Infrared (IR) Shading as a Strategy to Mitigate Overheating in Traditional Buildings

In urban heat islands with sun-exposed roofs, the cooling potential of unfinished attics is often insufficient. Attics and the adjacent floor often overheat and do not cool sufficiently during tropical nights. Because of heritage-preservation requirements and limited structural reserve in historic roof constructions, it is often not possible to install heat-dissipating photovoltaic modules or add a superimposed cold-roof assembly above the existing roof skin. A possible solution is ‘infrared (IR) shading’, which uses interior IR-shading elements to shield long-wave radiation from the solar-heated roof skin. The research had two goals: (i) develop and evaluate lightweight IR-shading elements that can be reversibly mounted at rafter level on the attic side; and (ii) investigate how rafter-field ventilation can remove heat from the IR-shading elements.