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Liquid Desiccant Air Conditioning and Dehumidification (LDAC) has been emerging in the past 10 to 15 years as an energy-saving alternative design for applications that require high moisture removal and a Cleantech solution that has the potential to provide significant energy savings when applied to more broad markets. Buildings are the primary users of electricity in the U.S., consuming about 75% of the total electricity produced and about 40% of all U.S. primary energy use and associated greenhouse gas (GHG) emissions. A substantial portion of that energy is used for air conditioning and dehumidification. Furthermore, the U.S. Department of Energy (DOE) reports that U.S. buildings account for 35% of the U.S. carbon dioxide emissions that drive the climate crisis. One specific application that requires significant moisture removal is the indoor cultivation of legal cannabis. It is estimated by the DOE that by the end of this decade, electrical energy usage by indoor cannabis operations will be on par with the electrical energy consumed by either data centers or for the recharging of electrical vehicles. More recent projections indicate cannabis sales are expected to double from 2021 to 2030. As such, more efficient and economical methods of climate control are necessary for more widespread application in cannabis operations to reduce the energy requirements. The added emphasis should be on methods to first reduce the energy required before building the electrical generating infrastructure to support such growing industries. Climate control of indoor cannabis cultivation is one such aspect where energy-efficient air conditioning and dehumidification can contribute to reducing the projected energy usage by end of this decade. This paper gives an overview of a standalone LDAC system and a hybrid LDAC combined with an air handling unit. This paper will present indoor grow room case studies from a side-by-side installation of a hybrid LDAC unit and Desiccant Wheel (DW) air handling system in two identical cannabis grow rooms. Integration with a Combined Heat and Power (CHP or cogeneration) plant onsite supplying energy for both the technologies will be examined. Further, comparative energy analyses of LDAC, DW technology, and other widely used technologies in the HVAC indoor growing environment will be discussed. This will be the first comprehensive, side-by-side performance and energy analysis of competing desiccant (LDAC and DW) technologies in a controlled, indoor agriculture environment. [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]

A considerable amount of literature on the application of inverse methods to building energy data has been published in the last three decades. These inverse models serve a variety of purpose such as baseline modeling for monitoring and verification (M&V) projects at monthly, daily, and hourly time scales; condition monitoring; fault detection and diagnosis; supervisory control; and load forecasting, to name a few. Usually, these models have distinct model structures, and separate models are developed depending on the specified need. This paper proposes a novel inverse modelingframework that attempts to unify some of the above application-specific models by allowing a single model to be incrementally enhanced. Specifically, we begin by clustering the energy interval data of a building, identifying scheduling day types and removing any outliers. This aspect of the analysis is described in the companion paper by Jalori and Reddy (2015). Subsequently, the first level is to identify models for each day type using daily average values of energy use and climatic variables; this is adequate in many M& Vprojects. These models are then extended to hourly time scales by including additional terms in the model that capture diurnal variations of the climatic variables and the building hourly scheduling about the daily mean value; this level is appropriate for M& Vand for condition monitoring. Finally, periodic autoregressive terms are added to the model to enhance prediction accuracy for short-term load forecasting, useful for demand response programs, or for short-term supervisory control. The application of the proposed methodology is illustrated with year-long data from two different buildings, one synthetic (the Department of Energy medium-office prototype) building and an actual office building. [ABSTRACT FROM AUTHOR]

Many supertall buildings that are over 984 ft (300 m) tall have been constructed in the Far East. Their fire protection systems only follow the current codes that are designed for tall buildings. People are worried whether fire safety provisions in supertall buildings are adequate. However, very few comprehensive studies on the dynamics of room fires in supertall buildings have been conducted. Fires in supertall buildings are subject to wind action and have a high heat release rate; their characteristics will be discussed in this paper. General aspects of supertall building fires will be reviewed first. Next, the heat release rate of burning combustibles in a supertall residential flat will be presented. The stack effect in supertall buildings will be estimated. The climatic conditions of three different cities will be used as references. The paper will also discuss the necessity of providing appropriate staircase pressurization systems. [ABSTRACT FROM AUTHOR]

Approximately ten years ago, ASHRAE embarked on a process to establish a standard to categorize climates in a way that could be used for Energy Standards and Codes. The work done on ASHRAE Standard 169 formed the basis for the climate zones that are currently used in ASHRAE/IES Standard 90.1, ASHRAE Standard 90.2, and the International Code Council's (ICC) International Energy Conservation Code (IECC). The 2013 version of ASHRAE Standard 169 is based on a more recent climate data set, and contains the first significant update to the initial version. This paper summarizes the changes in the 2013 version of ASHRAE Standard 169 as they relate to Energy Standards and Codes, and the potential implications of these changes for Standards 90.1, 90.2, and the IECC. On a global level, the number of thermal climate zones has been expanded from eight to nine. The existing Climate Zone 1 is subdivided into two overarching zones: "extremely hot" and "very hot". The new climate zone category includes the hottest regions in the world. The "extremely hot" climate zone encompasses a huge swath of highly populated areas. The humid portion of the extremely hot climate zone includes over 250 weather sites within over 60 countries. The dry portion of the extremely hot climate zone includes more than 75 weather sites within 20 countries. Consequently, the building envelope and mechanical systems criteria in Standards 90.1, 90.2, and the IECC would need to be re-evaluated in light of this new categorization. On a national level, a number of U.S. counties are assigned to different climate zones. For ease of implementation, Standard 169 has assigned thermal zones on a county-wide basis to all the counties in the United States. In the 2013 version of Standard 169, over 300 U.S. counties are assigned to a different thermal zone than in the original version of Standard 169. The changes affect two-thirds of the states. The changes affect virtually all of the climate zones from hot to cold, but most of the changes are to counties in moderate climates. The paper provides details on the implications of these changes if the new county assignments were to simply be incorporated into Energy Standards and Codes without any adjustments to the existing building envelope requirements. [ABSTRACT FROM AUTHOR]

This paper describes a portion of a study which investigated the reduction of energy consumption in grocery stores in a hot and humid climate. The first part of the study investigated the maximum possible savings that can be obtained by implementing energy efficiency measures (EEMs) in a grocery store. The second part of the study took a step further and examined the option of combined heat and power (CHP) technologies to further reduce the energy consumption of the grocery store. In this paper, several energy efficiency measures (EEMs) for the grocery store were examined to reduce the overall energy consumption of the store. A calibrated whole-building energy simulation model was used to carry out this analysis. The EEMs were organized into four categories, which include measures for the envelope; lighting and daylighting; heating, ventilation, and air conditioning (HVAC); service hot water (SHW) systems; and refrigeration systems. Only certain measures were selected under each category depending on the simulation capabilities of the whole-building simulation program selected for the analysis. The measures were first assessed individually and then combined to provide a cumulative energy savings based on each category. Savings were assessed in terms of both site and source energy consumption. EEMs for the building envelope were found to be least effective of all the measures considered by this study. Savings for site energy consumption in this category were in the range of -0.3% to 3.1% and for source energy consumption were in the range of -0.20% to 2.3%. Savings for site energy consumption on implementing EEMs for lighting and daylighting were in the range of 4.3%to 5.4%and for source energy consumption were in the range of 7.5% to 9.7%. Savings from implementing EEMs for the HVAC systems for site energy consumption were in the range of 0.2%to 12.1% and for source energy consumption were in the range of 0.1% to 4.9%. Savings from implementing EEMs for refrigeration systems for site energy consumption were in the range of 0.1% to 16.9% and for source energy consumption were in the range of 0.1%to 9.2%. Selected measures when grouped together provided site energy savings of 57.9% and source energy savings of 55.8%. [ABSTRACT FROM AUTHOR]

This paper presents the overview of the currently practiced new housing constructions in Ontario based on a survey to local homebuilders in the Greater Toronto Area (GTA), which was conducted as part of the proposed methodology to determine the suitability of the potential optimal upgrades considered for the analysis. Also presented in this paper is the economic feasibility study of the identified optimal upgrades from the survey for the selected cities in Ontario with varying climatic conditions. Based on the results of the survey, it was concluded that the participant builders have already implemented or considered for implementation some of the advanced technologies into their current building practices to achieve the energy performance level that exceeded the minimum requirements as specified by the existing Ontario Building Code (OBC). Furthermore, the results of the economic feasibility study showed that, based on the life cycle analysis of 30 years, the combination of optimal upgrades comprised of increasing the thermal resistance of the building envelope components, and installations of the most energy-efficient heating, ventilating, and air-conditioning (HVAC) system could achieve up to 31% reduction in both the estimated total annual energy consumption and greenhouse gas (GHG) emissions in comparison to the same building configuration, but built in accordance with the OBC, and without the implementation of the identified optimal upgrades. Furthermore, with the installation of a residential photovoltaic (PV) system combined with these upgrades, the estimated total profit of up to $89,035 could be achieved through Ontario's micro Feed-in-Tariff (FIT) program, allowing a homeowner to pay for the installation of additional upgrade(s) to further improve the energy efficiency level of a home, ultimately reaching the net zero energy status. [ABSTRACT FROM AUTHOR]

Commercial buildings consume a large amount of energy -- 35% of the nation's electricity, and 13% of the nation's natural gas. And the majority of this existing commercial building stock will still exist over 20 years from now. Such a large stock of existing buildings presents a good opportunity for decreasing our national energy demand through energy retrofits. This paper will present key concepts for cost-effective retrofit projects with deep energy savings (45% and above) in existing buildings. Achieving deep savings typically requires an integrated design process, where all building systems and assemblies are evaluated in a holistic manner. With this process, for example, HVAC equipment replacement measures are evaluated in consideration of load reduction measures. The paper will present examples and considerations related to the integrated design process. The upfront cost of a deep retrofit project may be difficult to justify on the basis of energy savings alone. However, the business case is much easier to make when planned upgrades and equipment replacements are taken into account. The paper will present methods and considerations related to planning for retrofit projects, and evaluating and ranking deep retrofit options. The Department of Energy has recognized the energy savings potential in existing commercial buildings, and has recently published two Advanced Energy Retrofit Guides that target methods for achieving various levels of energy reduction in existing buildings. The guides address the office and retail building sectors. As representative examples of content included in each of the guides, the paper will include technical details from the guides related to specific energy reduction measures. The general project planning considerations presented in the guides are applicable nationwide, while the energy and cost savings estimates for recommended energy efficiency measures have been developed based on energy simulations and cost estimates tailored to five distinct climate zones. The results of these analyses are presented for individual retrofit measures, as well as a package of recommended measures for three project types: operations and maintenance measures implemented through the existing building commissioning process, standard retrofits, and deep retrofits. The paper will present these measures and packages, to show examples of retrofits that can be implemented in existing commercial buildings to achieve various levels of cost-effective energy reduction. [ABSTRACT FROM AUTHOR]

The paper deals with the integrated building design process in the French tropical island of La Reunion throughout the design of the first Net Zero Energy Building named ENERPOS. So far the design process in France is not well adapted to the design of zero energy buildings and does not allow the easy achievement of energy efficient buildings. A reorganization from the brief to the construction of the building itself is therefore necessary. Several reasons can explain this statement. First, no thermal standards are mandatory in Reunion Island as most of the French overseas territories. This leads to the construction of energy consuming buildings. However, a guideline named PERENE has been set-up but the prescriptions are not mandatory. They concern the thermal conception of buildings as well as the energy performance of buildings and are specific to each climatic zone that has been defined in PERENE. Despite that, the PERENE rules give only a minimum level of performance and can not be considered as the optimum design. Second, the lack of knowledge in the HVAC design practices about the last design tools and the lack of discussion between the people involved in the design process - i.e. the architect and the engineers is an obvious weakness for optimizing the passive design of the envelope and the systems. In some cases, the design teams selected by public owners - the Regional Council, the University and the City Councils have most of the time an overall good level of knowledge but unfortunately the brief of the building is not accurate enough in terms of objectives and energy performance requirements to meet. The paper will present the state of the art in France in terms of design process from the brief until the completion of the building. Then the adopted methodology will be introduced and applied to the case study of the ENERPOS building. The design stage has focused on the development of new methods for the design of zero net energy buildings in French tropical overseas territories. As the building has been completed in 2008, the lessons learned will be presented as well. [ABSTRACT FROM AUTHOR]

Heat pumps provide an efficient heating method; however they suffer from sever capacity and performance degradation at low ambient conditions. This has deterred market penetration in cold climates. There is a continuing effort to find an efficient air source cold climate heat pump that maintains acceptable capacity and performance at low ambient conditions. Systematic optimization techniques provide a reliable approach for the design of such systems. This paper presents a step-bystep approach for the design optimization of cold climate heat pumps. We first start by describing the optimization problem: objective function, constraints, and design space. Then we illustrate how to perform this design optimization using an open source publicly available optimization toolbox. The response of the heat pump design was evaluated using a validated component based vapor compression model. This model was treated as a black box model within the optimization framework. Optimum designs for different system configurations are presented. These optimum results were further analyzed to understand the performance tradeoff and selection criteria. The paper ends with a discussion on the use of systematic optimization for the cold climate heat pump design. [ABSTRACT FROM AUTHOR]

Buildings designed and built in cold climates, such as Canada, are typically optimized for minimizing heating energy demand, however, with climate change, these buildings may experience increased cooling energy demand and overheating risk during the summer. This paper presents the evaluation of the effect of climate change on the thermal conditions of multi-unit residential buildings that meet the current energy code and Passive House (PH) requirements under historical weather year, future horizon years and extreme warm conditions (heat wave) through simulations. A wood-frame mid-rise and a pour-in-place concrete high-rise multi unit residential building are selected as case study buildings. [ABSTRACT FROM AUTHOR]

In most climates heating and cooling systems place large demands on the electrical power grid. This paper will discuss the concept of 'Energy Farming' harvesting and storing as a method of reducing these demands and their impact on the global climate. Whilst 'Energy Farming 'is of interest as a means to reduce the required capacity from the electrical infrastructure, the discussion will extend to reducing the total installed cooling capacity and energy demand. The paper will explore the relationship between mechanical cooling and electrical demand profiles and consider the benefits of storing energy. This will include traditional methods of thermal storage such as ice storage with unconventional operational regimes. The use of 'Energy Farming 'is of particular importance in countries with expanding populations, increased energy demand and consumption. The discussion will further extend to the increased use of renewable technologies such as wind power and solar power. A climate friendly building 'Farms Energy'. [ABSTRACT FROM AUTHOR]

The paper summarizes the results of a series of analyses to assess the impact of the selection procedure used to generate of typical year weather on annual building energy use. The building energy analysis is carried out using detailed whole building simulation tool that utilizes hourly typical year weather files. Annual energy use for prototypical office buildings are obtained for 10 sites representing a wide range of climatic conditions in the U.S. In particular, the analyses presented in this paper evaluate the impacts of weighting factors for various weather variables and of the length of historical data used on predicting the energy use of building systems. The results of the analysis indicated that a maximum of 5% difference in annual office building energy use can result from the selection procedure used to generate typical weather year for the 10 US climates considered in this study. [ABSTRACT FROM AUTHOR]

Energy efficiency has become increasingly important in the data center industry, driven by rising energy prices, environmental legislation, corporate social responsibility pressures, and competition. Energy efficiency is part of sustainability, however, consideration of other aspects such as the embodied environmental impact of materials, components, and systems is needed for a holistic view. Life-cycle assessment (LCA) is a useful methodology that examines wider environmental impact including areas of protection such as climate change, ecosystem quality, human health, and resource depletion. The industry is starting to become more aware of these issues and is developing metrics to quantify performance. This paper describes key data center sustainability issues identified by the life-cycle assessment of data centers and proposes how the industry could approach its environmental responsibilities in order to capitalize on the business opportunity as well as demonstrating sustainable leadership. [ABSTRACT FROM AUTHOR]

Today designers, as a result of climate change concerns, are being asked to consider new lower Global Warming Potential (GWP) unsaturated hydrofluorocarbon (HFO) refrigerants and blends of hydrofluorocarbon (HFC) with HFO refrigerants, some of which are slightly flammable under certain conditions, as well as the less than desirable natural refrigerants. In the lower GWP refrigerant future, the world will adopt refrigerants with less than optimal properties in some applications. A single refrigerant, such as R-22 or R-410A that addresses a large area of market demands for a safe, high efficiency refrigerant with lowest cost products may not be available. In general, product designs may have to compromise on efficiency, safety and reliability which could lead to increased product costs for consumers and may result market fragmentation by refrigerant type to enable this future. In some instances, new HFO refrigerants will be able to maintain society's demands for efficiency, safety and reliability while balancing the need for lower direct GWP impact. In other instances, acceptance of significant product and application design compromises, such as the use of flammable refrigerants, will be required or more costly solutions will need to be considered because of safety, efficiency, capacity or reliability constraints. Natural refrigerants will gain more attention and expanded use when efficiency, safety and reliability can be delivered at a reasonable cost to consumers. Some natural refrigerants being considered and adopted today will be phased out because of ever increasing efficiency needs. This paper will review the various low GWP refrigerant options being proposed and weigh the compromises they present for their future adoption. [ABSTRACT FROM AUTHOR]

Residential ground source heat pump systems in heating-dominated climates often incorporate auxiliary electric resistance heating. This is often utilized for some portion of the winter heating -- it could be intended only for rare, emergency use, or it could be intended to provide a significant fraction of the annual winter heating. In Sweden, where a typical ground source heat pump provides both heating via radiant panels and domestic hot water, the auxiliary electric resistance heating may be activated either when there are high domestic hot water loads or when ground heat exchanger temperatures fall to low values. In cases where the electric resistance heating provides a significant fraction of the annual winter heating, several advantages are gained: a smaller and less expensive heat pump is required; a smaller and less expensive ground heat exchanger is required. But this comes at the expense of a lower system seasonal coefficient of performance and higher operation costs due to increased electricity usage. This paper evaluates the tradeoffs between higher reliance on auxiliary electric resistance heating (with corresponding lower investment cost) and lower reliance on auxiliary electric resistance heating (with corresponding lower operating cost) for a typical Swedish house - a renovated 1940s-era house in Stockholm. The hourly building heating loads and water heating loads are estimated with a building simulation program. A range of system designs are developed with different heat pump capacities and different ground heat exchanger sizes. The different systems are simulated to compare operation and actual electricity consumption. The simulation evaluates the performance of the ground heat exchanger, heat pump, and auxiliary electric resistance heating for a ten-year period, the 5th year taken as typical. First costs and operating costs are determined based on current costs in Sweden for ground source heat pump systems and electricity. The optimal design is determined and a range of near-optimal designs are considered. [ABSTRACT FROM AUTHOR]

This paper announces the completion of a large new data set of International Weather for Energy Calculations 2 (IWEC2), i.e., typical year, weather files for 3012 locations outside of the U.S. and Canada and describes the procedures used to produce these weather files, including how the raw weather data from the Integrated Surface Hourly (ISH) database were processed and how missing records and unrecorded climate parameters have been derived. Particular attention was paid to the derivation of global horizontal and direct normal solar radiation using a combination of empirical and analytical solar models. The procedure used to select the typical months making up the IWEC2 files from the historical weather record. is also explained. These IWEC2 weather files are then compared to other sources of international weather data and to an earlier, smaller set of IWEC weather files developed in 2001. The IWEC2 weather files are found to have very similar heating degree days, and slightly more cooling degree-days than the IWEC. There is substantially more variation in the solar radiation, with the IWEC2 weather files having somewhat less total and somewhat more direct normal solar radiation than the earlier IWEC weather files. [ABSTRACT FROM AUTHOR]

The influence of increasing oil prices, the effects of climate change, and the desire to become independent of fossil fuel imports have stimulated many countries and their communities to set ambitious goals to reduce energy use and to increase the relative amount of energy derived from renewable energy sources. The most ambitious goal is to become net-zero relative to fossil fuels or to employ the concept of the energy neutral community/campus. Essentially, both terms denote an energy configuration in which the amount of fossil fuel-based energy used over the course of a year is equal to the amount of energy derived from renewable energy sources that is exported from the community/campus to a power or thermal grid for external users' consumption. Under ideal circumstances, the community consumes no fossil fuel-based energy, only energy generated from renewable sources; this would require the availability of long-term thermal and power storage systems. The achievement of such energy goals in economical and physically realistic ways would require new, unconventional approaches with respect to organization, implementation, funding, and technical decisions. The technical approach involves the emphasis on energy conservation, implementation of energy efficiency measures, use of waste energy streams, reduction of fossil fuel-based energy (if needed), and/or complementation or replacement of fossil fuel-based energy with energy derived from renewable sources. This paper explores approaches used by some of the most innovative International Energy Agency (IEA) countries to develop an ideal road map and transition process to reach net-zero or near net-zero energy targets; analyzes best practices in different countries to provide the best examples of net-zero applications across the globe; and, based on an analysis of solutions using front-running methods and technologies, makes recommendations for energy master planning towards net-zero communities and campuses. [ABSTRACT FROM AUTHOR]

With utility costs projected to increase in the near future, many developers and planners are beginning to view energy conservation measures more seriously. Energy modelers are going to be consulted more frequently in order to determine the feasibility of implementing these measures into future projects. However, before justified decisions can be made regarding incorporating energy conservation measures, a determination must be made on how accurate current energy modeling predications are based on actual measured data. This paper will address a study performed on four facilities comparing projected energy use versus measured data. The facilities encompass a wide range of building type, HVAC systems, climate regions, and operation schedules. The data provided will assist developers and planners with understanding the benefits of energy modeling and offer ideas to help further reduce discrepancies between modeled and metered data. [ABSTRACT FROM AUTHOR]

Current architectural trends as well as advanced building information modeling (BIM) software facilitate the design and construction of building forms that go far beyond the typical shoebox models commonly used for energy simulation. ASHRAE 90.1 Appendix G provides two-dimensional guidelines for how to model thermal zones in buildings where HVAC systems and zones have not yet been designed. What is the best way to zone unusual three-dimensional shapes that present issues beyond what is covered in the ASHRAE guidelines? This paper will examine this question and determine the impact on energy model outputs by studying 3 different unusually shaped buildings of 2 different building use types in 4 different climate zones. Several zoning approaches beyond the ASHRAE guidelines will be simulated and compared using DOE-2 simulation engine and TMY2 climate data. [ABSTRACT FROM AUTHOR]

The U.S. Army Corps of Engineers, in collaboration with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL), academia, and private sector subject matter experts, recently completed an energy study to evaluate potential site and source energy-use reduction in new Army buildings. The study was completed in response to the mandates for energy savings in federal buildings enacted by the U.S. Energy Independence and Security Act of 2007 (U.S. Congress 2007). The building types studied included an Unaccompanied Enlisted Personnel Housing (UEPH or barracks), a brigade headquarters (administrative building), a company operation facility, a maintenance facility, and a dining facility (DFAC). The study was conducted for representative locations in all 15 DOE identified climate zones in the United States with building designs adapted to these climatic conditions. This paper presents the results of the energy analysis for a typical Army dining facility. It discusses energy efficiency measures and combinations used to reduce both internal and external loads on the building and overall energy use. The largest load in a DFAC is the cooking, and the currently available best-in-class kitchen equipment is included in the final design. The potential site energy savings compared to the energy code range from 21% to 38%. The potential source energy savings compared to Commercial Building Energy Consumption Survey ranges from 37% to 42%. Additional savings may be obtained if an efficient cogeneration system is used and the building is considered as a part of the building cluster or community to fully utilize the energy from the cogeneration system. [ABSTRACT FROM AUTHOR]

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. Laboratory results demonstrate the efficiency of this technology under most of the conditions tested and show that differences in control schemes and design features impact the performance of the individual units. These results were used to understand current model limitations, and then to bracket the energy savings potential for HPWH technology in various US climate regions. Simulation results show that HPWHs are expected to provide significant energy savings in many climate zones when compared to other types of water heaters (up to 64%, including impact on HVAC systems). [ABSTRACT FROM AUTHOR]

This paper will examine the challenges for energy-efficient ventilation that shopping malls present. In these buildings, the retail stores are often heated, cooled and ventilated separately from the mall central spaces, yet are connected to them by large, open doorways through which natural air exchanges occur, hence inextricably linking the two spaces. However, the central spaces of the mall are usually deemed to have the potential for more relaxed ranges of interior conditions than the retail stores adjacent to them, and regulatory requirements for these two types of space can also differ. The façade and roof access to the central spaces of malls mean that they have the potential to be ventilated naturally, or with a hybrid ventilation scheme. The extent to which this is beneficial depends on the local climate, as well as aspects of mall design such as glazing extents, and potential for low-level and high-level ventilation openings. This study examines potential strategies for reducing energy use in such buildings by means of natural and/or hybrid ventilation of the mall central spaces. These strategies need to be formulated with the aim of reducing the whole building energy consumption, taking into account both the heating and cooling demands for the central space, and those of the adjacent retail stores interacting fluid mechanically with it. A numerical thermodynamic model has been developed to investigate this with respect to energy consumption and internal comfort of a hypothetical mall under various ventilation strategies. The influence of ventilation strategy on cost of plant (capital and maintenance) will also be discussed. [ABSTRACT FROM AUTHOR]

Northern climate like the one in Montreal 4,557 DD (SI) - (8,200 DD (IMP)) presents huge challenges to the designers to reach Net-Zero Energy buildings. A large amount of the energy required is related to the heating of the outside air and the 24 hours/day, 7 days/week operation. It is not rare to be faced with labs designed a few decades ago which consumes in the order of 2150 kW-h equiv /m²-year (200 kW-h equiv/sq.ft.-year), compared to 540 kW-h equiv / m²-year (50 kW-h equiv / sq.ft.-year) and better for recent labs. This paper presents a list of potential options to improve energy efficiency. Three laboratories are presented with the different measures that were applied in those buildings. [ABSTRACT FROM AUTHOR]

Attic Radiant Barriers (RBs) are proven technologies that significantly reduce the flow of radiant heat across attic spaces. This decreases the heat flow across the ceilings of buildings, which in turn lowers space cooling and heating loads, and produces energy and cost savings. This paper provides a general description of RBs, including installation configurations, the physical principles that make them work, and the laboratory and field experiments used to evaluate their thermal performance. An extensive review of the literature is summarized, highlighting fundamental issues, such as reduced ceiling heat flows, reduced space cooling and heating loads, and changes in attic temperatures produced by the installation of RBs in residential attics. Causes that affect RB performance, such as the influence of attic insulation level and climate, are presented. The data indicate that, on average, RBs reduce summer ceiling heat flows by 23 to 45% depending on the insulation level, whereas winter ceiling heat flow reductions are about 40% of the summer values for the same insulation levels. The data also indicate that RBs reduce space cooling loads by 6 to 20% and that space heating loads reductions are also about 40% of the space cooling load values for the same insulation levels. [ABSTRACT FROM AUTHOR]

The definition of a good indoor climate is important to the success of a passenger rail coach, not only because it will decide its energy consumption and thus influence its sustainability but also because good comfort for long journeys is essential. The intention is to use the results to optimize the control of the ventilation system to provide an indoor climate that passengers will find comfortable. The results of this study show how passengers' thermal comfort was affected by changing the supplied air conditions. This paper primary discusses and analyzes the simulation of the air flow and thermal patterns in a Subway station. Numerical simulation of a typical model is presented. Modifications were applied to the numerical model to show the improvement of the thermal comfort level. The pre-processor Gambit is used to create the geometric model with parametric features. Commercially available simulation software "Fluent 6.3" is incorporated to solve conservation of mass, momentum and energy in the processing of air distribution, and to analyze turbulence affection combined heat transfer on air distribution. In this thesis work, the socalled standard k-ε turbulence model, one of the most widespread turbulence models for industrial applications, was utilized. Basic parameters included in this work are air temperature, air velocity, relative humidity and turbulence parameters are used for numerical prediction of indoor air distribution. Measurements of air velocity, and temperature were undertaken in a plane perpindicular to the supply diffuser. These values were then compared to the obtained results from the simulated cases. The thermal comfort prediction through this work was based on the PMV (Predicted Mean Vote) model and the PPD (Percentage Predicted Dissatisfied) model, the PMV and PPD were estimated using Fanger's model. [ABSTRACT FROM AUTHOR]

Modeling of energy use in existing buildings is required for different applications such as building energy management, establishing baselines, and calculating retrofit savings. A single or multivariate regression model is mostly used as a means of developing these models of energy consumption in buildings. This paper explores the applications of single and multivariate models on estimation of monthly energy consumptions in schools and discusses the several aspects of model improvements. Several regression models ranging from a simple only outdoor dry-bulb temperature to multivariate models are studied to find a comprehensive methodology in estimating energy consumptions in schools located in hot and humid climates. Data on energy consumptions in 225 schools selected from four different counties in central Florida are collected to evaluate the models and provide recommendations for improvements. The results show that by including the school scheduling in the model, the accuracy in the monthly energy consumption prediction is significantly improved comparing to that when using only temperature regression model. [ABSTRACT FROM AUTHOR]

Analysis of nonresidential building structures shows that many are characterized by high energy consumption. Administrative/office buildings and production and maintenance facilities pose specific challenges to those seeking improved energy management and building energy performance. Questions of energy consumption in these buildings are generally seen as secondary to the improvement of comfort and/or functionality. This is most pronounced within the existing building stock. Decisions to retrofit a building are often made because of dissatisfaction concerning the comfort level or as a consequence of changes in building use or in processes performed in the building. The primary goal of the retrofit is to improve these conditions. Good technologies to meet this end are currently available. The objectives of the International Energy Agency Energy Conservation in Buildings and Community Systems (ECBCS) Programme Annex 46 (IEA 2011a) is intended to provide tools and guidelines to identify energy conservation opportunities in buildings and to improve the indoor environment of these buildings in energy-efficient retrofitting projects. Among the tools developed by this project is the Energy and Process Assessment Protocol, which provides an energy assessment methodology and procedure suitable for different types of sites, including a variety of different nonindustrial buildings with energy requirements dominated by climate, and industrial buildings with high energy loads dominated by internal processes and high ventilation requirements per floor space. This paper presents the energy assessment methodology for a single building or a large building stock, along with examples of typical energy wastes and inefficiencies in different types of buildings and typical processes. [ABSTRACT FROM AUTHOR]

Our paper presents findings from in-depth monitoring of two single-family "Net Zero Energy Homes" (NZEH) in Massachusetts, begun in July and October 2010 respectively. It concentrates on the cooling period 2010. In both buildings, we measured the electric energy consumption at the circuit level. In addition, we measured parameters related to indoor comfort and indoor air quality on seasonal test series. Based on these measurements, we generated average daily electric load profiles during a large portion of the cooling season. We also used indoor temperature and relative humidity measurement to evaluate thermal comfort based on static and an adaptive comfort models. Finally, we used CO2 concentration measurements as an indicator for indoor air quality (IAQ) and to assess the sufficiency of air exchange rates. [ABSTRACT FROM AUTHOR]

The new refrigerant HFO-1234yf is being evaluated for use as a replacement for R-134a in many cooling applications. It has been proposed to use HFO-1234yf for many AC and refrigeration applications, but we show that it is not a direct replacement for higher performance refrigerants like R-410A for heating and cooling. New refrigerant compositions have been developed and are being evaluated for use in air conditioning and heat pump applications in order to reduce emissions of carbon dioxide and higher GWP gases that can contribute to global climate change. Some of these new compositions are marginally flammable, and are expected be classified by ASHRAE and ISO as "2L" refrigerants based on low burning velocity and low heats of combustion. This paper presents measured cooling and heating performance results for some of the new candidate refrigerants, and environmental impacts are modeled based on those measured results.. Some of the trade offs impacting environmental impact of the developmental refrigerants, including GWP value and energy efficiency performance will be discussed. It is shown the lower GWP fluids do not necessarily give the best environmental performance. [ABSTRACT FROM AUTHOR]

To help mitigate climate change, the incremental approach to making homes and buildings "less bad' or 30% better than code is not going to work. We need aggressive, actionable solutions now. The Passive House standard (Passivhaus in German) is one of the world's most aggressive, proven, voluntary approaches to radical energy reduction, assured indoor air quality, durability, and thermal comfort in the world today. The Passive House standard has roots in Sweden, Germany, Canada and the US. While much of the approach to good, low-energy and passive design is well known, it is still seldom practiced. This paper will introduce and explore the Passive House standard design approach and requirements as well as demonstrate its application to new and retrofit projects in the North American context. Drawing from expertise on the early Passive House projects in the US and Germany, as well as on the ground experience of more recent successful and unsuccessful Passive House projects in North America, a journey toward the best practices in design application, cost and certification will be discussed. A brief review of the various products and systems incorporated in North American projects to meet the aggressive requirements of the passive house standard will also be introduced. [ABSTRACT FROM AUTHOR]

Much work has been done in the last decade on the determination of exterior loading conditions including rainfall. These methods are generally geared for heat, air, and moisture (HAM) modeling and involve selecting a "reference year". Whereas the real climate of the reference year can be followed in simulations, the loading has to be simplified in an experiment. To set deterministic or quasi-stochastic loads for experimental testing, the climatic variables can be statistically analyzed. However, the reference year does not provide information in terms of wind-driven rain infiltration loading. As well, since in an experiment the water must be inserted physically, two more steps are required to determine the load conditions: the water insertion rate must be established as well as the method of water introduction. This paper presents various existing methods for selecting a climate-representative reference year and their limited applicability for experimental testing. Methods to determine the impinging wind-driven rain on building facades are discussed, as well as previous work on wind-driven rain infiltration and methods used for the experimental simulation of wind-driven rain infiltration. The findings from the literature review show that there is a need for the development of a methodology to simulate wind-driven rain infiltration that takes into consideration climatic variables, such as rainfall and wind speed, as well as building geometry, location on a facade, and an estimate of wind-driven rain infiltration rates in the context of building envelope testing. [ABSTRACT FROM AUTHOR]

The European building industry has for years utilized autoclaved aerated concrete (AAC), especially in Germany and Poland. However, AAC shows considerable decrease of thermal resistance with increasing moisture content. The main objective of this paper is to quantify the effect of initial moisture on the hygrothermal and energy performance of AAC used in a residential house located in Warsaw, Poland. Annual profiles of moisture content in a 36.5 cm cellular concrete wall were derived for Polish climatic conditions using a state-of-art model of coupled heat, air, and moisture transfer in porous building materials. Possible variations of the hygrothermal performance and differences in kinetics of drying of the wall exposed to the typical and real weather conditions for a specific year were estimated. Moisture distribution changes in the ACC wall were also calculated for three years of exposure in Poland's typical climatic conditions. Space- and time-averaged values of moisture content, thermal conductivity, apparent density, and specific heat of cellular concrete layer were calculated for each month of the analyzed period. These averaged material properties were used in DOE-2.1E simulations of the whole building energy performance of a 286 m2 (3,079 ft2) residential house for each month of the analyzed period. Moreover, monthly values of energy released or absorbed on the internal surface of the wall, due to the condensation or evaporation of moisture, were calculated and used to approximate the total effect of initial moisture drying on energy performance of the whole building. [ABSTRACT FROM AUTHOR]

The life-cycle assessment (LCA) methodology is used in this paper to assess the environmental effects of air-handling units (AIIU) over a 20-year life cycle. This assessment is based on quantifying the consumption of resources (energy and materials,), the harmful emissions into the environment (`air; water, and soil), and the potential changes in the environment (climate change, acidification, and ozone production,). A normal AIIU, with a face velocity of 3 m/s (600 fpm), and a small AIIU, with a face velocity of 4 m/s (800 fpm), are investigated with and without two types of air-to-air energy exchangers (plate and rotating wheel). The research demonstrates the following benefits of air-to-air energy exchangers: reduced energy consumption, reduced emissions to the environment, and reduced potential harmful changes in the environment. For both of the AIIUs' studied, these benefits are several times greater than the burdens arising from the production and operation of the AIIU, where the function of the AIIU is to provide 2000 L/s (4200 cfm) of outdoor air to the building space for 2500 h/year, but not to condition this air A larger AIIU with an air-to-air energy exchanger of higher efficiency has the smallest harmful effect on the environment. [ABSTRACT FROM AUTHOR]

Single-value ratings for heat pumps and air conditioners have become industry standards and are widely used by consumers, designers, and program managers for equipment selection and prediction of performance. On the heating side, the standard rating is the heating seasonal performance factor (HSPF), and on the cooling side the standard rating is the seasonal equipment efficiency ratio (SEER). These values are determined under set conditions. However, the actual performance of the equipment depends on the climate in which it is being used. Furthermore, the overall energy use can be greatly impacted by factors such as control strategy and duct losses. This paper presents the results of computer modeling using the bin method to estimate the impact of climate, certain common control strategies, sizing approaches, and duct losses on the HSPF of heat pumps in two climates in the northwest United States. Comparisons with field data and observations show impacts on heat pump performance consistent with modeling results. [ABSTRACT FROM AUTHOR]