Evaluation of thermal comfort standards in office buildings of Chile: Thermal sensation and preference assessment

Abstract

Currently, there are few studies aimed at evaluating the indoor thermal comfort of specific contexts such as that of Chile, where national standards are based on international references and are not mandatory. For this research, a field study was conducted in 19 buildings in Chile: 10 in Concepción and 9 in Santiago. Thermal comfort surveys and simultaneous measurements were carried out to calculate users' comfort temperatures according to their thermal sensation and thermal preference. The comfort temperatures obtained are compared with the comfort ranges defined by national standards and differentiated by the modes of operation of the case studies: Heating Only (HT); Mixed Mode (MM); and Heating, Ventilated and Air Conditioned (HVAC). The results show that in general, occupants adapt themselves to the indoor operative temperatures, especially with regard to their thermal preference. The neutral temperatures range from 19.5 °C to 24.6 °C and the preferred temperatures range from 19.9 °C to 24.6 °C amongst all cases studied. With regard to the national thermal comfort standards, the Sustainable Building Certification system (CES), which is based on ASHRAE 55, and the Terms of Reference on Environmental Comfort and Energy Efficiency (TDRe), their adaptive method is applicable in HT and MM buildings when occupants have adaptive opportunities. The findings of the summer fieldwork in HVAC buildings do not match the steady-state method of ASHRAE 55 (0.5 Clo) since the neutral and preferred temperatures, as well as the operative temperatures, are below the range stipulated, although they do match the TDRe comfort range.