Thermal Comfort and Air Quality Control in UK Student Accommodation: Understanding the interactions between heating and ventilation systems, occupant experience, and indoor environmental conditions

The UK must radically curb greenhouse gas (GHG) emissions, whilst simultaneously adapting its infrastructure to cope with a warming climate. A vital area in which both of these issues must be addressed concurrently is in buildings. One building type that has seen rapid development in the UK is purpose built student accommodation (PBSA). However, some critical knowledge gaps exist regarding the operational performance of PBSA. Plugging these gaps will help practitioners understand how to deliver PBSA that are both lower energy in operation and more comfortable. A case study research design was used to investigate the in-use performance of two recently built PBSA developments by monitoring indoor environmental quality, radiator use, and window opening, alongside conducting surveys and semi-structured interviews with the building’s residents. The aim of the study was to investigate whether occupants could adequately control the indoor conditions, and also what effect their actions had on the internal environment and heating demand. The results showed that the occupants were generally satisfied with the thermal conditions in the heating season. However, thermal control was typically achieved by opening windows regularly, often for long periods, and frequently whilst the heating was on. Five behavioural causes of consistent winter window opening were identified. These were to prevent overheating, inadequate ventilation, poor understanding of the controls, lack of responsiveness of the heating system, and lack of financial implications. Heat losses via window opening were modelled and estimated to be as high as 44% of the total heat losses in certain rooms. In contrast, during summer, the majority of occupants could not control the thermal environment in their rooms. Overheating was widespread, severe and often prolonged. The surveys and interviews revealed that the vast majority of occupants were too hot. For many participants this was a major issue affecting their comfort, well-being and even academic performance. The study showed that design shortcomings, rather than occupant behaviour were primarily responsible for the conditions. Important lessons for the future design of PBSA are identified