The number of people in a battery dry room:
The number of people in the dry room will determine the moisture load to be removed by the drying system. Expected water evaporation from each worker will be part of the technical specifications for the dry room facilities and will have a linear impact on the required minimum airflow.
The required dewpoint inside a battery dry room:
The dewpoint requirements, however, will have an exponential impact on the minimum airflow. The minimum required airflow can be calculated as:
in which the moisture load is typically 120 g/h multiplied by the number of workers in the room and the air density is 1,2 kg/m3. The desired humidity must be stated in absolute humidity, i.e. g/kg.
The absolute humidity, X [g/kg] for different dewpoints are:
- -40°C = 0,079 g/kg
- -50°C = 0,0243 g/kg
- -60°C = 0,0067g/kg
The below examples are theoretical limits when assuming that the supply air will be at zero moisture content. As this will never be the case in real life. Minimum airflow rates will always be approx. 10-20% higher than the theoretical values.
Example 1 - What is the minimum required airflow for 1 person at -40°C dwpt.?
Example 2 - What is the minimum required airflow for 1 person at -60°C dwpt.?