The relationship between indoor and outdoor temperature in warm and cool seasons in houses in Brisbane, Australia

The study aimed to identify diurnal indoor temperature patterns and quantify the impact of outdoor on indoor temperature as well as of other modifying factors. Indoor and outdoor temperatures of 77 houses in Brisbane, Australia were monitored with temperature sensors for one year (May 2017–2018). A linear mixed effect model predicted that on average, a 1 °C increase in outdoor temperature resulted in a 0.41 °C increase in indoor temperature during both the cool and warm seasons. The age of the house, building material, roof material and insulation had a moderate influence on indoor temperature. Queenslander houses (a stand-alone timber structure mounted on stumps with an extensive veranda) were, in general, cooler (0.5 °C cooler in winter) and reactive (meaning, having a strong association with the outdoor temperature), while slab-on-ground houses were, in general, warmer (0.3 °C) and stable (meaning, having less association with the outdoor temperature). From the indoor temperature patterns identified for the heated and cooled houses it was concluded that in this climate, heating and cooling is seldom done for 24 h. This quantitative information is crucial for understanding the influence of temperature on human health and household energy consumption at the time when climate change mitigation approaches are being discussed.