Building performance evaluation: a dutch perspective in thermal comfort and energy consumption

Tese de mestrado integrado, Engenharia da Energia e do Ambiente, Universidade de Lisboa, Faculdade de Ciências, 2017Published works have shown that buildings often consume more energy, than is necessary for occupant comfort. The building sector is accountable for 40% of EU’s final energy use and responsible for 36% of EU’s CO2 emissions, directly related to energy consumption. Researchers say that there is a huge potential for energy savings in this sector, because the available technology is currently highly cost-effective, which could help to mitigate global energy use by the building sector. This study focuses on building performance aspects of an office building at TU/e, such as energy consumption and thermal comfort. EnergyPlus is used as a simulation tool to investigate energy-efficient opportunities, during the later phases of design process, and to research innovative applications for design support. However, buildings do not always perform as well as predicted. This performance gap may result from a number of reasons, but the most representative causes are introduced by uncertainties within the model design. For this reason, in recent years, the calibration of building simulation models has been of growing interest, mostly due to the lack of a recognizable approach to take during the entire calibration process. This paper presents a methodology to apply during model development and calibration optimization, for tuning a set of parameters, while highlighting the effects of uncertainty in the calibration process. The goal is to minimize the difference between predicted (simulated) energy performance and actual measured energy use. To assess the accuracy of the model, two statistical indices are calculated: the Mean Bias Error (MBE) and the Coefficient of Variation of the Root Mean Square Error (CV(RMSE)), which were found to be consistent with ASHRAE guideline 14 limits. After the model has been successfully calibrated and validated, other analyses may proceed. In this research, besides the building’s energy consumption assessment, the thermal comfort of the occupants is also evaluated in relation to Dutch guidelines, which are based on the ATG-method. The analysis conducted confirmed a “good” level of thermal comfort in the test case building, with less than 10% of its users experiencing discomfort.Trabalhos publicados mostraram que os edifícios normalmente consomem mais energia do que o necessário para o conforto dos ocupantes. O setor dos edifícios é responsável por 40% do consumo de energia final na EU e responsável por 36% das emissões de CO2, diretamente relacionadas com o consumo de energia. Investigadores dizem que existe um enorme potencial de poupança de energia neste setor, pois a tecnologia atualmente disponível é altamente económica, o que poderá ajudar a mitigar o uso global de energia pelo setor de edifícios. Este estudo centra-se em aspectos relacionados com o desempenho energético de um edifício de escritórios na TU/e, tais como o consumo de energia e o conforto térmico. O EnergyPlus é usado como ferramenta de simulação para investigar oportunidades energeticamente eficientes, após a período de ocupação de um edifício. No entanto, os edifícios nem sempre se comportam energeticamente tão bem quanto o previsto. Esta discrepância no desempenho pode ter uma série de razões, mas as causas mais representativas são introduzidas por incertezas referentes ao design do modelo de simulação. Por esse motivo, durante os últimos anos, a calibração dos modelos de simulação tem sido de crescente interesse, principalmente devido à falta de uma abordagem reconhecida a ser tomada durante o processo de calibração. Este trabalho apresenta uma metodologia a aplicar durante as técnicas de desenvolvimento e calibração do modelo de simulação, ajustando um conjunto de parâmetros, enquanto destaca os efeitos das incertezas no processo de calibração. O objetivo é minimizar a diferença entre o consumo de energia previsto (simulado) e consumo de energia medido. Para avaliar a precisão do modelo, dois indicadores estatísticos são calculados: o erro quadrático médio (MBE) e o coeficiente da raiz de variação do erro quadrático médio(CV(RMSE)), que foram considerados consistentes com os limites impostos pela norma 14 do ASHRAE. Após o modelo ser calibrado e validado com sucesso, outras análises poderão ser conduzidas. Neste estudo é também avaliado, além dos consumos energéticos, o conforto térmico dos ocupantes do edifício em relação à legislação holandesa, que se baseia no método ATG. A análise realizada confirmou um "bom" nível de conforto térmico no edifício em estudo, com menos de 10% de seus ocupantes a sentirem desconforto

DEST Software to Analyze System Zoning and Energy Consumption in Air Conditioning Systems

This paper reports on a study on how to appropriately divide system zoning by using DeST software to calculate the basis dynamic temperature and load of all rooms in an office building. Influent factors of weather conditions, building envelope conditions and building structure were analyzed in this simulation. We found that load was the fundamental factor involved in system zoning. Surplus heat recovery in inner zone is also recommended to maintain inner zone comfort and save energy

Analysis of Climate-Oriented Researches in Building

This research was supported by the Agencia Nacional de Investigación y Desarrollo (ANID) of Chile, through the projects: ANID FONDECYT 1201052; ANID PFCHA/DOCTORADO BECAS CHILE/2019—21191227; and research group TEP-968 Tecnologías para la Economía Circular of the University of Granada, Spain.The following are available online at https://www.mdpi.com/article/10 .3390/app11073251/s1, Table S1: Studies of Cluster 1; Table S2: Studies of Cluster 3; Table S3: Studies of Cluster 4; Table S4: Studies of Cluster 9; Table S5: Studies without cluster.Many factors and aspects of the construction and operation of buildings depend on climatic parameters and climatic zones, so these will be fundamental for adapting and mitigating the effects of climate change. For this reason, the number of climate-oriented publications in building is increasing. This research presents an analysis on the most-cited climate-oriented studies in building in the period 1979-2019. The main themes, the typologies of these investigations and the principal types of climatic zoning used in these studies were analysed through bibliographic and manual analysis. A broad spectrum of themes directly and indirectly related to climate and climatic zones and buildings was demonstrated. It was found that 88% of all climate-oriented investigations, to one degree or another, are within the scope of the general topic of energy conservation. A thorough understanding of all climate-dependent aspects will help in designing dwellings appropriately in different climate zones. In addition, a methodology that facilitates the establishment of a typology of climate-oriented research is presented. This typology can be used in future research in different scientific areas. It was also revealed that the climate zones of the National Building Codes of China, the USA and Turkey prevailed in the studies analysed.Agencia Nacional de Investigacion y Desarrollo (ANID) of Chile ANID FONDECYT 1201052 ANID PFCHA/DOCTORADO BECAS CHILE/2019-21191227research group TEP-968 Tecnologias para la Economia Circular of the University of Granada, Spai

EFFECT OF ADAPTIVE COOLING TECHNIQUE ON ENERGY USAGE PATTERNS OF A CENTRALIZED HVAC SYSTEM

Nowadays, due to world energy crisis and global warming, efforts to reduce energy consumption become doubled. One of the efforts is to find strategies for lower energy consumption by the centralized HVAC system since the system is a major energy consumer in many building. Field studies conducted by many researchers in many countries have found that adaptive comfort temperature (ACT) for naturally ventilated and air-conditioned building are higher than the recommended value. Previous works on this topic showed that using the ACT, around 20% of energy consumed by HVAC system could be saved without sacrificing people’s comfort. However, mechanical limitation of HVAC system, the effects of application of the indoor comfort temperatures on the HVAC system and its applicability for academic building has not been discussed in detail on previous research. Therefore, this work aims to develop adaptive cooling technique using ACT to reduce energy consumption of a centralized HVAC system in an academic building by taking into account design limitation, and effect of application of ACT on the HVAC system. The building model and its HVAC system were first built using a building simulation program (BPS), TRNSYS and validated by comparing the simulation results with experimental results. Adaptive cooling technique coupled with dual fan dual duct system was built as proposed technique for effective, efficient, and economical solution to reduce the energy consumption. The validated model was then used to analyze the performance of the HVAC system using current strategies and proposed technique. In case of academic bloc 16 in Universiti Teknologi PETRONAS, the results showed that the indoor comfort temperatures ranges during occupied and unoccupied periods were 24.29oC – 24.51oC and 28.04oC – 28.76oC, respectively, while the relative humidity was constant at 70%. The proposed technique is able to reduce the cooling load up to 28.54% and has payback period less than 5 years

A study of occupancy-based smart building controls in commercial buildings

Occupant behavior has a significant influence on energy consumption in buildings because HVAC, lighting, equipment, and ventilation operations are often tied to occupancy- based controls. However, currently, the traditional methods for the prediction of occupant behavior using a building energy modeling approach has begun to face difficulties due to the complex nature of occupant behavior and the introduction of the new technologies (i.e., occupancy sensors) in new and renovated construction. Research in the previous studies revealed that actual occupancy rates in office buildings were quite different compared to typical simulation schedules used in the analysis of building codes and standards. Therefore, large potential energy use reductions are expected when occupancy-based controls are used in building operations. In addition, many workers are recently encouraged to work more at home, which may cause larger unoccupied periods for a significant portion of time at a commercial office building. This fact further increases the need to better understand various occupancy schedules and usage trends in building energy simulations. However, currently, the U.S. commercial building energy codes and standards (i.e., ASHRAE Standard 90.1) do not fully support building energy modeling for occupancy-based controls for code-compliance. Performance paths (i.e., Appendix G method) in Standard 90.1- 2016 offer only partial credits for occupancy-based lighting controls, which tend to underestimate the potential reduction from the use of occupancy-based controls. Also, the requirements of the ASHRAE Standard 90.1 performance path require the mandatory use of identical schedules for the baseline and the proposed design models, which do not present the calculation of reduction from occupancy-based controls. Therefore, this study seeks to analyze occupancy-based controls to determine how varying factors may impact energy use reduction predictions in commercial office buildings. These factors include: different building types (i.e., lightweight versus heavyweight), with different system types (e.g., variable air volume versus packaged single-zone systems) by orientation (i.e., N,S,E,W) in different climates (e.g., cold and hot climates). To achieve the goal of this study, a reference office building was analyzed based on the prototype office building model that was developed by the U.S. DOE and PNNL for small office building for Standard 90.1-2016. Using this model, different thermal zoning models were developed for single-zone and five-zone models to evaluate the impact of occupancy-based controls in the prototype office building. The impact of occupancy-based controls was then evaluated using simulation to study the influence of occupant behavior on HVAC, lighting, equipment, and ventilation system energy use. A sensitivity analysis of each occupancy control schedule (i.e., occupancy, lighting, equipment) was performed in 100%-0% variations to determine interactions between occupancy variables. In addition, simulations for a set of specific occupancy control schedules (i.e., occupancy, lighting, equipment) were conducted in hot-humid and cold-humid climate zones with different building designs (i.e., a raised floor lightweight building and a heavyweight building with varying window-to-wall ratios) and different HVAC system types (i.e., packaged variable air volume versus packaged single-zone systems) to identify potential energy use reduction of occupancy-based building controls on annual energy consumption. The results showed substantial energy reduction potential from varying factors related to occupancy-based controls in commercial office buildings. The evaluation in two climate zones showed a range of energy reduction in Houston and Chicago due to the weather-dependent loads (i.e., heating, cooling, ventilation). Heavyweight material models showed higher percent energy use reduction potential ratios and less energy use compared to the reference building and lightweight models. Also, smaller window-to-wall models represented less total energy use than higher window-to-wall models, which led to higher energy use reduction ratios for smaller window-to-wall ratios. The PVAV systems had higher total load reduction ratios and less total energy use than PSZ systems in Houston and Chicago, especially for heating loads. Whole-building occupancy-based controls revealed more energy use reduction potential ratios in Houston compared to Chicago. The impact of orientation was different depending on thermal zone locations. However, the impact was not fully analyzed because this study did not evaluate combined occupancy sensor controls, daylight controls, and daylighting-based schedules. The largest energy use reduction contributors to occupancy modeling were the internal load factors (e.g., lighting, equipment). The outcome of this study should help guide the development of a guideline for evaluating how occupancy-based building controls can be better incorporated in different building types for different climate zones to reach compliance with ASHRAE Standard 90.1- 2016

The impact of architectural design criteria on energy performance of residential buildings: A case study in İzmir

Thesis (Master)--İzmir Institute of Technology, Architecture, İzmir, 2012Includes bibliographical references (leaves: 101-107)Text in English;Abstract: Turkish and Englishxi, 162 leavesThe impact of architectural configuration and design norms on energy performance of buildings has been a critical issue. Even, it becomes noteworthy for residential buildings of good quality. New legislation in Turkey which was prepared to comply for the latest European Energy Performance of Buildings Directive 2010/31/EC requires information about the evaluation of energy performance of existing buildings. So, this study aimed to determine energy performance of residential buildings in Izmir, to analyze significant relationships between their performance and architectural configuration through statistical analyses (analysis of variance (ANOVA), regression, t-Test, scatter charts). Utilizing production drawings, certain area-based ratios and building dimensions were determined as architectural configuration indicators. Most prevailing architectural variables, such as, zoning status, external surface area and A/V ratios, and others, namely, orientation, floor counts in a building, aspect ratio, heating system were analyzed. Energy performance of case buildings were determined by using The Standard Assessment Method for Energy Performance of Dwellings (KEP-SDM) which referred to Turkish standard TS 825, and European standard EB ISO 13790. Majority of the investigated buildings were in Energy Class B and C, in CO2 Class G; however, their energy consumption values were two times higher than the ones in European countries. Findings present such a clue that interactions between variables and their total effect on the energy performance and CO2 emissions should be taken into consideration. They would also provide feedback information on the residential building stock in İzmir, selected as a representative city in Turkey

A three-stage optimization methodology for envelope design of passive house considering energy demand, thermal comfort and cost

Due to reducing the reliance of buildings on fossil fuels, Passive House (PH) is receiving more and more attention. It is important that integrated optimization of passive performance by considering energy demand, cost and thermal comfort. This paper proposed a set three-stage multi-objective optimization method that combines redundancy analysis (RDA), Gradient Boosted Decision Trees (GBDT) and Non-dominated sorting genetic algorithm (NSGA-II) for PH design. The method has strong engineering applicability, by reducing the model complexity and improving efficiency. Among then, the GBDT algorithm was first applied to the passive performance optimization of buildings, which is used to build meta-models of building performance. Compared with the commonly used meta-model, the proposed models demonstrate superior robustness with the standard deviation at 0.048. The optimization results show that the energy-saving rate is about 88.2% and the improvement of thermal comfort is about 37.8% as compared to the base-case building. The economic analysis, the payback period were used to integrate initial investment and operating costs, the minimum payback period and uncomfortable level of Pareto frontier solution are 0.48 years and 13.1%, respectively. This study provides the architects rich and valuable information about the effects of the parameters on the different building performance

Champs-Multizone and Virtual Building for Integrated Building Systems Design and Performance Evaluation

The ultimate goal of this research was to develop an integrated framework that facilitates performance-based multi-stage design of buildings and comparison between the performance predicted at the design stage and that monitored at operation stage. Such an integrated framework would not only enable design optimization, but also enable confirmation of design intent or diagnosis of performance deficiency, and thus provide feedbacks for future building design. This dissertation study represents the first step toward this ultimate goal, and had the following specific objectives:: 1) developing a combined heat, air, moisture and pollutant transport model for whole building performance simulation; 2) developing a real-time building IEQ and energy performance monitoring system using a Virtual Building structure to facilitate fast comparison between design and montored performance.; 3) developing a methodology to use CHAMPS-Multizone for a green building design throughout its initial and final design stage. The CHAMPS-Multizone model consists of building envelope model, room model, HVAC model and airflow model, and has an efficient and accurate numeric solvers. The model is tested under different building cases including ASHRAE 140 standard test and a three zones building test and comparision with EnergyPlus calculation results. The Virtual Building is a digital representation of the physical building with a hierarchical data structure, containing both static data such as enclosure assemblies, internal layout, etc. and dynamic data such as occupant activity schedule, outdoor weather conditions, indoor environmental parameters, HVAC operation data and energy consumption data. Then, the Virtual Building approach has been demonstrated in a LEED office building with its monitoring system. Finally, a multi-stage design process was formulated that considers the impact of climate and site, form and massing, external enclosure, internal configuration and environmental system on the whole building performance as simulated by CHAMPS-Multizone. Using the testbed building, both simulation results were also compared with the results monitored by the Virtual Building monitoring system. Future research includes refining CHAMPS-Multizone simulation capability and adding modules such as water loop calculation and integrating HVAC calculation with EnergyPlus