Thermal Environment Perceptions from a Longitudinal Study of Indoor Temperature Profiles in Inpatient Wards

• Published in: Buildings (Basel) 2020-08, Vol.10 (8), p.1-18
• Main Authors: Alotaibi, Badr S, Lo, Stephen
• Format: Article
• Language: English
• Subjects: Air conditioners; Air temperature; Cardiology; Cooling; cooling strategy; Cooling systems; Correlation analysis; Demography; Design; Energy costs; Energy use; Heating; Heating, cooling and ventilation; Hospital units; Hospitals; Hot climates; Humidity; HVAC; HVAC equipment; Indoor air quality; Indoor environments; indoor temperature profile; Longitudinal studies; longitudinal study; Nurses; Patients; Perceptions; Preferences; Relative humidity; set-point range; Temperature; Temperature perception; Temperature profiles; thermal environment; Thermal environments; Ventilation; Ventilators
• ISSN: 2075-5309; 2075-5309
• DOI: 10.3390/buildings10080136

Inpatient wards in general have cooling systems with a “one-size-fits-all” approach, driven by a fixed set-point temperature (21–24 °C) that is flexible to lower limits down to 18 °C or less. This approach does not consider patients’ temperature demands, which vary due to thermo-physiology caused by medical conditions, and mixed demographics. It also causes additional cooling demands in hot climates that are infrequently utilized by patients, who tend to adopt warmer internal set temperatures. Thus, this research examined the indoor temperature profiles (distribution of shape) in patient rooms in fully air-conditioned inpatient wards over an extended period of time. During four months of summer, longitudinal monitoring of internal temperature and relative humidity was carried out in 18 patient rooms in the surgical, medical, cardiology, and oncology wards of two hospitals in Saudi Arabia. In parallel, 522 patients were surveyed to capture common subjective thermal indices. The findings revealed that the most frequently preferred temperature (peaks) varied significantly between wards; peaks (modes) were 20.1–21.8 °C in cardiology; 22.2–23.9 °C in the surgical ward; warmer 24.8–25.3 °C in medical ward; and 25.3–26.8 °C in oncology. Surveys also showed that patients were not satisfied with the indoor environment in both hospitals. Given the significant variance in temperature profiles between wards and patient dissatisfaction with the indoor environment, these results suggest that more appropriately designed zoned cooling strategies are needed in hospitals as per the nature of each ward. Besides its implications for benchmarking the HVAC system, this approach will substantially reduce energy loads and operational costs in hot-climate hospitals if patients desire warmer conditions than the set conditions provided by system.