Thermal insulation of building envelope toward zero energy design in hot-humid climate

The use of thermal insulation in the building envelope in hot and humid climate is investigated through computer simulation. A total of 1,944 parametric simulation runs were carried out for three different cities and climate zones in Brazil (Curitiba, Brasilia and Salvador), considering variation of window-to-wall ratio, SHGC of the glazing system, insulation thickness in exterior walls, type of walls, and internal load densities. The results have confirmed that the building envelope has more influence on cooling energy consumption for building models with low interior load densities. Thermal insulation of exterior walls has negative impact for Brazilian cold climate, increasing the energy consumption for cooling as avoid the internal heat dissipation to the exterior environment. But in hot climate the energy consumption for cooling can be decreased with thermal insulation of exterior walls. In this case, the energy savings for cooling achieved up to 3.3%. Thermal insulation of exterior walls revealed to be a good solution to reduce peak cooling loads for the three climates under analysis, with 7.8% of maximum cooling capacity saving for the hottest city.