This major research paper explores the sensory and spatial characteristics of installation art that contribute to the manifestation and dominant presence of the un-calm. The “un-calm” challenges the traditional perception that art viewing is a calm experience. The term is used in this paper with reference to feelings of unease and discomfort that emerge in the process of viewing installations that incorporate difficult and unexpected content. Two case studies will be analyzed based on their spatial and sensory properties to show how they enact un-calm. The first, Rebecca Belmore’s Fountain (2005/2018), confronts viewers with a dark interior and noisy waterfall, facilitating a confrontation with symbols of conquest. The second, Sarah Anne Johnson’s Hospital Hallway (2015), takes place inside an octagonal enclosure replicating a 1950s psychiatric hospital to convey the trauma of medical mistreatment. Both case studies will be guided by an examination of the development of affect, and the role it plays in making installation art distinctive. These case studies will also reveal the causes of the affect of the un-calm, and where the un-calm is situated within current social and cultural norms. By examining the sensory and spatial causes of the un-calm, this MRP uncovers how specific environments can affect the emotional state of audiences, and positions the un-calm in a broader context.