The Effect of Solar Reflectance, Infrared Emissivity, and Thermal Insulation of Roofs on the Annual Thermal Load of Single-family Households in México
Abstract
In Mexico, as a result of the Mexican climate and predominant construction techniques, a significant part of the heat flow between single-family houses and the environment occurs through the roof. Because of this, reducing the energy expenditure for air conditioning requires knowledge of the thermal properties of roofs, including the solar reflectance (SR) and infrared emissivity (IE) of the outer surfaces and the thermal conductivity of the bulk material. Here we present the result of TRNSYS simulations of a sample household, where we systematically vary SR, IE, and thermal insulation of the exposed rooftop. Our results show that the greatest reductions in annual thermal load occur in cities with warmer climate. Thermal insulation itself only becomes important when both of the other properties are inappropriate for the local climate.
Keywords
Cool roofs, Reflective/emissive coverings, Trnsys, Building simulation.