Removal of CO2, moisture and heat from ventilated suit under different pressures.

The relative equation among CO2 partial pressure in a helmet, ventilating flow, pressure and CO2 output, the relative equation among ventilating flow, pressure, humidity and rate of moisture removal, and the relative equation among ventilating flow, pressure, humidity and rate of heat removal were derived and analyzed. Its demonstrated that: ventilating mass flow for a constant CO2 partial pressure in the helmet decreases linearly as the pressure drops; the ventilating mass flow for removing a constant quantity of moisture decreases as pressure drops; the efficiency of heat removal increases as pressure drops due to the increase of moisture removal. The equations can be used for estimating ventilating flow in a ventilated suit and ventilating flow entering the helmet, and also for calculating automatically the quantities of moisture and heat removal by ventilation.