Impacts of air conditioning use on thermal perception in open spaces in downtown Rio de Janeiro

Abstract

Studies on thermal perception in outdoor spaces are crucial for climate-responsive urban planning. This paper evaluates the thermal perception of users in outdoor spaces in downtown Rio de Janeiro, with the aim of analysing the impact of long-term use of air-conditioning on thermal sensation and thermal preference votes. Thermal votes from structured interviews are compared to standard thermal indices for outdoor spaces (PET and UTCI), by grouping responses in terms of reported air-conditioning usage. The monitoring campaigns were carried out during summer periods between 2012 and 2015. The semi-experimental set-up involved the permanence of equipment and researchers at a single point per campaign during a period of time spanning 10am to 3pm. A Davis Vantage Pro2 weather station was used for monitoring along with the administration of standard comfort questionnaires as in ISO 10551, with additional questions as regards air-conditioning usage at work and/or at home. Results suggest that the frequent usage of air-conditioning affects thermal perception and is a confounding factor in the definition of comfort limits for the evaluated indices PET and UTCI.

Keywords:
Urban climate; Thermal history; Thermal perception in outdoor spaces; Thermal comfort indices; Air-conditioning use