Global climate change has significant impact on the energy demands of buildings. Studies have found that global warming would cause a decrease in heating requirements and an increase in cooling requirements. In Florida, cooling demands are major concerns in order to maintain the indoor comfort standards and to respond to the energy efficiency requirements from the government (Jiang, et al., 2018; Kwok and Rajkovich, 2010). According to the reports of US Energy Information Administration, commercial buildings in Florida account for about 24% of total energy in 2015. Research conducted by Jiang (2018) indicated the cooling demand will increase in the coming decades at various rates ranging between 26% and 80% in Florida, depending on the commercial building types and locations in Florida.
Although studies of the impact of climate change on the energy consumption of various building types have been conducted in many countries, few of the studies propose mitigation of the impact on energy demands of the buildings. The mitigation of global climate change's impact on buildings challenges architects, engineers, and builders to design and construct sustainable and energy-efficient buildings and facilities. The study investigates the current and future cooling demands of four main commercial buildings in eight selected cities of nine climate zones of Florida, by accommodating the thermal resistance features of wall and roofing systems.
The study shows that the cooling demands are reduced at various rates in all studied building types and in all climate zones by changing the thermal resistances of roofing systems from R-12/14/16 to R-19/21 and wall systems from R-13 to R-19/21. Among the studied commercial building types, secondary schools have the highest cooling demands per unit area (75-110 kWh/m2) while apartments have the lowest cooling demands (30- 60 kWh/m2). The cooling demands of apartment buildings can be reduced as much as 5% by changing the wall and roofing thermal resistance to R-21. The cooling demands of secondary schools are least sensitive to the change of thermal resistance: the reduction rate is as much as 3.5%. Since buildings have more exterior wall area than roof areas of the buildings, the cooling demands are reduced more by increasing the thermal resistances of wall systems in all studied building types.