Thermal performance and apparent temperature in school buildings: A case of cross-laminated timber (CLT) school development

Abstract

This paper examines the performance and apparent temperature in cross-laminated timber (CLT) school buildings. The research presents empirical data on the performance and provides the first set of data on apparent temperature in CLT school buildings. The development is in the New England area of the Northeast of the US. The investigation was conducted in the summertime. The principal aim of the investigation is to evaluate the performance, occupants’ comfort, apparent temperature, and other thermal indices concurrently in CLT school buildings. The research intends to understand if occupants of CLT school buildings are susceptible to thermal stress in summer and assess whether apparent temperatures are consistent with sensation. The study also discusses other indices, practical implications, and applications of the outcomes. To achieve the research aim, the study considered the field measurements of variables. Occupants’ comfort is accessed using the PMV and adaptive methods of various comfort standards. During the survey, the development was occupied from 8am-6pm and partly operated from 7pm-7am. The mean temperatures during the occupied and non-occupied periods varied from 22.1°C-22.4°C. The overall RH was 59.2%. The PMV range and sensation showed the occupants were comfortable. Approximately 80% of the users were satisfied with the thermal environment. The temperatures were within the acceptable bands of ASHRAE-55, CIBSE TM52, and EN16798-1 thermal comfort models. The results showed that the apparent temperatures are consistent with the outcomes of the sensation at different periods. The mean indices ranged from 18.8°C-23.5°C. The study recommends that further research should be conducted on occupants’ comfort and heat indices in school buildings during the first few hours of occupation to understand changes that occupants can make to remove unwanted heat from the thermal environment. The study also recommends that various designers should consider heat stress analyses along with thermal comfort assessment at the design phase to determine possible interventions to improve the thermal environment of schools and other buildings.