Experimental investigation and theoretical analysis of the human comfort prediction model in a confined living space

We investigated the fitting point at which a reasonable level of comfort could be ensured for people in a refuge chamber as well as the longest amount of time they could comfortably be in the chamber before being rescued. Using theoretical analysis and experimental investigation, we developed human comfort prediction models, including a single environmental factor model and a multiple environmental factor model. The models considered four key factors: oxygen volume fraction, carbon dioxide volume fraction, environmental temperature, and humidity. We modified and applied the predicted mean vote grade method to analyze one group of data with 169 data points of human comfort with single and multiple environmental factors. A large number of human comfort experiments were implemented to obtain human comfort data and verify the results of our theoretical calculations. We analyzed and calculated the recommended tolerance limits of the four factors for the rescue subjects to survive to allocate the limited resources and reduce energy consumption to prolong the survival time of the subjects to wait for rescue. The living conditions in a refuge chamber should be controlled to the point at which the oxygen volume fraction is at 18-22.7%, the carbon dioxide volume fraction is less than 1%, the temperature is less than 35 °C, and the humidity is less than 80%. We obtained the relationship between the multiple-factor comfort model and single-factor comfort model. We found that the order of the weight coefficients is oxygen  >  temperature and humidity  >  carbon dioxide.