Determinants of Carbon Dioxide Exposure for Residents and Staff of Nursing Homes: A Field Monitoring Study in Spain

Abstract

Providing high air quality is crucial to the health and well-being of older people living in nursing homes. A measurement study was undertaken in 22 communal rooms of five nursing homes in Spain to investigate the effects of heating, ventilation, and air-conditioning (HVAC) systems, room characteristics, and occupant activities on the indoor air quality. The study included 196 periods of data collection (equivalent to 5282 measurements). To the authors’ knowledge, this is the first study of indoor air quality in Spanish nursing homes. The study found that mean CO₂ concentrations were consistently below established standards, although notable peaks were evident due to specific activities. Natural and cross ventilation had a clear role in maintaining CO₂ concentrations below recommended levels. The findings indicate that lower occupancy density may be required in rooms where high-CO₂-generating activities take place, such as gym–physiotherapy rooms. The results showed that the older residents and staff were both more thermally comfortable at higher CO₂ concentrations. This suggests that striking a balance between air quality and thermal comfort is necessary. The study provides useful insights for the design of ventilation systems and spatial layouts of nursing homes, which can achieve higher levels of indoor air quality and occupant well-being.