Ensuring Effective Energy Management in Green Buildings Using Building Energy Simulation

Detailed analysis is required to determine the complicated characteristics of energy performance of buildings. Before a building is constructed, building energy performance simulation software can be used to gain insights into the building’s eventual energy performance (Jayalath, 2020). The software is used to simulate the ‘dynamic interaction’ of heat, light and mass within the building in order to predict its energy and environmental performance as it is exposed to climate, occupants and conditioning systems (Ho, 2017). Having an idea of the energy performance of a building will allow the stakeholders to make vital decisions about the building’s design, operation and management. The simulations may be repeated several times and the results from the simulations may be used to finetune the building design until the targeted energy efficiency of the building is achieved. Additionally, it helps to reduce the risk of having to modify systems during later stages of construction which is a costly affair. The results generated from the simulation also provides vital information for evaluation of life cycle cost of a building.

To gain valuable points in the energy optimisation aspects, green buildings applying for certifications such as LEED and GreenSL rating systems should have superior performance when compared to the ‘baseline building rating’ mentioned in ASHRAE/IESNA Standard 90.1 Appendix G and this should be sufficiently proven by the use of building energy simulation.

The building energy simulation process consists of several steps. Firstly, a suitable simulation software has to be selected according to the required complexity of the simulation (Ho, 2017):

• Simple software where an overall energy consumption assessment can be carried out (e.g.: eQUEST, TRACE 700, etc)
• Sophisticated software which allow periodical simulation of the building’s energy performance (e.g.: EnergyPlus, TRNSYS, etc)
• Complex specialist software which integrates methods such as computational fluid dynamics and 2 and 3-dimensional conduction analyses.

The building and building services systems are represented in the simulation software by constructing a simulation model. Data are input into the software corresponding to different scenarios which can be expected during the lifetime of the building. After running simulations for each of these scenarios, the simulation results are used for further analysis. Care must be taken to ensure that the correct input is made into the software. If incorrect data is input, it may produce misleading analyses (garbage in- garbage out concept) which can have extremely adverse effects on the building’s eventual performance.

Applying correct zoning (usually thermal zoning) for the building during the simulation is beneficial for easier understanding of its performance and simplifying the process. For instance, zoning maybe done according to the use of the space or according to the expected thermal loads. Correct zoning can also minimise repetition of work as zones maybe considered as typical for several sections of the building.

In conclusion, building energy performance simulation software offers a powerful tool for stakeholders in the design, construction, and operation of buildings. By simulating the dynamic interactions within a building, the software predicts energy use and environmental impact, allowing for informed decision-making throughout the building's lifecycle. This not only optimizes energy efficiency and reduces construction costs, but also provides valuable data for life cycle cost analysis and green building certifications. By carefully selecting appropriate software, creating accurate building models, and employing proper zoning techniques, building energy simulation software empowers stakeholders to create high-performing and sustainable buildings.

References

Ghiassi, N., 2013. Development of a Building Data Model for a Performance-Based Optimization Environment, Vienna: Vienna University of Technology.

Ho, B. P. L., 2017. Building Energy Management. Hong Kong: Department of Mechanical Engineering, The University of Hong Kong.

Jayalath, M. S., 2020. Sustainable Buildings: Energy Management: Methods & Techniques. Colombo: Green Building Council of Sri Lanka.

TRANE, 2019. How do I model an attic in TRACE 700?. [Online] Available at: https://tranecds.custhelp.com/app/answers/detail/a_id/42/~/how-do-i-model-an-attic-in-trace-700%3F/session/L2F2LzEvdGltZS8xNjA1MjAwMDU2L2dlbi8xNjA1MjAwMDU2L3NpZC9mVUtheCU3RXd3WmVYMHRxY1pIeHFxbEkzNmdTN0xUajFTJTdFNGR1YnE2VzZrZFo4bW5MV2dIZmlsbkZfcl9fOXRrVkIy