Studying the Impacts of Climate Change on the Building Design Conditions in Madison, Wisconsin

Global climate change, linking increased concentration of greenhouse gases (GHGs) with global warming, has been a worldwide concern. Although climate change occurs naturally, the concern is potential for human activities to enhance the greenhouse effect. Human activities in heating, ventilating, air conditioning and refrigerating (HVAC&R) systems contributes to GHG emissions through direct (CFCs, HCFCs, and HFCs) and indirect emissions (CO2) associated with the energy needed for operating buildings and building systems. The usage of HVAC&R system is highly impacted by future climate and weather. For example, the time in a year that people use air conditions or heating system depend on how warm the year is. The American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) creates an ASHRAE Climate Conditions Chart, which covers meteorological metrics including annual heating and humidification design conditions, annual cooling and dehumidification design conditions, extreme annual design conditions, monthly climate design conditions. This chart was calculated for 6443 locations around the world, and it is commonly used for design, sizing, distribution, installation, and marketing of HVAC&R systems, dehumidification equipment and other energy-relating processes in or out of the building. Knowing the climate design conditions over a location form ASHRAE chart, people can adapt the design of building energy systems to minimize energy usage, optimize energy efficiency, and therefore decrease the associated GHG emissions.

In this study, the university of Wisconsin-Madison research group will answer the research question: how will be building design specifications change under a changing climate. For answering this question, ASHRAE-equivalent metrics for Madison (Dane County), Wisconsin are recalculated and will be compared during past time (1986-2010), mid-century (2040-2060) and late century (2070-2100). Downscaled climate data form Wisconsin Initiative for Climate Change Impact (WICCI) is used for past time and mid-century calculations. WICCI data have been created based on 24 underlying models, including ACCESS1-0,ACCESS1-3, CanESM2, CMCC-CESM, CMCC-CM, CMCC-CMS, CNRM-CM5, CSIRO-Mk3-6-0, GFDL-CM3, GFDL-ESM2G, GFDL-ESM2M, HadGEM2-CC, inmcm4, IPSL-CM5A-LR, IPSL-CM5A-MR, IPSL-CM5B-LR, MIROC5, MIROC-ESM, MIROC-ESM-CHEM, MPI-ESM-LR, MPI-ESM-MR, MRI-CGCM3, MRI-ESM1,NorESM1-M, and the data have been created through probabilistic statistical downscaling methodologies, which is a further distinction of statistical downscaling method, and are defined as those that output a full probability density function (PDF) for each time step, instead of a unique value for each time step.

The main results of this study will be three ASHRAE-equivalent metrics, showing how the climate design conditions will be different between three time periods. By analyzing and comparing these three charts, we will show (i) how annual and monthly temperature and precipitation will change over Madison, WI in the 21^st century, (ii) what building design metrics are most sensitive to projected changes, (iii) how those sensitive metrics are impacted by climate changes (temperature and precipitation), (iv)and provide a best-available estimate of future climate impacts on building design metrics over Madison.