Building Energy Simulation

In this analysis, we considered three building types that offer the most savings potential: residences, offices, and retail stores. Each building type was characterized in detail by Pre-1980 (old) or 1980 + (new) construction vintage and with natural gas or electricity as heating ...

This study directs attention towards the New Cairo community, which is one of the new urban settlements that have been developed around Cairo, Egypt. People recently have tended to install or extend mechanical cooling equipment in their dwellings in order to overcome the problem of thermal discomfort from overheating. Although the mechanical cooling significantly raises utilities bills, it is still the preferred choice for the majority of the residents. The lack of awareness about the advantages of Passive Cooling Techniques (PCT), in addition to uncertain about their costs and effectiveness, has made PCT unpopular options for both designers and owners. This study investigates the costs and benefits of two PCT, which include the influence of the thermal transmittance of the walls (U-value), and the attachment of solar shading devices. The Whole Life Cycle Costing (WLCC) evaluation method is used to estimate the payback period of applying the PCT. The PCT were simulated using the dyn...

Building geometry, urban morphology and local climate are crucial aspects to optimize the energy performance of buildings at neighborhoods scale. In addition, urban form is a key parameter in modifying solar availability in densely built-up areas. This paper explores relationships between urban form and energy performance with implications for solar energy production on building roofs. This study investigated six neighborhoods of Turin (Italy) analyzing the urban morphology and the solar potential, taking into account the urban block typologies found across the city. From the energy simulations-made with the use of an urban-scale energy model-it has been found that in densely urban context, the optimal shape of the building-with low energy consumption and high solar energy production-must have a surface-to-volume ratio that varies between 0.37 m 2 /m 3 for favorable orientated buildings and 0.35 m 2 /m 3 for unfavorable oriented ones. These results could help in the design phase of new neighborhoods or in the reuse of existing buildings and empty spaces to promote the transition to low-carbon energy.

This paper outlines the conceptual development of a building energy simulation model for the Single Coil, Twin Fan Air Conditioning (SCTF) system in the whole building simulation program EnergyPlus. The SCTF system is a unitary, multi-zone system which conditions the outdoor ventilation and recirculated return air in two separate streams through a single compartmented cooling coil and supplies these unmixed streams via two variable speed fans and a dual duct arrangement to zonal mixing boxes. The main challenges addressed in EnergyPlus include the existing inability to concurrently simulate unmixed air streams within a centralized VAV system, supply and control outdoor air and recirculated air independently to a space via dual duct network, and prediction of performance of a compartmented cooling coil – all of which have potential applications in other innovative systems.

This paper provides an overview of the results of a project that explores strategies for improving the thermal performance of the New South Wales Demountable Classroom in the diverse climates that occur across New South Wales, Australia. The climates in NSW vary between cool or mild temperate climates, sub tropical climates and hot dry desert climates. The demountable classroom is expected to provide comfortable teaching spaces in any of these climates. The NSW Demountable Classroom was designed 50 years ago and accounts for 12% of all government classrooms across the state. The thermal performance of existing classrooms is poor. The project uses a design led methodology to develop strategies that can be implemented by community groups to improve the performance of individual classrooms in particular locations. The strategies are evaluated using a computer simulation model. Predicted thermal comfort and annual energy consumption are used as the benchmarks for performance. The results illustrate that there are multiple strategies and combinations of strategies for improving the thermal performance of lightweight buildings in all of the diverse climates of NSW and Australia. The results also demonstrate that some of the orthodox conventions of bio-climatic design need more thorough interrogation.

The paper is focused on the dynamic simulation of a Photovoltaic/Thermal collector (PVT) integrated in a high-temperature Solar Heating and Cooling (SHC) system. The system is based on the following main components: concentrating parabolic PVT (photovoltaic thermal) collectors, a double-stage LiBr-H2O absorption chiller, storage tanks, auxiliary heaters, balance of plant devices. The PVT is made-up by a parabolic dish concentrator and a triple-junction receiver. The polygeneration system provides electricity, space heating and cooling and domestic hot water for a given building, whose simulation is also included in the model. In particular, PVT produces electric energy, which is in part consumed by the building loads (lights and equipments), in part by the system parasitic loads, whereas the eventual excess is sold to the public grid. Simultaneously, the PVT provides the heat required to drive the absorption chiller. The system was simulated by means of a zero-dimensional transient model, that allows the evaluation of temperature profiles and also heat/electrical energy flows for whatever period of the year. It is also possible to evaluate the overall energetic and economic performance on whatever time basis (day, week, month, year, etc.). The economic results show that the system under investigation can be profitable, if a proper funding policy is available. The paper also includes an extensive parametric analysis aiming at evaluating the set of design and operating parameters (solar field area, tank volumes, set point temperatures, etc.) that maximize the energetic and/or economic performance of the system.

This paper focuses on the temperature control in a multi-zone building. The lumped heat transfer model based on thermal resistance and capacitance is used to analyze the system dynamics and control strategy. The resulting thermal network, including the zones, walls, and ambient environment, may be represented as an undirected graph. The thermal capacitances are the nodes in the graph, connected by thermal resistances as links. We assume the temperature measurements and temperature control elements (heating and cooling) are collocated. We show that the resulting input/output system is strictly passive, and any passive output feedback controller may be used to improve the transient and steady state performance without affecting the closed loop stability. The storage functions associated with passive systems may be used to construct a Lyapunov function, to demonstrate closed loop stability and motivates the construction of an adaptive feedforward control. A four-room example is included to illustrate the performance of the proposed passivity based control strategy.

Dynamic simulation is widely used for assessing thermal comfort in dwellings. Simulation tools, though, have shortcomings due to false assumptions made during the design phase of buildings, limited information on the building's envelope and installations and misunderstandings over the role of the occupant's behaviour. This paper presents the results of a Monte Carlo sensitivity analysis on the factors that affect the PMV comfort index. The reference building was simulated as both Class-A and F according to the Dutch determination method for the energy performance of residential functions and buildings (ISSO 82.3, 2009), with three different heating systems. The study focuses on the heating period which is of main interest concerning residential energy use in the Netherlands. For the PMV the most influential parameters were found to be metabolic activity and clothing, while the thermostat had secondary impact.

For thousands of years people have been creating models to translate and improve their ideas into three dimensional reality. Model making is a logical next step in the thinking process for many ideas. Once someone starts using materials and fabrication techniques they are able to refine their ideas to make them work. Those in the model making profession through experience and talent have advanced skills with fabrication techniques and their knowledge of what materials would work best. To design; one must possess a wide imagination, and also to design one must be an expert in all the basic criteria for the design principles. To design; one must also have extensive knowledge of the characteristics and quality of materials used in construction. All of these principles and necessities can be dealt with one main topic that covers all the mentioned issues “Understanding/ incorporating the modeling Techniques” throughout the design process for both architects, designers and students who, indeed trying to comprehend the value of real architecture. Shortly; this study examines the model making as a value added design in several terms. Firstly, in art; how the entire design is seen and sensed as a one piece of artwork prior to the construction stage. Then, design efficiency; What is the role played by the modeling process in terms of methods of construction, that is, does it convinces and confirms the design efficiency!. And also in the context of Architectural design; that is, how and why model making is considered as a major step in the design process and how it enriches the designers imagination and creativity and what can the model making add to the design or the designer himself in the context of productivity.

Building performance is a function of a number of variables each of which is important to analyse concurrently when conducting a POE study. The development of framework for assessing buildings is significant as it will provide an evaluation tool for ensuring sustainable buildings. This study developed an index for evaluating the overall performance of office buildings in Nigeria. A Total of 51 professionals in the built environment were surveyed. The data obtained were analysed using content analysis technique, pair wise comparison (one sample t-test) and regression analysis. The results showed that; the performance criteria which are pertinent to the performance of office building in order of their importance were building integrity (54.54), indoor air quality (53.69), safety and security (64.04), thermal (46.77), spatial (7.27%), visual (44.01), spatial (43.33) and acoustic performance (43.62); priority placed by individual professional, architects rated safety and security and building integrity (18) most important and acoustic least (9) important, builders rated IAQ and visual performance (20) most important and building integrity (8) least important, estate surveyors ranked safety (21) and building integrity (17) performance most important and acoustic performance (7) least important, mechanical engineers rated safety (22) and building integrity (0) Original Research Article

Simulations are commonly used to assess building performance with respect to energy demand and indoor environment. However, the use of performance simulations is limited during the early stages characterized by large uncertainties. This industrial Ph.D. study presents a novel  simulation approach that relies on thousands of simulations representing the multidimensional design space. Interactive visualizations enable decision-makers to explore, in real-time, the vast design space and identify favorable solutions which satisfy the needs of different stakeholders. Sensitivity analysis helps reveal important
design parameters that require the most attention when seeking to improve building performance. Fast metamodels facilitate immediate feedback on design changes and reduce time-consumption related to performance assessment. Ultimately, the work described in this thesis and on buildingdesign.moe.dk facilitates proactive guidance and supports collaboration between building owners, architects, engineers, and contractors. This helps the design team to create buildings with high performance and minimum costs.

This paper proposes a new demand-side management (DSM) scheme for the autonomous DC microgrid for the future building. The DC distribution system is considered as a prospective system due to the increase of DC loads and DC power sources such as photovoltaic (PV), and battery bank (BB). The BB responds to the changes in a power imbalance between PV generation and demand within an autonomous DC microgrid. The power loss during charg-ing/discharging of the battery is the great challenge for the autonomous DC microgrid supplied by PV. It decreases the system efficiency. The control objective of the proposed DSM scheme is to use the PV energy more efficiently. The proposed control algorithm shifts the deferrable load from non-sunny hours to sunny hours and decreases the building demand during non-sunny hours. In this way it decreases the charging/discharging cycles of the batteries. This is reducing the power losses in the battery and improves system efficiency. The proposed scheme reduces the size of the PV plant, storage and capital cost of the system. The results showing a clear shifting of the load so that to get significant reduction in the system cost which is given numerically as percentatge saving.

Sustainable construction nowadays requires the use of environmental friendly materials with high rate of insulation. Straw construction presents some advantages such as renewability with low energy input, recyclability, CO2 storage, and local availability that implies short distribution cycle. However, before the introduction in the construction industry, attention needs to be paid to the construction technology using such natural materials. In this paper there were developed elements of enclosing structures for two technologies of straw frame building; was done thermal modeling of potentially weak assembles of building envelope; were calculated R-values and then compared with normative indexes; was evaluated efficiency of usability two technologies of low-raise building in cold and wet conditions of St. Petersburg.

Today’s residential construction industry is capable of producing exceptionally high performing houses that far exceed compliance with local building codes.  We feel that setting a target of Net-Zero Energy (NZE) is feasible in the US considering the design and construction technology available. 

This paper is part of an extensive project focusing on residential construction utilizing Passivhaus strategies with an emphasis on solar design and a target of Net-Zero energy use.  The focus of this paper is on the role of simulation as a design aid in developing guidelines relating to building form, orientation, glazing, and roof area for solar electrical and thermal systems.

Purpose – This paper aims to optimise building orientation in Tehran, as well as determining the
impact of its shape, relative compactness (RC) and glazing percentage on its optimised orientation.
Design/methodology/approach – A cubic module was used and a set of 8 of the same module with
16 different formations were analysed for their orientation (360°), the RC (four groups) and the amount
of glazing percentage (25, 50 and 75 per cent).
Findings – The results show that the optimised orientation of a building in Tehran strongly depends
on its passive solar heat gain elements, their orientation and their position in building; furthermore,
glazing percentage amount, amongst the studied factors, plays the most important role in determining
a building’s orientation.
Practical implications – The application of the findings of this study in Tehran city planning and
also technical details of buildings will lead to a great energy saving in construction sector. Furthermore,
the deployment of the proposed design guidelines in construction has explicitly been proven to save a
prodigious amount of energy.
Originality/value – The main research question is taken directly from authors’ initiative when
working as university professor and research associate. The case study buildings, their morphological
configurations and sustainable features have not been presented before in an academic journal.
Keywords: Solar energy, Correlation analysis, Simulation, Optimisation, Regression, Orientation,
Energy efficient architecture, Glazing percentage, Shape

The goal of this chapter is to provide an overview of the current understanding of the concepts of Zero Energy Building (ZEB) and Nearly Zero Energy Building (nZEB). The chapter discusses the current definitions of these concepts as well their design and assessment methodologies. The chapter is based on a literature review of national action plans as well as international policies and standards. While a broad global overview of the concepts of ZEB and nZEB is targeted, a significant portion of this chapter deals specifically with documents produced in Europe where the challenges about the goals set by the Energy Performance of Building Directive (EPBD) recast are leading to discuss topics such as the energy balance methodologies, boundaries of ZEB and nZEB, type and energy sources to consider, homogenization techniques for different energy carriers and energy balance indicators. This chapter shows that an agreement towards common definitions of ZEB and nZEB is progressive, but differences among the several interpretations given worldwide still exist.

Windows are often pointed to as the weakest elements in building facades, given their low thermal resistance. Consequently, they are
a main focus during building retrofits, when their substitution is often considered an expensive but necessary choice. This article
describes a new high-performance glazing coating, which can be used for the in situ retrofit of existing windows. The easy
application of this new liquid-applied coating on the internal side of the glazing makes it possible to reduce the solar heat gain
coefficient of an existing window substantially and quickly, without interrupting the building occupancy. Experimental
characterizations of light transmittance and thermal characteristics are presented in this article. Although the new coating allowed a
reduction in the visible transmittance (VT) of only 0.1 compared to nontreated insulating glass units (IGUs), it proved to reduce
significantly the solar heat gain coefficient (SHGC) of the investigated IGUs to values below 0.45. This article also reports the results
of aging studies aiming at assessing the risks of long-term performance reductions of this new liquid-applied coating. Finally, the
results of energy simulations investigating the energy-efficiency improvements when this coating is applied to different kinds of
windows in Canada are reported.

Climate change and rising energy costs necessitate a shift in how buildings that efficiently provide comfort are envisioned. With initiatives now aiming at bringing energy simulation into the mainstream of environmental design, the applicability of state-ofthe- art simulations in formally non-constrained creative production needs to be re-evaluated. To this end, a teaching experiment that includes multidomain simulations as drivers into the early architectural design process has been conducted; Master of Architecture students create a community centre with low energy use and high daylight utilization, presented in case studies. Performance increases are achieved by making appropriate morphological choices only; form and energy are thus linked in a tectonic fashion. A novel designsimulation process model that acknowledges both creative and analytic thinking is derived and discussed in the context of on-going integration attempts.

The objective of the thesis is the development of socially, economically and environmentally viable proposals that will improve the thermal performance of the NSW Demountable Classroom and the thermal comfort of the people and communities who use them in any of the climates across the state.
The problem is significant because around 6000, or 12%, of all government classrooms in the state are Demountable Classrooms. The NSW Demountable Classroom was designed 50 years ago and was intended to, and continues to, provide the NSW government with a system of physical infrastructure that allows schools to expand and contract in response to population fluctuation as well as providing emergency accommodation at times of need in any of the diverse climates across NSW. However, they are commonly regarded as offering inferior “temporary” teaching spaces due, in particular, to the perception of their internal environmental quality.
The thesis understands buildings, including the NSW Demountable Classroom, as intrinsically complex systems that exist within other complex environmental, social and economic systems. This thesis adopts a design led research methodology that is integrative; which accepts implicitly that there is no single optimal answer or solution for a problem consisting of so many indeterminate and interrelated variables.
The thesis develops an overall strategy, and specific “Solution Sets”, for improving the thermal performance of the NSW Demountable Classrooms and the thermal comfort of those who use them
The thesis concludes that the NSW Government, in collaboration with local communities, can employ simple strategies, identified in this thesis, to create high performance, adaptable and low carbon classroom buildings at a low cost in all NSW climates. The analysis argues that the benefits of this refurbishment can go beyond comfort and engage in social and pedagogical issues.