Assessment of outdoor design conditions on the energy performance of cooling systems in future climate scenarios - A case study over three cities of Texas, Unites States

Abstract

The excessive use of energy in buildings due to increased populations and economic development leads to more greenhouse gas emissions, which affect climate change and global warming. Changes in prevailing outdoor weather conditions significantly affect the energy systems of buildings through increased cooling and decreased heating. In this paper, 30 years of data of dry and wet bulb temperatures (1990–2020) with a time interval of 3 h were considered in order to estimate the climatic outdoor design conditions in the cities of Dallas–Fort Worth, Houston, and San Antonio in the state of Texas. The results suggest that the dry bulb temperature (DBT) had significantly higher increases in Dallas–Fort Worth (2.37 ◦C) than the wet bulb temperature (WBT) in Houston (4.1 ◦C) during the study period. Furthermore, this study analyzed the effects of climate change on cooling degree hours (CDH) and heating degree hours (HDH) and the results suggest the most significant drop in HDH in Dallas–Fort Worth with a maximum CDH fluctuation as compared to other two cities. The effect of climate change on the performance of cooling systems is also investigated in this study via direct evaporative coolers (DECs) and direct-indirect evaporative coolers (IDEC), which do not perform well in the selected cities. In contrast, absorption system (Abs) and vapor compression (VC) systems show an increase in the number of additional loads. The second part of this study is related to the future projection using the ARIMA model, which suggests that DBT would rise significantly in Houston (from 37.18 ◦C to 37.56 ◦C) and Dallas–Fort Worth (39.1 ◦C to 39.57 ◦C) while diminishing in San Antonio (from 34.81 ◦C to 33.95 ◦C) from 2020 to 2030. In contrast, WBT will experience an upward trend in Houston (from 36.06 ◦C to 37.71 ◦C) and Dallas–Fort Worth (from 31.32 ◦C to 31.38 ◦C) and a downward trend in San Antonio (from 32.43 ◦C to 31.97 ◦C) during 2020–2030. Additionally, the future performance prediction of Abs and VC systems is also performed, which reveals that the amount of additional load required is significantly higher in 2030 compared to 2020 and is more prominent in Houston. Conversely, amount of additional load required for cooling systems in San Antonio shows a decreasing trend in 2030.