Conforto, percepção e reação de trabalhadores ao ambiente térmico em escritórios condicionados artificialmente no contexto do clima quente e úmido

Abstract

Environmental comfort and quality are among the necessary requirements to promote workers health, safety and productivity. Within this context, we can observe nowadays that many workplaces, specially in urban areas, have increased the use of air conditioning systems in order to assure thermal comfort, regardless of the external environment’s climate conditions. The question posed by this fact approaches the standards adopted by the adjustment of the air conditioning system and the addressing of the workers’ comfort needs in a city with a warm and humid climate. This research is a case study of an institutional building which office spaces’ thermal control is achieved by the exclusive use of an air conditioning system. The building is located in the city of João Pessoa – PB. The environment variables – air temperature, relative humidity and airflow speed – of 136 workstations were monitored throughout an entire month in 2016, while simultaneous to the technical measurements, questionnaires were applied to their respective users regarding the votes of thermal feeling and preference. In addition, we explored the adaptation actions of the stations’ occupants towards their own adequacy to the thermal environment conditions sensed in their workspace. Results have showed that whereas the average operative temperature was 22,81°C, the occupants’ votes indicated as thermoneutral temperature the interval between 22,5°C and 23,5°C, demonstrating that although the air conditioning system is being adopted to reduce heat discomfort, it actually entails discomfort by cold. Also, however the system intents to reach a uniformity of thermal conditions in the internal environment, we could register fluctuations in these conditions in the individual workstations, as temperatures varied within a range of 5,46°C. We highlight in the study the fact that occupants sought to modify their environment and adjust whatever they thought necessary to compensate least favorable thermal conditions, adopting primarily the most accessible actions bound to personal status, specially clothing adaptations. It was also verified the statistical relevance of the association between ‘satisfaction with temperature’ votes and ‘adaptations actions’ related to the clothing (addition of more layers of clothing and the use of lighter clothes), whose results of p-value < 0,05 = 0,000. Mathematical model with the predictors 'typical thermal sensation', 'gender' and 'satisfaction with temperature' explain 46% of the variation of 'use more layers of clothing' action.