A study of thermal comfort in naturally ventilated churches in a Mediterranean climate

•Baroque churches are thermally comfortable in summer, spring and autumn according to EN 16,798–1.•Contemporary churches prove to be thermally uncomfortable in summer and winter according to EN 16,798–1.•Low thermal mass result in high indoor temperature and vice versa.•Low thermal mass result in high indoor temperature fluctuations and vice versa. This paper investigates the status quo of the indoor comfort temperatures of a number of reference churches in Malta, ranging from large and small Baroque buildings to more contemporary buildings, throughout the twelve-month monitoring period of 2018. This is carried out as a first step towards understanding and evaluating the extent of comfort issues in these buildings. It was found that the thermal mass of buildings plays a very important role in controlling indoor temperature in these free running structures. The Baroque churches proved to have an overall high thermal mass when compared to the mid-20th century neoRomanesque style architecture, and late 20th century (post Vatican Council II style) contemporary architecture, with the result of a steadier indoor temperature in Baroque churches and higher fluctuations in temperature for the more recent architectural styles. This behaviour is mainly attributed to the lack of overall thermal mass of the building and higher solar gains through glazed elements, providing minimal "inertia" against external temperature fluctuations. This is evidenced by the results obtained in this study, which give a sound indication of the thermal comfort in naturally ventilated churches in a Mediterranean climate