Tag: climate data

Simulation of Buildings Using Real-Time Weather Data – by Veronica Soebarto

Building performance simulation is often used to assess the performance of an existing building, diagnose the main issues or identify existing problems, and investigate various strategies to ratify the problems and improve the building performance. Although it may seem straight forward, simulating an existing building is actually not simple, because, first, you need to ensure that the model accurately represents the actual building in terms of the geometry, envelope materials used and their thermal properties, as well as all the internal loads and use patterns. The second fundamental step in simulating an existing building is to compare the simulation results to measured data and to calibrate the model to minimize the discrepancies between the two.

In order to do this comparison, it is crucial to use the actual weather data file for the same period as the measured data. This is unfortunately often not done by many building simulators. Instead, they often use a standardised climate data file (e.g. TMY, EPW) that is more readily available. This is problematic, because there is no way you can adequately compare the simulation results to the data from the actual building, if you use a synthetic climate data file. Actual building performance, such as indoor temperature or cooling/heating energy use, is affected by the actual weather conditions; simulation results from running the simulation model with a standardised climate data file will only reflect the building performance as affected by those synthetic weather conditions.

Unless you install your own weather station for the location of the building you are simulating, there is almost no way you can obtain actual hourly weather data file. This is where Exemplary Energy plays a significant role in simulating existing buildings in Australia as they are able to provide the required actual weather data file for many locations in Australia. For more than 20 years, Exemplary Energy has been able to provide actual weather data files for our research at The University of Adelaide where simulating existing buildings is necessary.

Below are examples of the simulated hourly indoor temperatures versus measured data from our previous ARC Discovery Project where we monitored more than 50 homes of older people in South Australia. Exemplary Energy provided the actual weather data file (in EPW) for Adelaide (house 1) and Victor Harbor (houses 2 and 3). As can be seen here, the simulation model well represented the actual building as shown in the simulated indoor temperatures that compared well with the measured data.

Author: Professor Veronica Soebarto

School of Architecture and Civil Engineering

Faculty of Sciences, Engineering and Technology

University of Adelaide

https://researchers.adelaide.edu.au/profile/veronica.soebarto

Veronica joined the University of Adelaide in 1998 after completing a Post-Doctorate Research Associate position at Texas A&M University in College Station, Texas, USA, and PhD and Master of Architecture degrees from the same university. Her research interests span from age-friendly built environment, environmental performance assessments of buildings, building performance simulation, building monitoring, human thermal comfort, to the social dimension of sustainable design.

Images shown in this article are from a paper published in Journal of Building Performance Simulation: Arakawa Martins, L., Williamson, T., Bennetts, H., & Soebarto, V. (2022). The use of building performance simulation and personas for the development of thermal comfort guidelines for older people in South Australia. Journal of Building Performance Simulation, 15(2), 149-173.

2023 – the warmest year on record?

Mid-2023 has marked a significant period in climate change history, characterized by a series of global and regional heat records. According to an article from the Yale Climate Centre republished by Renew Economy, the single warmest day on record globally occurred in July 2023, and the month of June 2023 was also the warmest June in a 45-year dataset. Global sea surface temperatures have reached unprecedented highs, particularly in the North Atlantic, and the Antarctic sea ice has been slower to grow this year, with the extent well below previous record lows.

The primary driver of these heat records is global warming resulting from human activities. Billions of tons of greenhouse gas emissions from fossil fuel burning continue to be released into the atmosphere each year, and although the rate of emissions is increasing by “only” around 1% per year, the warming effect will persist until net-zero emissions are achieved.

The oceans store almost 90% of the energy trapped by greenhouse gases, and even a minor shift in oceanic warmth can significantly impact the atmosphere. The global ocean has been storing a larger share of energy since 2020 due to a rare 3-year-long La Niña event, and now that the earth is transitioning to El Niño conditions, additional heat is being transferred from the deep ocean to the surface and the atmosphere. El Niño events have historically led to global temperature records, and it is plausible that 2023 and 2024 could surpass previous records. The accumulation of greenhouse gases will have long-lasting and catastrophic effects on Earth’s climate for centuries or even millennia, and climate scientists highlight the urgency of reducing emissions and implementing strategies to mitigate climate change’s far-reaching consequences.

This is the strongest of corroborations for the urgent need for an updated design climate data set for building energy simulation – outdated climate data will produce inaccurate energy performance estimates and poorly optimised systems. Updates to the data are essential for both the energy efficiency provisions in the NCC Section J approval process and NatHERS as well as for design optimisation and outperformance such as NABERS Energy and Green Star ratings.

Exemplary Energy is filling that void. Full data sets for the era 1990-2022 are available now for all Australian capital cities; and our program aims to complete the data for all NatHERS Climate Zones by the end of August. In parallel with that work, we will be producing latest-15-years Reference Meteorological Years (RMYs) and eXtreme Meteorological Years (XMYs) to represent our current climate.