Sensitivity of thermo-physical parameters of RTQ-R: analysis according to the prescriptive method
Paper (in Portuguese)
The discussion about sustainability and energy efficiency in buildings increased due to the late concerns about energy and environmental issues. The Technical Quality Requirements for Energy Efficiency Level of Residential Buildings (RTQ-R) was released in Brazil in 2010. The RTQ-R specifies the technical requirements and methods for rating the energy efficiency level of residential buildings to obtain the National Energy Conservation Label of the Brazilian Labeling Program. This study aims to analyze the sensitivity of cooling degree hours (CDH) and relative consumption for heating (RCH) of the equations used in the prescriptive method of RTQ-R assessment to understand the weight that each variable has on the final label. The calculation of CDH and RCH is based on eight and four equations, respectively, which 36 parameters are multiplied and added at different ratios. There are equations corresponding to each of eight Brazilian Bioclimatic Zones. The analysis was performed using the software Simlab 2.2., developed for sensitivity analysis by Monte Carlo method. The variables used in the RTQ-R were selected using the Latin Hypercube Sampling. The sensitivity analysis was based on Regression analysis using Partial Correlation Coefficients (CCP). The amount of PCC may be positive or negative; it refers to a relation directly and inversely between dependent and independent variable, respectively. The results show that the parameter that presented the greatest influence on CDH are area of east openings and wall absorptance with positive influence and area of north and south openings with negative influence. As for RCH, the total sum of the area of exterior walls stands out with a positive impact and areas of openings with a negative impact. So, by verifying the relevance of variables, the study contributes to future improvements on labeling and emphasizes the parameters that should not be ignored during the development of architectural designs.