Consider equation [1.6-19] for relative humidity: where Pi indicates the partial pressure of water vapor and Pi* indicates the maximum vapor pressure of water at that temperature. At 25°C the maximum...

Consider equation [1.6-19] for relative humidity:

where Pi indicates the partial pressure of water vapor and Pi* indicates the maximum vapor pressure of water at that temperature. At 25°C the maximum vapor pressure of water is 0.0312 atm. During respiration, incoming air and water are warmed to 37°C in the nasal cavity and throat.

(a) Calculate the heat lost by the body during one hour of breathing air at 25°C and 10% relative humidity. Tidal volume of the lungs is 500 mL. Assume a breathing rate of 15 breaths per minute.

(b) Calculate the heat lost by the body during one hour of breathing air at 25°C and 90% relative humidity. Compare the results with part (a).