Impact of Extreme Climates on Sustainable Cooling in Subtropical Buildings

Strategic Insights -

Research conducted at Hong Kong Polytechnic University has shed light on the effects of extreme weather conditions and climate change on the energy efficiency and carbon emissions of chiller systems in commercial buildings in subtropical climates. The study aimed to assess the impact of these conditions on energy usage, efficiency, and thermal comfort in a 40-story office building in subtropical Hong Kong. The research used EnergyPlus simulations to predict annual cooling loads, electricity consumption, and predicted mean votes across different zones in the building. The findings suggest that applying an ultra-efficient chiller system can lower annual electricity consumption by 12.16-13.37% and contribute to the 30-40% reduction target for carbon neutrality by 2050.

Key Takeaways:

  • The study used a least-square support vector regression based on historical data (1993-2023) to justify hot weather conditions and predict the impact of extreme weather years (EWY) and climate change forecasts for 2050 and 2080.
  • The results showed a minor increase in predicted peak cooling demand: 0.46% in the EWY, 0.40% in 2050, and 0.37% in 2080.
  • Thermal acceptability dropped by 2.00-18.13% in EWY, 0.41-15.78% in 2050, and 4.15-27.79% in 2080.
  • The research highlighted the importance of ultra-efficient chiller systems in mitigating rising peak and annual carbon emissions associated with extreme heat.
  • The study's findings have implications for climate change mitigation strategies and the development of sustainable cooling systems in subtropical climates.

Statistics:

  • 0.46% increase in predicted peak cooling demand in the EWY
  • 0.40% increase in predicted peak cooling demand in 2050
  • 0.37% increase in predicted peak cooling demand in 2080
  • 2.00-18.13% decrease in thermal acceptability in EWY
  • 0.41-15.78% decrease in thermal acceptability in 2050
  • 4.15-27.79% decrease in thermal acceptability in 2080
  • 12.16-13.37% reduction in annual electricity consumption with ultra-efficient chiller systems

Sources:

  • NewsRx, September 22, 2025
  • NewsRx, "New Findings from Hong Kong Polytechnic University in the Area of Sustainability Research Described (Impact of Extreme Climates On Sustainable Cooling: a Case Study of a Subtropical Office Building)", Global Warming Focus, p 380
  • Urban Climate, "Impact of Extreme Climates On Sustainable Cooling: a Case Study of a Subtropical Office Building", Elsevier, 2025;63.