This paper aims to understand and characterize occupant behaviour from a perspective of air conditioner (AC) usage. Therefore, it analyses data collected via a questionnaire applied throughout the Brazilian territory, which resulted in 3,259 valid answers explored by non-parametric statistical methods. The main results obtained were: (i) 89% of interviewed occupants prefer naturally ventilated environments at home; (ii) their preference impacts their behaviour, as those who prefer naturally ventilated environments tend to ventilate their house instead of turning on the air conditioner; (iii) climate and family income influence the availability of appliances, i.e. 93.2% of the high-income groups have at least one AC at home in extremely hot climates; (iv) there are groups with a tendency of high AC use, especially those who use AC often, also use it for a longer period of time; and (v) there is a significant difference between the setpoint temperature used in different climates; for instance, the lowest setpoint temperature is used in the hottest climate. This paper intends to contribute to a better understanding of occupants’ preferences and behavioural tendencies, especially in Brazilian residences and hot climates, while showing the influence of variables like family income and climate on such issues.