BENV0084 – Building Systems Physics MSc in Smart Buildings and Digital Engineering Institute for Environmental Design and Engineering COURSEWORK OVERVIEW Module: BENV0084 – Building Systems Physics Coursework: Analysis of the influence of physical properties on the dynamic performance of a building Component Weighting: 60% of total module mark Coursework Issued: 27th November 2023 Submission Deadline: 11th January 2024, 11:00AM Word Limit 1800 words Page Limit None File format Submit your report online as a single Word or PDF file. In addition, you should submit (as a single zip file) all models you created and key output files (as required in the brief below). Submission instructions ALL students to submit a complete electronic copy of coursework submission through Moodle (and the Turnitin system). This is the copy that will be used to assess the work, so it is the FINAL copy. Submit your report online as a single Word or PDF file. Use the provided cover page and make sure not to include your name anywhere (including the name of file) – use your candidate code instead. In addition, you should submit separately (as a single zip file) all models you created and key output files (as required in the brief below). In preparing your report, make sure you use the cover page provided and you check your work for plagiarism. You should name all your files according to the convention: [Module code]_[Your UCL candidate code]_[date] BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 2 Coursework Aims (Learning Outcomes) Upon successful completion of the coursework, the student should be able to: ▪ Perform detailed calculations to effectively evaluate the performance of the building and its engineered systems. ▪ Assess the impact of parametric variation on a building, its components and engineered systems. ▪ Explain and interpret the underlying input and output factors, and assess their sensitivity, that are essential for the meaningful application of components in building modelling and simulation software. Overall Brief This coursework will consist of a series of tasks, which should be carried out sequentially and submitted at the end of term: Task 1: implement a lumped capacitance model, incorporating all key physical processes such as infiltration, ventilation, transmission and thermal storage. Task 2: perform a comparative analysis of the building performance of a lightweight and heavyweight building, considering different ventilation regimes and setpoint schedules. Task 3: perform a sensitivity analysis to identify the key parameters affecting the building performance of one building type and discuss the results. Resources needed to complete this coursework The lecture slides provide information for the heat transfer calculations of building elements; additional suggested resources are recommended in the module Moodle page. BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 3 Task 1: Lumped capacitance model 1.1) Problem statement Implement a lumped capacitance model of a building. The aim of the first task is to implement a lumped capacitance model of a building, describing at least the following processes: • Infiltration heat transfer • Ventilation heat transfer • Transmission heat transfer • Solar heat gains through windows • Solar energy absorption at building surfaces • Thermal storage in walls The model is based on Gori1 (2017) and it is extended to include most elements of the heat balance equation of a building. In this exercise, please assume that there is no heat exchange between the floor and the soil. The model should by implemented in Python, the script you created should be submitted along with your coursework report. 1.2) Required outputs The outputs of this task are: • the equivalent circuit, and • a system of linear equations, which will be used in Task 2 to determine the temperatures at the nodes and the heat flows through the building fabric. Make sure you clearly describe the resulting equivalent circuit and the key assumptions in your model. 1 V. Gori, “A novel method for the estimation of thermophysical properties of walls from short and seasonally independent in-situ surveys.” Doctoral thesis. University College London, 2017 BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 4 Task 2: Parametric analysis 2.1) Problem statement Perform a comparative analysis of the building performance of a lightweight and a heavyweight building located in Cardiff (UK), using dimensions and material properties based on the BESTEST cases 600 and 900. a. Introduce and justify your input assumptions: Introduce and justify the input assumptions for the comparative analysis, including the selected ventilation regimes and setpoint schedules (see point c.). b. Calculate the annual space heating demand for a building: • Use the implemented lumped capacitance model to run an annual simulation for a lightweight and a heavyweight building (see 2.2 for input data) and obtain the heat flows through the building fabric. • Calculate the space heating demand for each building. • Analyse and discuss the results in detail for a building (i.e. lightweight or heavyweight), considering the contribution of each of the heat transfer and storage processes (see Task 1) to the results. c. Identify the weeks with highest difference in space heating and cooling demand: • Using the annual simulation in Task 2b, calculate the cooling demand for the lightweight and heavyweight building. • Identify the week (i.e., seven consecutive days) with the highest difference in heating demand between the lightweight and the heavyweight building and describe the selection process. • Identify the week (i.e., seven consecutive days) with the highest difference in cooling demand between the lightweight and the heavyweight building and describe the selection process. d. Perform the comparative analysis considering different ventilation regimes and setpoint schedules: • Considering a constant ventilation regime and a suitable schedule for the heating and cooling set point temperature, compare the building performance of a lightweight and heavyweight building in the selected weeks, considering heat flows through the building fabric. • Consider two ventilation regimes: one with a constant rate throughout, and one with a daytime ventilation rate and a night-time ventilation rate. Assess and discuss the influence on the building performance (for the selected weeks) for lightweight and heavyweight buildings. • Compare the results for the defined setpoint schedule with those for a constant setpoint temperature. Assess and discuss the influence on the building performance (for the selected weeks) for lightweight and heavyweight buildings. 2.2) Input data A general description of the two buildings and the modelling data required, loosely related to the BESTEST case study buildings, is given in Appendix 3 of this brief. If any other information is needed, BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 5 you should look for suitable input data in the literature and justify the selection using the appropriate reference. As indoor temperature, you should select a suitable schedule for the heating and cooling set point temperature. You can derive this information from data measured from UK buildings, or from appropriate guidance documents. You should justify your data selection. Regarding the climate data, use a hourly climate file for Cardiff (UK), which can be found in .epw format; please cite your data source appropriately. Note that the climate file should include dry bulb temperature [oC], direct normal irradiation [Wh/m2] and diffuse horizontal irradiation2 [Wh/m2]. Make sure you are consistent with the units when using the climate parameters. Regarding the ventilation regimes, use relevant resources to identify suitable ventilation rates for each strategy and state your assumptions on the selected ventilation rates. 2.3) Required outputs for the calculation of the annual space heating demand For each test case, a model should be created using the lumped capacitance method, as implemented in Task 1. For each model, run annual simulations and export the annual space heating demand over the entire simulation period. Analyse and discuss the results. 2.4) Required outputs for the selection of weeks From the annual simulations in Task 2b, export the weekly heating and cooling demand over the entire simulation period. Identify the weeks with highest difference in heating demand and cooling demand between the lightweight and heavyweight building. Please describe the process of selection of the weeks and provide the calculations. 2.4) Required outputs for the comparative analysis Describe and justify the input assumptions, including the ventilation regimes and the setpoint schedules selected. Introduce the concepts of lightweight and heavyweight buildings. Discuss the differences (if any) on the predictions of the heat flows and the overall building performance for the selected weeks using the lightweight and heavyweight buildings, and considering two ventilation regimes and two setpoint schedules. 2 https://bigladdersoftware.com/epx/docs/8-3/auxiliary-programs/energyplus-weather-file-epw-data-dictionary.html BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 6 Task 3: Sensitivity analysis 3.1) Problem statement Perform a sensitivity analysis to identify the key parameters affecting the building performance of the building and contrast the results. The analysis should consider the influence of input parameters on the heating and cooling demand of one building, as well as the influence of the modelling assumptions and limitations. Discuss the results, focusing on the two weeks selected in Task 2. You should vary the parameters within an appropriate range, justifying the selected range. You should assess and discuss the relative importance of the parameters; a one-at-a-time sensitivity analysis is sufficient for the purpose of this coursework. 3.2) Input data Among the input parameters, you should change at least three of these parameters: • orientation, • internal heat gains, • material properties, • outdoor temperature, • surface properties. For the analysis of input parameters, please explain and interpret the selected input parameters and discuss their sensitivity. For the analysis of the influence of modelling assumptions, you may consider simplifying the lumped capacitance model and discuss the influence on the results. 3.3) Required outputs Perform a sensitivity analysis, considering the input data in 3.2. Analyse and discuss the results, considering the heating and cooling demand in the weeks selected in Task 2. You may also consider the heat flows through the building fabric in the selected weeks. Please discuss the influence of modelling assumptions on the results and the application to a real building. END OF COURSEWORK BRIEF, SEE APPENDIX BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 7 Appendix 1: Marking Scheme Assessment Criteria Weight (%) Rationale Introduction: aims of the coursework and background knowledge 5 The introduction helps setting the context for the reader and describe the aims and objectives of the coursework. This section is critical for allowing the quick transfer of knowledge to readers. Task 1: implementation of lumped capacitance model and assumptions 15 For replication and assessment, it is important to provide a clear and coherent methodology for the development of a model. Each model requires some assumptions to be made In a clear and concise way. Task 2: comparative analysis of lightweight and heavyweight building 45 (a.10, b.10, c. 10, d.15) Input assumptions should be clearly presented and justified. The process of selection of relevant weeks should be correct and clearly explained. Results should be analysed and discussed, with a focus on the annual heating and cooling demand and the selected weeks. The results may be supported by tables and charts and should lead to a discussion on the differences between the lightweight and heavyweight buildings, considering different ventilation regimes and setpoint schedules. Task 3: sensitivity analysis of one building 20 Results should be analysed and discussed, with a focus on two selected weeks. Understanding the quality of data used as an input to a model will ensure that there is a better understanding of the output. No matter how well designed and built a model tool is, outputs will be heavily dependent upon input values. A sensitivity analysis helps determining the impact / uncertainty of model inputs and model assumptions to the total model output. Conclusions 5 A good conclusion is succinct and highlights the main findings, limitations and future work that can be carried out in further modelling tasks to highlight additional areas of analysis. Presentation: structure, clarity and references 10 A well-built report is clearer to follow for the writer and the end- reader. This means that errors are less likely to occur and are easier to spot when they do. This reduces workload, costs and overhead at all later stages. Total 100 As a guide to the way this coursework will be marked, note that you are likely to receive a B if you include all the sections as mentioned above. If you make no obvious technical errors or incorrect assumptions and have applied a coherent analysis strategy to each of the modelling tasks, then you are likely to get a higher mark. Should you miss out some of the above sections, if you make many mistakes, if you go beyond the page limit you will have marks deducted. Please see below for additional details on the marking scheme. BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 8 Criterion Excellent Competent Needs Work Inadequate Introduction: aims and background knowledge 5% The information demonstrates deep understanding by using relevant and accurate detail to support the work that has been undertaken. Research is thorough and goes beyond what was presented in class or in the assigned texts. The section uses knowledge which is generally accurate with only minor inaccuracies, and which is generally relevant to work that has been undertaken. Research is adequate but does not go much beyond what was presented in class. The section uses little relevant or accurate information, not even that which was presented in class or in the assigned texts. Little or no research is apparent. No introduction. Aims or objectives are missing. Task 1: implementation of lumped capacitance model and assumptions 15% The methodology used is very clear, sensible and fit for purpose and is illustrated using appropriate methods used to describe it. The methodology used is somewhat clear and fit for purpose and is explained. The methodology used requires explanation. Analysis is missing or has big logical gaps. No explanation of the methodology. Task 2: comparative analysis of lightweight and heavyweight building 45% The data/assumptions are sound, clearly recorded, and properly referenced. The process of selection of relevant weeks is correct and clearly explained. Results are logical, clearly explained and the comparison of buildings is discussed in depth. The correct type of graph/tables is employed. The data/assumptions seem sound. The process of selection of relevant weeks is somewhat correct. Results are somewhat logical, and the comparison of buildings is discussed. The correct type of graph/tables is employed. The data/assumptions require validation. The process of selection of relevant weeks requires explanation. Results are questionable/most of the required outputs are missing. The graphs/tables require revision. Input assumptions are not stated, or they are very questionable. Results and discussion are missing to a large extent, or fail to address the coursework brief. Task 3: sensitivity analysis of one building 20% Input ranges are clearly presented and justified. The results and discussions are logical, Sensitivity analysis techniques are applied in analysis and the correct type of graph/tables is employed. Input ranges are sufficiently presented and justified. The results and discussions are somewhat logical. Some sensitivity analysis techniques are applied in the analysis and the correct type of graph, tables is employed. The justification of input ranges requires better clarity. The results and discussion are questionable / most of the required outputs are missing. No sensitivity analysis techniques are applied in the analysis and the graphs/tables require revision. Results and discussion are missing to a large extent or fail to address the coursework brief. Conclusions 5% The findings are clearly highlighted, and recommendations are discussed. Limitations are well-defined, and their impact discussed. Some findings are highlighted, and recommendations discussed. Some limitations of the modelling are defined. Some findings are highlighted. The limitations of the modelling task are not discussed. Conclusions section is missing or fails to address limitations. Presentation: structure, clarity and references 10% The structure and language is clear and coherent and the presentation includes easily understood visual aids which the author refers to and explains at appropriate moments in the report. Relevant literature is clearly referenced. The work is understandable and includes appropriate visual aids, but these are too few, in a format that makes them difficult to use or understand, and/or are not referred to or explained in the report. Relevant literature is referenced. The structure still needs to be developed and the presentation includes no visual aids or visual aids that are inappropriate, and/or too small or messy to be understood. The author makes no mention of them. Limited reference of literature. The structure is confusing, and the work is hard to understand. Layout demonstrates poor conceptual understanding. Many missing references and significant gaps in referencing. In the assessment, marks will be awarded for the following criterion, in the weighting shown. Pass grades are above 50%. BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 9 Appendix 2: Penalties for Exceeding the Word Limit and Late Submission Please note that there are penalties for submitting the coursework late and/or for exceeding the word or page limit. You can find all the course-specific rules in the online MSc SBDE handbook – go to the 8.1 Penalties page. A specified maximum length is provided for each coursework assignment. This might be a word count or may also be expressed in a maximum number of pages – check the first page to see what applies for this specific coursework. Part of the skill in writing coursework assignments is to make the most efficient use of the words available within the given limit. Complying with word limits is important as it helps students prepare for professional practice in many work situations and because allowing some students to write more than others may give them an unfair advantage. If the word/page count: The following penalty will apply: Is under the word/page limit No penalty will apply Exceeds the specified word/page limit by less than 10% Reduction by 5 percentage points. The penalised mark will not be reduced below the pass mark, assuming the work merits a pass. Exceeds the specified word/page limit by more than 10% Reduction by 10 percentage points. The penalised mark will not be reduced below the pass mark, assuming the work merits a pass. In the case of coursework that is submitted over-length and is also late (see below), the greater of any penalties will apply. Reporting an inaccurate word count incurs a 10%-mark penalty. What is included in the word count? The regulations for SBDE are: • Word counts include body text (from the title of the introduction to before the references section) and the body-text part of your references (name, year). • Abstract, table of contents, any list of figures and tables, acknowledgements, references, appendices, footnotes, endnotes, diagrams and captions are excluded. Data tables - tables which collate raw data (for example, the tabulated responses to a questionnaire) should be included in an appendix and are therefore not counted. In BENV0084, equations are also excluded from the word count. Students are advised that appendices and footnotes are to be used sparingly and must provide supporting information only. The content of these sections is not considered part of the main body of the assignment and will not contribute towards your grade. An electronic file must be submitted (preferably in pdf format), with the word count clearly stated at the front. If you are in any doubt, please discuss this with the Module Leader. BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 10 Penalties for Late Submission Planning, time-management and the meeting of deadlines are part of the personal and professional skills expected of all graduates. For this reason, UCL expects students to submit all coursework by the published deadline date and time, after which the following penalties will be applied. For any assessed component the following procedure applies: If the component is submitted: Component Mark 50.00-100.00% Component Mark 0-49.99% By the stated deadline (or agreed deadline where an extension has been granted) No penalty No penalty Up to 2 working days late: Reduction by 10 percentage marks; the penalised mark will not be reduced below the pass mark. No penalty 2-5 working days late Mark of 50% No penalty More than 5 working days late Mark of 1% Mark of 1% In the case of coursework that is submitted over-length and is also late, the greater of any penalties will apply. Please ensure you keep a full back-up copy of all the work you submit. Keep regular backups of your work (report, models). BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 11 Appendix 3: Physical properties for the lightweight and heavyweight buildings The building geometry and material properties for the case studies are adapted from the BESTEST building. A3.1) Building geometry A3.2) Common data A.3.2.1) Radiative properties External opaque surfaces: emissivity and absorption Infrared 0.9 Short wave 0.6 A.3.2.2) Infiltration data Infiltration (air change per hour) is to be set at 0.5 h-1 . A.3.2.3) Initial conditions All initial temperatures are to be set at 10 oC . BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 12 A.3.2.4) Window properties The general window properties are as follows: A.3.2.5) Roof properties BENV0084: Building Systems Physics MSc in Smart Buildings and Digital Engineering 13 A3.3) Lightweight building A.3.3.1) Wall properties A.3.3.2) Floor properties A3.4) Heavyweight building A.3.4.1) Wall properties A.3.4.2) Floor properties