Air conditioning, power failure, and health protection in UK residential care buildings

Recent monitoring of indoor temperatures in residential care buildings in the UK has demonstrated that overheating is widespread according to CIBSE standard criteria. Given the warming climate and increasing frequency of heatwaves, overheating is likely to increase in future. Updates to the building regulations require new residential buildings to meet these criteria by passive methods if possible and by air conditioning if not. Existing buildings have air conditioning in few areas: usually treatment rooms and sometimes common sitting areas. Questions remain over how best to reduce the health impact of overheating in these settings.

We explore the resilience implications of increasing use of air conditioning in these buildings. If buildings are reliant on air conditioning, then continuous power supply is required. We present results from a building energy model of care home buildings during a heatwave. The extreme heatwave of July 2022 was simulated. Stoppage of the cooling system was simulated as occurring during the peak of the heatwave, which in reality could be caused by a power failure or failure of the system itself. We demonstrate that under certain conditions the indoor temperature can increase very rapidly once cooling fails, reaching unacceptable levels in minutes. There are large variations between buildings and between rooms in buildings, depending on construction and orientation. We consider what building modifications and behavioural responses could reduce the impact of this on residents.

Adapting care homes to higher temperatures will be of increasing importance, and this research will help to identify what strategies are most effective and resilient.