The interplay of a warming climate and socio-demographic transformations will increase global heat exposure. Assessing future use and impacts of energy-intensive appliances for indoor thermal adaptation is therefore a crucial policy goal. Here we train statistical models on multi-country household survey data (n = 480,555) to generate global gridded projections of residential air-conditioning (AC) uptake and use. Our results indicate that the share of households owning AC could grow from 26% to a scenario median of 38% by 2050, implying a doubling of residential AC electricity consumption, to 925 TWh/yr. This growth will be highly unequal both within and across countries and income groups, with significant regressive impacts. Up to 4.5 billion heat-exposed people may lack AC access in 2050. Outcomes will largely depend on socio-economic development and climate change pathways. Our gridded projections can support the modelling of the impacts of residential AC on decarbonization pathways and health outcomes.