Cumulative Multi-Day Effect of Ambient Temperature on Thermal Behaviour of Buildings with Different Thermal Masses

Abstract

In most studies, the effect of the thermal capacity of the building envelope on changes in internal temperatures is reduced to a 24 h period. During this period, daytime heat gains are balanced by nighttime heat losses. The maximum indoor temperature, the diurnal variation of the indoor temperature and the time lag between the occurrence of the maximum daily temperature determine the effect achieved. The aim of the article was to show that the effect of the thermal capacity of a building on the indoor temperature is not limited to 24 h but accumulates over a period of several days, mainly depending on the temperature and solar radiation history of the previous days. As a result, contrary to what some studies have suggested, the bedrooms of heavier buildings remained significantly colder at night during periods of prolonged high outdoor temperatures. The results obtained may fundamentally influence the perception of the effect of using the high thermal capacity of the building envelope to reduce high indoor temperatures in hot weather.