic information systems (GISs), representing operational and occupancy profiles, automating workflow, processing and visualizing the results, and conducting large-scale simulations. Urban scale BEM development would benefit from multi-disciplinary research areas and from an open platform to adopt advancements on data sources and tools. For these purposes, this research proposes a modularized bottom-up model creation and simulation framework that is built on the state-of-the-art BEM tools and can accommodate different building stock data. This framework uses a standardized modeling inputs schema to describe building design and operational characteristics, and it can be instantiated from different building survey datasets with heterogeneous structures. The paper presents a case study of the proposed framework that demonstrates how thousands of surveyed buildings from the 2012 U.S. Energy Information Administration's Commercial Buildings Energy Consumption Survey (CBECS) were one-to-one converted to EnergyPlus models through the schema and the model generation process, then simulated efficiently with distributed computing, and their simulation outputs aggregated to show satisfactory results. [ABSTRACT FROM AUTHOR]

The energy supply in Austria was first established in the 1880s with regenerative microgrids for industries and public buildings. These were unified and modernized step by step to form what is now one of the most reliable power supply systems in the world. A large share of more than half of the power production comes from hydro power stations, many of which also provide pump storage. Since the 1950s, previously wasted heat from fired power stations has been distributed to dense urban areas via district heating. Oil price crises, rising awareness for environmental issues, and increasing availability of incinerable waste have led to a diversification of fuel and inclusion of geothermal heat and waste heat from industrial processes. Public buildings and communities were at the start of the Austrian modern energy supply system, and with growing demand for transformation of energy supply to meet net zero requirements, today they serve as models for the future. Thus, the efforts and methodology applied on Austrian university campuses are presented here as a result of the Austrian Research Promotion Agency (FFG) Project 864147, funded by the Austrian Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology, to contribute to the International Energy Agency Energy in Buildings and Communities Programme (IEA EBC) Annex 73, Towards Net Zero Energy Public Communities, which focuses on developing guidelines and tools that support the planning of net zero energy resilient public communities. Two case studies illustrate the transition towards net zero resilient energy: • Case Study 1: The Campus Technik of University of Innsbruck, where building envelopes and building technology have been modernized to reach an energy consumption close to what is achieved in high-quality new construction, with inclusion of heat regeneration from ventilation and use of ambient cold for night ventilation. • Case Study 2: The new campus of Wirtschaftsuniversität (WU) Wien, which uses groundwater heat in a cyclic way both for heating and cooling, where core activation allows for mostly direct use without the need for heat pumps to adapt temperature levels. This paper briefly describes the specific Austrian situation of legislation, tradition, and policy that creates the framework for changes towards net zero energy supply. The two case studies illustrate how this framework has been handled by the planning teams to meet the objectives in the most cost-effective way and how challenges have been dealt with and successfully overcome. [ABSTRACT FROM AUTHOR]

This paper presents two simple cooling coil models. The first part of the paper describes and validates the first one ("reference model"). This model only necessitates 3 parameters, which can be estimated by using commissioning or manufacturer information. The second part of the paper presents and validates the second simple model ("simplified model"). The paper shows how the latter can be built from the reference model, when there is no need to describe what happens on the refrigerant side. This simplified model can be easily integrated in the model of a global HVAC system in order to calculate the cooling coil energy consumption over large time periods. The simplified model is appropriate to decrease the computational time and avoid numerical instabilities. [ABSTRACT FROM AUTHOR]

This paper describes the implementation of external coupling between building energy simulation and CFD. Internal coupling is the "traditional" way of developing software. i.e., expanding the capabilities of existing software by adding new modules into an existing package. External coupling, on the other hand, makes use of existing packages in different domains (for example, the thermal domain for energy simulation and the flow domain for CFD) and provides a mechanism for these packages to communicate. A summary of the latest development is presented to put external coupling into the context. The implementation of external coupling is then summarized. The paper concludes with a case study to validate the performance of external coupling, and to highlight its potential. [ABSTRACT FROM AUTHOR]

The Fort Carson, CO, Combat Aviation Brigade (CAB) complex is a proposed 60-building development originally planned as a grouping of individual structures, each with its own boilers and chillers. None were to be engineered to share energy resources with neighboring structures. After the initial planning for the CAB, the US Army named Fort Carson as one of eight pilot net zero installations for energy use as a part of the Army's overall effort to conserve resources. Fort Carson's goal for the CAB complex at Butts Army Airfield consequently became the construction of a "net zero ready" community of buildings designed to optimize energy performance, water conservation, and waste diversion. The US Army Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) conducted a study to assess the potential for synergy between CAB facilities energy needs and the feasibility of building a Central Energy Plant (CEP) that would produce hot and chilled water to be used for heating and cooling throughout the CAB complex, and that could also generate electricity through cogeneration. This paper describes the results of the study and different alternatives considered, as well as energy requirements and specific technologies that have been applied to this new generation of buildings. [ABSTRACT FROM AUTHOR]

Community-scale energy planning represents a multidiscipline problem involving the competition of many economic, environmental, energy security, and logistical requirements. This complex problem is routinely faced by U.S. military installations, both domestic and abroad, and can result in unnecessary financial and personnel costs if a suboptimal solution is chosen. In response to this problem, the U.S. Army Corps of Engineers (USACE) has developed a community-scale, mixed-integer linear programming (MILP) based model to assist in the selection of energy supply and distribution equipment and to determine optimal schedules of operation. The model was developed to minimize the total annual equivalent cost of providing thermal and electric power to clusters of buildings by selecting from existing or potential equipment using a fully centralized, fully decentralized, or hybrid approach, while meeting all other required constraints. This paper describes the model (with an emphasis on its unique elements in relation to similar existing models), its limitations, and considerations for future work. [ABSTRACT FROM AUTHOR]

Renewable energy generated by sources like wind and solar is unpredictable. Sometimes the renewable energy is available when it's not needed and vice-versa. These resources ramp up or down very quickly depending on the weather -- wind gust will rapidly increase the output from a wind farm or a cloud cover will decrease output from a photovoltaic installation. Integrating these renewables in the electricity grid is a challenge for the grid operators who are always trying to balance supply and demand of electricity. Currently utilities and grid operators use existing generating assets and ramp them up or down to balance this fluctuating generation. This ramp up and down causes wear and tear as well as maintenance issues on expensive generating assets. End-use thermal devices like water heaters offer an existing and a cheaper resource to help balance load and generation. This paper presents analysis of a utility SCADA (Supervisory Control and Data Acquisition) data. Total load on the system, output from each generator on the system and frequency are presented. The results show the effects of wind on the system, particularly on the generators that are used to balance the load and generation. With twice as much wind coming online by end of 2012 in this particular utilities territory, wind integration is high priority for the system operators. A discussion on how residential electric resistance water heaters can help mitigate the issues related to wind integration is also provided. This same analysis can also be applied to other intermittent renewable generation. [ABSTRACT FROM AUTHOR]

The increase in demand for enhanced building performance is becoming a challenging task to fulfill especially during buildings operational phase. This situation creates the need for the development of new process controls for buildings operations to achieve the goal of a completely intelligent building which is able to respond dynamically to internal and external perturbations in order to foster comfort conditions for the building occupants. Unpredictable user-behavior, changing weather conditions, mismatch between consumption and production of resources, operation of active and passive climate-control systems are factors that affect buildings behavior hence requiring the use of intelligent control decisions in real-time. These intelligent control decisions directly affect the buildings energy efficiency and occupant thermal comfort The road towards intelligent control decisions in real time for intelligent buildings operation requires groundbreaking innovations and progress beyond the current state-of-the-art in various aspect of building construction. In achieving the desired goals, the application of AI techniques promises to be very useful, especially multi agent systems which has shown enormous potential for improving the operational control of buildings. Up until now, there has not been any real application of intelligent agents in building management systems, however field tests with multi agent systems on top of current building management systems has shown to be a promising approach for combined cooperation between building management systems and the Grid. A further development is to implement MAS structures for comfort management in combination with energy optimization as an addition to existing building management functionality. In this paper, an ontology for open multi agent platform in combination with a Building Energy Management System is presented. [ABSTRACT FROM AUTHOR]

The developed world is increasingly energy constrained. There is an urgent need to reduce dependence on energy imports from unstable or unfriendly areas of the world and to increase the use of renewable energy technologies to meet our energy needs into the 21st century. In Europe the provision of a more secure energy supply is now the primary driver of energy supply and efficiency related policies. In the UK there are now explicit incentives for the use of technologies delivering heat from renewable sources: the Renewable Heat Incentive (RHI) and a mechanism for paying incentives for the installation of electricity generation equipment through the "Feed in Tariff". There is also a programme for the installation of energy efficiency measures in existing buildings which are initially funded by market packages, and these are then paid off over the following years from the reduced utility bills which the measures facilitate. There is also the European Union's Energy Performance of Buildings Directive, which has recently been updated and will require mandatory improvements to existing buildings as well as the setting of minimum standards of energy performance for new and existing buildings, with a target for all new buildings within the European Union to be "nearly zero carbon" by 2020. This paper will review the legal mechanisms being introduced to incentivise low or zero carbon technologies, or to require standards of building fabric performance that will reduce dependency on energy imports. It will discuss the introduction of new standards for energy efficient dwellings, and will also detail the various technologies supported or encouraged and will also demonstrate the benefits offered by the various schemes. While it will focus on the UK experience, it will also draw on experience from the various schemes adopted elsewhere in Europe. [ABSTRACT FROM AUTHOR]

Shading devices are important design elements of glazed façades to reduce energy consumption of buildings and improve thermal and visual comfort of occupants. Although there has been significant development in the evaluation and modeling of the thermal performance of shading devices, current methodologies are limited to a few shading products and types. Furthermore, current fenestration thermal models do not account for radiation emission and absorption throughout shading layers, and allurements for energy generation and conversion imbedded in glazing layers. This paper presents a general methodology to compute the thermal performance of fenestration systems incorporating permeable shading devices and elements for energy generation and conversion. The methodology assumes each shading layer as porous with effective radiation and thermal properties. The effective properties account for the geometrical and thermal characteristics of the shading layer, and the effect of the convective heat transfer within the layer porous structure. Using the concept of the thermal penetration length, effects of porous shading layers on the convective heat transfer from their boundary surfaces to the adjacent gas spaces are also accounted for. A validation study is carried out, in which the U-factor of a double-glazed window with between-pane Venetian blinds are compared with the available laboratory measurement. The comparison results show that the model predictions are in good agreement with the measurement. [ABSTRACT FROM AUTHOR]

Traditional constant air volume systems consume significantly more energy than variable air volume (VAV) systems because a constant amount of air is supplied to each zone regardless of the zone load. Due to seasonal and daily load variations, variable frequency drives (VFDs) can be installed on these constant air volume systems to reduce system energy consumption without needing to retrofit the terminal box. This paper presents the procedures for supply fan speed control and the results of its application in an office building. The results show electricity savings of 23% and gas savings of 19% over a six-month period. [ABSTRACT FROM AUTHOR]

This paper discusses the implementation of new innovative technologies in a Continuous Commissioning Leading Energy Project (CCLEP). Results of a case study show that CCLEP implementation can improve building operations and reduce energy costs. Energy consumption is compared in detail before and after CCLEP. Results show average electricity savings of 26.8% and gas savings of 47.8%. [ABSTRACT FROM AUTHOR]

With the issuing of the recent Environmental Protection Agency (EPA) report to Congress (EPA, 2007), the issue of data center energy consumption is now a matter of intense industry focus. Key findings of the EPA report are that most data centers do not know what their energy efficiency is, and an equal number do not even know how to go about measuring such energy efficiency. Knowledge of a data center's energy efficiency is now considered a competitive advantage by many world-class companies. With funding from the Department of Energy, the Pacific Northwest National Laboratory (PNNL) has established its Energy Smart Data Center Test Bed (ESDC-TB), which is housed in a mixed-use facility. In the latest phase of this effort, PNNL has undertaken a major effort to instrument its ESDCTB, and the supporting facility, in order to quantify the energy efficiency of information technology (IT) equipment and infrastructure Under Test (ITUT), in real-time. In addition, PNNL has created a comprehensive software tool, FRED, to acquire, reduce, and display the power consumption of the various parts of the ESDC-TB and the supporting facility in real-time. FRED will soon have the capability to calculate and display the real-time energy efficiency of ITUT - the energy efficiency metric of choice is The Green Grid's Data Center Infrastructure Efficiency (DCiE). This paper describes these capabilities in detail and also describes how to quantify the ITUT's share of the total power consumption for major subsystems such as its facility chiller plant. [ABSTRACT FROM AUTHOR]

Conventional technologies based on use of fossil fuels significantly contribute to the environmental load. Increasing efficiency of heat supply, resulting in rational use of fossil fuels, is a primary condition of sustainable energy supply. This increase is limited by the validity of basic laws of thermodynamics. Moreover, regardless of the maximum effectiveness of fossil fuels' utilization, sustainability of the energy supply is limited to several decades. This paper describes some basic approaches to long-term sustainability under conditions of the European Union. The validity of these approaches is, however, universal and can be applied globally. [ABSTRACT FROM AUTHOR]

Building energy performance rating protocols provide a way to compare the energy consumption of one building with those of other similar buildings. A search found 47 protocols for commercial buildings, five of which were chosen for in-depth evaluation in this paper. The most common methodology used by the protocols chosen was to compare the building to a database of surveyed buildings. The comparison could be as simple as a graphical comparison of energy intensity, or it could be a complex procedure to compute an index. To compare the selected protocols, data on 29 buildings were gathered using a short survey. While some exceptionally good buildings are consistently rated well across different rating methods, most buildings could be considered "good" by some rating methods but not others. [ABSTRACT FROM AUTHOR]

Planning the information technology (IT) installation in a data processing environment is a cumbersome task Even though Thermal Guidelines for Data Processing Environments (ASHRAE 2004) addresses heat load planning, the electrical and thermal considerations go hand-in-hand. Using the correct electrical planning values can make the difference between either having adequate capacity or running out of finite power The question becomes, what is correct? This paper will examine terms like nameplate and power consumption with an explanation of how each term should be applied in the data processing environment. In addition, a minimum set of electrical and thermal specifications are introduced. Finally, strategies are provided on how to properly plan the electrical environment in tandem with the thermal environment for maximum energy efficiency. [ABSTRACT FROM AUTHOR]

Sustainability for datacom installations means providing the necessary cooling while using a minimum of energy, a minimum of water and with a minimum release of pollutants to the environment. Designing a system that maximizes the use of waterside economizers may be a way to achieve significant energy savings. This paper will examine three choices in evaporative cooling (open cooling towers, closed-circuit coolers, and hybrid water/air systems) and the benefits and issues with their operations in waterside economizer mode. In addition, advancements in non-chemical water treatment of the open loop in evaporative cooling equipment will be discussed. [ABSTRACT FROM AUTHOR]

The objectives of this paper are to determine if an energy wheel can improve indoor air relative humidity (RH) and perceived air quality (PAQ), as well as reduce energy consumption. The TRNSYS computer package is used to model an office building in four North American cities (Saskatoon, Saskatchewan; Vancouver, British Columbia; Tampa, Florida; and Phoenix, Arizona). The results with and without an energy wheel are compared to see if the energy wheel has a significant impact on the RH and PAQ in the building. The energy wheel significantly reduces peak RH levels in Tampa and Phoenix and has a smaller effect in Saskatoon. The energy wheel reduces the number of people that are dissatisfied with the PAQ within the space in these cities. By using an energy wheel, the total energy consumed by the HVAC system in Saskatoon, Phoenix, and Tampa is reduced. There is a significant reduction in the size of the heating equipment in Saskatoon and in the size of the cooling equipment in Phoenix and Tampa. A cost analysis shows that the HVAC system including an energy wheel has the least life-cycle costs in these three cities. In Vancouver, the energy wheel has a negligible impact on the indoor RH, PAQ, energy consumption, and life-cycle cost. [ABSTRACT FROM AUTHOR]

Recognizing that the energy-saving potential of combined heat and power (CHP) systems is underused, the Council of the European Union has issued a Cogeneration Directive. In terms of specific guidelines and rating parameters based on energy efficiency, the objective was to promote "high-energy cogeneration." This paper makes a critical review of the Directive using the rational exergy management model (REMM), which is a common sustainability metric that can better bridge the compound benefits of CHP systems with the environment. REMM is a common rationality metric, which is an indicator of how the supply and demand exergies in the energy sector are balanced. In this respect, the primary energy savings equation of the Directive was modified in order to factor in rational exergy benefits on the environment, which remained hidden so far. Sample calculations made in the Euoropean Union (EU) FP6 Research Project HEGEL show that the rational exergy benefits in conserving primary energy resources are 62% more than what the Directive can indicate. Using parametric analyses, this study draws a new roadmap for better and optimized cogeneration systems. [ABSTRACT FROM AUTHOR]

More than 200,000 homes are factory built in the United States each year to the federally preemptive Manufactured Housing Construction and Safety Standards, mandated by the U.S. Department of Housing and Urban Development (HUD-code). This paper analyzes national energy use and savings potential from improvements to thermal distribution system efficiency, thermal envelopes, and heating, ventilation and air conditioning (HVAC) equipment over what is currently required by HUD-code. Estimated energy savings over current HUD-code are provided for four cases: National Fire Protection Association Standard 501-2005 (NFPA 2005), the 2006 International Energy Conservation Code (IECC 2006), the U.S. Environmental Protection Agency's ENERGY STAR® manufactured housing guidelines (EPA 2004), and Best Practice, based on the U.S. Department of Energy's Building America Industrialized Housing Partnership program home built in the Pacific Northwest (BAIHP 2005; NEEM 2004). Savings estimates are also provided from improved HVAC system efficiencies such as using ENERGY STAR heat pumps in lieu of electric furnaces and ENERGY STAR air conditioners. Energy use and associated savings are provided in terms of both energy cost and source energy. [ABSTRACT FROM AUTHOR]

Numerous fault detection and diagnostic system techniques have been developed for HVAC systems, but most focus on detecting faults at the component level, for example, air-handling units or variable air volume boxes. This paper examines the use of the ASHRAE simplified energy analysis procedure (SEAP) for fault detection at the whole-building level. In the procedure examined, an implementation of the SEAP is "calibrated" to a period of measured heating and cooling data from a building so the simulated data closely follow the measured data. A small adjustment is added to the simulated data so the total adjusted simulated heating and cooling consumption values exactly match the measured heating and cooling consumption totals for the same period. The adjusted version of the calibrated SEAP simulation is then used to predict future consumption, using future weather data. Visual comparison with future measured data is used to diagnose significant deviations from expected performance. The procedure is applied retrospectively to three years of measured consumption data as a test. It clearly identifies three significant operational changes that occurred during the test period. Three different presentation formats are tested for fault identification—monthly deviations, daily percent deviations, and cumulative deviation plots. All have value, and it is ultimately a user preference as to which is the most informative. [ABSTRACT FROM AUTHOR]

A study of five "low-energy" schools in the UK shows that predicted CO2 savings are not consistently achieved. Four of the schools evaluated emitted more carbon emissions than the median UK building, and the fifth showed only marginally superior performance. This study used real consumption data, computer energy models, long-term light level samples, energy audits, and interviews with facility staff to draw its conclusions. Although heating energy consumption for these buildings was successfully reduced, electrical energy consumption was much greater than in the existing stock of schools. Obvious causes are the increase in the use of IT in schools, as well as more stringent internal air quality standards. Less obvious causes are lack of building management training for "intelligent" buildings, new regimes of usage in the buildings, and control strategies that default to equipment and lights being on rather than off. The paper calls for more post-occupancy evaluation to ensure that genuine low-energy buildings are produced. [ABSTRACT FROM AUTHOR]

This paper shows that the energy requirements for today's typical efficient window products (i.e., Energy Star™ products) are significant when compared to the needs of zero-energy homes (ZEHs). Through the use of whole house energy modeling, typical efficient products are evaluated in five US climates and compared against the requirements for ZEHs. Products that meet these needs are defined as a function of climate. In heating-dominated climates, windows with U-factors of 0.10 Btu/h·ft2·°F (0.57 W/m2·K) will become energy neutral. In mixed heating/cooling climates, a low U-factor is not as significant as the ability to modulate from high solar heat gain coefficients (SHGCs) (heating season) to low SHGCs (cooling season). [ABSTRACT FROM AUTHOR]

Because of their ability to improve building air quality and their potential to reduce energy usage in some climates by allowing more conditioned air recirculation, use of gas contaminant filters in buildings is increasingly considered. Air cleaning is an option under ASHRAE Standard 62 and is required if the outdoor air is poor. New media and processes are becoming available, and their performance needs to be evaluated. Further, evaluation of existing technologies needs to be standardized. Both small-scale and full-scale testing is required, and there is not a standard method for systematic evaluation of commercial full-scale gas-phase air cleaners in a duct. A number of laboratory tests of full-scale gas-phase air filtration equipment (GPAFE) have been conducted at RTI over several years. The methods were developed during ASHRAE and EPA research and refined on later commercial projects. The full scale test method uses a modified ASHRAE Standard 52.2 test rig. This paper presents an overview of fullscale GPAFE testing and discussion of the considerations that go into design of a full-scale test. Selected results of full scale tests are presented. [ABSTRACT FROM AUTHOR]

Energy savings performance contracts (ESPCs) are a method of financing energy conservation projects using the energy cost savings generated by the conservation measures themselves. Ideally, reduced energy costs are visible as reduced utility bills, but in fact this is not always the case. On large military bases, for example, a single electric meter typically covers hundreds of individual buildings. Savings from an ESPC involving only a small number of these buildings will have little effect on the overall utility bill. In fact, changes in mission, occupancy, and energy prices could cause substantial increases in utility bills. For this reason, other, more practical, methods have been developed to measure and verify savings in ESPC projects. Nevertheless, increasing utility bills—when ESPCs are expected to be reducing them—are problematic and can lead some observers to question whether savings are actually being achieved. In this paper, the authors use utility bill analysis to determine energy, demand, and cost savings from an ESPC project that installed geothermal heat pumps in the family housing areas of the military base at Fort Polk, Louisiana. The savings estimates for the first year after the retrofits were found to be in substantial agreement with previous estimates that were based on submetered data. However, the utility bills also show that electrical use tended to increase as time went on. Since other data show that the energy use in family housing has remained about the same over the period, the authors conclude that the savings from the ESPC have persisted, and increases in electrical use must be due to loads unassociated with family housing. This shows that under certain circumstances, and with the proper analysis, utility bills can be used to estimate savings from ESPC projects. However, these circumstances are rare and over time the comparison may be invalidated by increases in energy use in areas unaffected by the ESPC. [ABSTRACT FROM AUTHOR]

This paper outlines a phased retrofit plan for the central chilled water plant at Sonoma State University. The plant has experienced many operational problems and is composed of equipment (chillers, pumps) that has operated well beyond its expected service life. Furthermore, the campus master plan calls for the addition of several future buildings that will tax the already marginal capacity of the system. The retrofit plan, which includes converting the distribution system to primary-secondary/series-tertiary pumping, will enhance the plant capacity to serve future buildings, resolve existing hydronic distribution system problems, improve energy efficiency, reduce maintenance costs, and improve system reliability. [ABSTRACT FROM AUTHOR]

This paper provides an experimental evaluation of the efficiency of an energy recovery ventilator (ERV) for a range of summer temperatures in Ottawa including humid summer days. The assessment was achieved using the twin houses at the Canadian Centre for Housing Technology (CCHT) and their ‘side-by-side testing’ to measure the real impact of the installation of the ERV. ‘Side-by side testing’ consists of incorporating into the test house an innovative energy-saving component, in this case the ERV. Both houses are then operated identically and monitored. Changes in house performance due to the innovation are observed through comparison of test house performance to reference house performance for a range of weather conditions. The parameters that were compared for this study include airflow, energy consumption, house air temperature, and humidity. Incorporating an ERV into the test house in the summertime not only offered more efficient humidity control compared to the reference house with a heat recovery ventilator (HRV) but also showed a reduction in air-conditioning electricity consumption in particular and cooling electricity consumption in general. [ABSTRACT FROM AUTHOR]

This paper introduces the modeling of single-split coil room air-conditioning systems governed by modulating control action for use in building energy simulation. The model calculates energy consumption, sensible and latent cooling capacities of the split coil system at part-load operation, matching the sensible and latent cooling zone loads. As a result, the zone air states can be exactly determined. The model of the split system under two-position control has previously been developed and verified (Neymark and Judkoff 1998, 2000; Knabe and Le 2000a). Results of the simulation show a significant impact of the controller type on both room comfort (temperature and humidity) and energy consumption. [ABSTRACT FROM AUTHOR]

This paper documents an analytical study of a microturbine-based CHP system for a small commercial building. The flow exiting the microturbine turbine (exhaust) either enters the hot side of the microturbine recuperator or is allowed to bypass this recuperator for variable recuperation. While bypassing reduces the microturbine thermal efficiency. there is better matching of the CHP thermal and electrical outputs to the building thermal and electrical loads, respectively. Absorption chilling, hot water space heating, and domestic hot water heating are employed. The overall CHP system yearly performance is investigated for various CHP and microturbine operating modes. [ABSTRACT FROM AUTHOR]

Industrial plants use electrical power equipment to distribute power for lighting, driving motorized devices, operating HVAC equipment, and control of equipment. The main focus of this paper is to provide updated information on heat losses by various types of electric power equipment. The information is organized by equipment type, and practical guidance on using this information to compute losses under different conditions is provided. The effect of loading margin used by designers in sizing the electric equipment, load diversity, and ambient temperature on heat loss is discussed. Uncertainties in the results for different pieces of equipment are presented. Also, a comparison of the results to the previously published information is provided. [ABSTRACT FROM AUTHOR]