Assessment of thermal comfort of non-airconditioned in-patient hospital wards in dhaka during warm humid periods

Abstract

Thermal comfort is an important factor for creating a comfortable indoor environment and ensuring good health for the occupants of a tropical country like Bangladesh, where most of the in-patient hospital wards are highly dependent on natural resources for lighting and ventilation. Unlike healthy populations, the thermal comfort requirements of patients are quite variable which has not been studied in the context of Bangladesh yet, especially during warm humid periods. This research aimed to understand the effect of indoor thermal condition on patient’s perception, thermal sensation and thermal comfort level in non-air conditioned in-patient wards of the case study hospital. It also tried to identify ‘Neutral’ and ‘Preferred’ air temperature and relative humidity of occupants in the studied context. 400 data were collected from a combination of qualitative and quantitative methods; objective measurement of the environmental parameters (air temperature, relative humidity and air velocity) were collected with proper instruments and subjective assessment of questionnaire survey were conducted on 200 adult patients of Medicine and Surgery wards during warm humid periods. Through statistical methods patient’s comfort range for this period of the year were identified, which was 29.46 - 31.46ºC and 77.4-83%. The ‘neutral’ temperature and relative humidity of patients were identified as 30.45OC and 80.3% respectively whereas the ‘preferred’ air temperature and relative humidity were 30.26OCand 79.8%, which are much higher than the international standard but complied with the previous findings in the context of Bangladesh. Although more than 90% patients have voted their existing condition within acceptable range of comfort, 54.75% of them voted their thermal condition as ‘not comfortable’. So, more comprehensive investigation is required following the methodology adapted in this research, to establish the contextual requirements of thermal condition in non-air-conditioned In-patient wards of Hospitals during warm humid periods for Dhaka that can lead to formation of local design guidelines.