Uso do PMV para avaliação do conforto térmico em edifício de escritório tipo plano aberto e sua viabilidade de aplicação em clima quente e úmido

Abstract

Offices are often long-stay places framed as moderate thermal environments. Over the years the layout and physical configuration of these spaces have evolved due to several factors such as cost reduction and the expansion of communication processes between people. The development of air conditioning and refrigeration systems allowed the adaptation of these environments to an increasing number of occupants so that there were no damages related to thermal comfort. Although the use of air conditioners has been increasing in office buildings, there are few references that guide the design of environments that opt for this cooling alternative; the existing ones do not take into account the effects on the thermal comfort of the occupants according to the system listed for the building. The only normative references that discuss thermal comfort in these environments are the NR-17 - Ergonomics and part 2 of ABNT NBR 16401: 2008, which currently has a revision (ABNT CB-55: 2016), based on the proposed text by the American Standard ANSI / ASHRAE STANDARD - 55, with the purpose of integration to the Brazilian Standard of Thermal Comfort. In this sense, this work aimed to analyze the feasibility of the use of PMV, which is included in the proposal for ABNT CB-55: 2016, based on a field study in an office environment located at the Rectory of the Federal Institute of Technological Education of Alagoas, Maceió. The methodological procedures included the collection of internal environmental variables (air temperature, air velocity, globe temperature and relative air humidity) simultaneously with the application of questionnaires referring to occupants habits; anthropometric characteristics; acceptability, preference and thermal sensation, as well as issues related to the preference of the occupants for air conditioning and refrigeration systems. The data resulting from the measurements were calculated from the analytical method indicated by the proposal for ABNT CB-55: 2016 and evaluated based on the limit stipulated as comfortable by the Standard (PMV between +/- 0.50). The results showed that, according to the parameters indicated in the norms for the evaluation of conditioned environments, there was a certain imprecision in the use of the limits proposed by the Standard regarding the estimation of the sensation of heat and cold of the occupants, in the situation in which the experiment was performed. It was also evidenced that the sensations and thermal preferences reported by the occupants are influenced by the arrangement of the refrigeration system used.