Reference no: EM132603723

ENGT5261 Building Performance Modelling - De Montfort University

Assignment : Assessment of an office building

Learning outcome 1: Use understanding of building physics, and apply modelling techniques in realistic building energy simulation exercises.

Learning outcome 2: Students will be able to critically evaluate energy, thermal, airflow, solar and daylighting simulation results and use them to make coherent recommendations.

Learning outcome 3: Write technical reports on climatic and building analysis in a form suitable for clients to a high standard.

Assignment brief
In this assignment you are required to use IES to model the thermal and energy performance of a multi-storey office building.

Outline
You have been commissioned by the project manager responsible for the development of a small office building to be built in Ankara, Turkey. Your role is to assess the thermal performance and energy performance of the proposed concept design. The client wishes to minimise energy consumption whilst maintaining a comfortable indoor environment. The architect has therefore proposed a naturally ventilated building in an attempt to avoid the use of air conditioning. However, doubt has been expressed about the suitability of this approach to deliver adequate performance. You have therefore been commissioned to carry out an initial assessment based on an assumption that natural ventilation without mechanical cooling can provide adequate ventilation for at least most of the year (a detailed assessment of natural ventilation and daylight performance will be the subject of a separate study).

Tasks

1. Construct the building geometry as shown in Appendix A below using IES ModelIT.

2. Implement a simple fixed rate ventilation strategy based on the natural ventilation rates recommended in CIBSE Guide A (CIBSE 2016).

3. Implement an appropriate heating (and if necessary cooling) strategy to ensure that comfortable indoor conditions are maintained during working hours. Use the heating set-point given below (and include an appropriate cooling set-point if necessary).

4. Include sources of internal gain as listed below.

5. Carry out a dynamic thermal simulation over a typical year using appropriate local weather data.

6. Carry out an evaluation of the thermal comfort and indoor air quality predicted in the occupied spaces and the overall energy consumption of the building.
a. Determine if the predicted dry-resultant temperature in each occupied room exceeds the maximum recommended temperature for offices given in CIBSE Guide A (CIBSE 2016), Table 1.5.
b. Determine if the predicted indoor air quality in each occupied room meets the IDA2 standard given in CIBSE Guide A (CIBSE 2016), section 4.2.1 and section 4.2.3.
c. Compare the predicted energy consumption with good practice benchmarks given in CIBSE Guide F (CIBSE 2012), Table 20.1

7. Write a technical report documenting your findings and making recommendations for improvements to the building design. These could include recommendations for changes to the building layout.

Assignment B: Design improvements to a multi-storey office building

In this assignment you are required to use IES to model design improvements to the multi- storey office building you evaluated in Assignment A (the building details are the same).

Learning outcomes
On completing this assignment you will be able to:
• Use dynamic thermal simulation, coupled with a nodal airflow model, to assess the thermal performance, ventilation performance and energy performance of the building
• Use computational fluid dynamics techniques to investigate spatial parameters such as temperature stratification, fresh air distribution and human comfort factors such as air temperatures and velocities.
• Investigate the effect of different natural ventilation schemes on indoor environmental quality
• Use daylight modelling to assess the daylight potential of a building and to investigate the effectiveness of solar shading for reducing solar gain and solar penetration
• Write a client report making recommendations for design changes to improve the thermal, ventilation and daylight performance of the building

Outline
You have again been commissioned by the project manager responsible for the development of a small office building to be built in the Ankara area to develop and evaluate design improvements to the building assessed in assignment A. The client wishes to minimise energy consumption and is keen to minimise use of air conditioning if possible. You are therefore required to develop and evaluate a natural ventilation scheme for the building which is capable of maintaining adequate indoor air quality throughout the year. The client has also expressed a desire that the building should have a generally day-lit appearance and so you are also required to develop and evaluate a daylight design to achieve this, including solar shading where necessary. You are also required to assess the impact on energy consumption of your recommended ventilation and daylight designs.

You are encouraged to consider an alternative building configuration, providing that it maintains the usable floor area and that it will fit within the constraints of the site.

Tasks

1. Consider your findings and recommendations from Assignment A, along with the new requirements outlined above, and construct an appropriate building geometry using ModelIT, within the context and constraints imposed by the site shown in Appendix A below.

2. Include glazing as appropriate to achieve good daylight performance, considering the need for ventilation openings.

3. Design and implement a natural ventilation scheme to achieve the natural ventilation rates recommended in CIBSE Guide A (CIBSE 2016). Make use of windows for ventilation as appropriate.

4. Implement an appropriate heating (and if necessary, cooling) strategy to ensure that comfortable indoor conditions are maintained during working hours. Use heating (and cooling) set-points based on recommendations in CIBSE Guide A (CIBSE 2016).

5. Include sources of internal gain as listed below.

6. Carry out a dynamic thermal simulation, coupled with nodal airflow modelling, over a typical year using appropriate local weather data.

7. Carry out an evaluation of the thermal comfort and indoor air quality predicted in the occupied spaces and the overall energy consumption of the building.
a. Determine if the predicted dry-resultant temperature in each occupied room exceeds the maximum recommended temperature for offices given in CIBSE Guide A (CIBSE 2016), Table 1.5.
b. Determine if the predicted indoor air quality in each occupied room meets the IDA2 standard given in CIBSE Guide A (CIBSE 2016), section 4.2.1 and section 4.2.3.
c. Compare the predicted energy consumption with good practice benchmarks given in CIBSE Guide F (CIBSE 2012), Table 20.1

8. Use computational fluid dynamics to verify the function of the natural ventilation scheme and to assess the thermal comfort and indoor air quality achieved for the building occupants, for appropriate time of year and weather conditions.

9. Evaluate the daylight performance of the design.

10. Consider the findings from tasks 6, 7, 8 and 9, and make any changes required to optimise the overall performance of the design, including the addition of solar shading and changes to construction materials as appropriate. Repeat tasks 6, 7, 8 and 9 as appropriate with the revised design, as required.

11. Write a technical report documenting your findings and recommendations.

Attachment:- Building Performance Modelling.rar