Monitoring and modelling the risk of summertime overheating and passive solutions to avoid active cooling in London care homes

Rajat Gupta,Alastair Howard,Mike Davies,Anna Mavrogianni,Ioanna Tsoulou,Nishesh Jain,Eleni Oikonomou,Paul Wilkinson

doi:10.1016/j.enbuild.2021.111418

Abstract

Summertime overheating in care settings has been identified as a key risk and research priority for the health and social care system. This paper examines the current and future risk of summertime overheating in two London-based care homes occupying modern and older buildings. Continuous monitoring of outdoor and indoor temperature in bedrooms, communal areas and offices in summer 2019 helped to establish the prevalence and intensity of overheating. Dynamic thermal simulation (EnergyPlusV8.9) of the two care settings assessed the potential for avoiding active cooling in future climate using passive solutions. In both care settings, indoor temperatures were observed to exceed 30 °C during daytime hours, significantly higher than the recommended 26 °C threshold of Public Health England. Although severity of overheating was lower in the older building, overheating was found to be prevalent and prolonged across both care settings with bedroom temperatures higher than lounges especially at night. Thermal simulation analysis showed that, with regards to temperature reduction and cooling load, nighttime ventilation was the single most effective passive solution for both buildings for the current climate, while a combination of night ventilation, external shading and high-albedo external walls was the most effective package solution. By the 2080s, air-conditioning was the most effective solution for reducing temperature, but also had the highest cooling load, highlighting the importance of balancing passive with active measures to improve thermal comfort and reduce cooling loads.

Highlights

In 2019 about 9% of the world’s population was over 65 years old
The research presented in this paper aims to deepen understanding about the prevalence and severity of overheating within newer and older care home buildings in London
Guided by the definitions used for overheating analysis in CIBSE Guide A, TM52 and TM59, occupied hours were defined as 09:00– 18:00 in the offices and 08:00–21:00 in the lounges

Summary

Introduction

In 2019 about 9% of the world’s population was over 65 years old. By 2050 this is projected to be 16% [51]. The proportion of 85 + year olds in the UK is predicted to increase by 36% between 2015 and 2025 [11]. All of these predictions indicate that the UK care home population – 410,000 in 2017 [11]– will increase significantly, with demand on state and privately funded care home services increasing. In parallel with the aging population, climate predictions indicate that temperatures will continue to rise. This will mean an increase in the frequency and severity of heatwaves. Research has shown that heatwave periods coincide with increased levels of mortality, within the elderly population [29]

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