Examining respiratory comfort in vernacular and conventional buildings

The study examines the role of air temperature and humidity on heat and moisture exchanges in the human respiratory tract. A human respiratory tract model was built to solve for heat and mass balance under varying indoor temperature (Ti)and relative humidity (RHi)values. Ti and RHi from on-field measurements from Vernacular (Adobe) and Conventional (Brick/RCC) buildings were used as input parameters to this model for computation of temperature (Ta in °C) water vapor concentration (Ca in mg/l) at different segments of the respiratory tract. Results indicate that at the same temperature, relative humidity has a significant bearing on respiratory air conditioning. Also, at a given length of the respiratory tract, the percentage of heating and humidification achieved was higher in vernacular room conditions compared to the conventional room. Excess water vapor loss from the mucus layer in the deeper airway conduits restricts mucociliary clearance causing respiratory difficulties, predominantly in cold regions. Comfortable respiration is an important indicator of health and productivity; however, it is not presently incorporated for indoor comfort evaluation. Insights from the study can lead to recommendations for material selection for the design of comfortable, healthy indoor environments.