Simulating indoor air quality in London hospitals

a building-based bottom-up method

Abstract

Healthcare premises are energy-intensive buildings, and their operation and performance are critical to healthcare delivery and the protection of patients. A key step towards ensuring people’s wellbeing and facilitating recovery is establishing the distributions of indoor air pollutants and temperature, and associated exposures in hospitals. Microenvironment pollutant concentrations are determined by the generation of indoor sources of pollution and the penetration of outdoor air to the indoors. In hospitals, the conditions for air pollution are typically highly controlled to deliver clean environments; however, building ventilation systems may still be subject to harsh external environments that impact on indoor environmental conditions. The aim of this study is to enhance understanding of how building operations and energy efficiency improvements will impact indoor hospital environments whilst reducing potential harmful pollutant exposures and energy demand. To achieve this, the ventilation conditions and corresponding PM2.5 penetration of London hospitals were simulated. The baseline data of building stock physics (building types, construction periods, floor levels, room functions, total floor area and energy performance ratings) for hospitals were aggregated from the building typologies and room functions of the London 3DStock model to analyse the effect of built configurations on air ventilation and pollutant transfer using the CONTAM tool. The simulation results show that recently built or retrofitted hospital buildings are more airtight and energyefficient but also need to carefully maintain intentional ventilation and filtration to ensure adequate air quality conditions to prevent the ingress of outdoor-sourced air pollutants. The simulations also show that COVID operating procedures may greatly increase airflow and a corresponding need for additional air filtration to meet guidance on pollution levels.