Energy Performance Modelling of a Multi-storey Office Building

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

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

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

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

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).

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

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 section4.2.3.

c. Compare the predicted energy consumption with good practice benchmarks given in CIBSE Guide F (CIBSE 2012), Table 20.1

Learning Outcomes

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.

Local planning regulations limit the height of building developments in this location to 15m. Assume the building is to be heated, with a heating set-point of 20°C, from 1st January to 30th April, and from 1st October to 31st December, during occupied hours. If the building needs to be cooled during the winter, then assume the cooling setpoint based on your research, and what you think
building occupants in Turkey would feel comfortable at in the Summer.

Occupancy densities are 1 person per 10m2 on the ground and first floor and 1 person per 5m2 on the second floor. Occupants are present from 8am until 6pm with 20% occupancy for the first hour, the last hour and the period midday until 2pm, Monday to Friday. At all other times, you should assume that the building is unoccupied. The lobby areas and stairwell are transition spaces and should be modelled as unoccupied.

Assume each person is using a personal computer and there is a printer for every 15 people. You should also account for lighting gains of 8W/m2 on all floors. No other internal heat gains are present. Details of heat gains from computers and people can be found in CIBSE Guide A (CIBSE 2016).

Assume that there are similar height buildings on the east and west sides of the building, that there is a large enclosed car park area on the north side of the building and that there is a large open space on the south side of the building.

You are welcome to use a building location, modelling assumptions and assessment criteria applicable to your home or another country, provided that you clearly state what assumptions and assessment criteria you are using and that you reference the source of those assumptions and assessment criteria. If you choose to do so you should use a corresponding weather file when conducting the simulations.

• Front cover, which should include:

Project title

Author

The issue date

Confidentiality statement

• Executive summary

A few paragraphs summarising the work carried out and the major findings, in a style suitable for a non-technical reader.

• Introduction

A brief description of the building, its usage and the work carried out.

A statement describing which modelling techniques were employed and why.

• Statement of all the assumptions you made when building the computer model. Including:

Building construction – the makeup of the building elements and their overall U-Values.

Internal gains – people, computers and lights, etc.

Building occupancy – when people are present.

Environmental conditions (weather data used).

• Results, which should include:

A table of results from task 5 parts (a) and (b) and a statement regarding the predicted building performance in relation to performance criteria.

A statement detailing the predicted annual energy consumption and how this compares to UK energy benchmarks