Selection should be based on the total cubic volume of the warehouse, the desired RH (Relative Humidity) level, and existing temperature. For vast warehouses, high-airflow models like the Trotec TTK 650 S are preferred to ensure air reaches every corner. We recommend multiplying 6 to your total cubic volume of warehouse and the answer iwill tell you what your minimum airflow in a portable professional dehumidifier should be in order to reduce humidity effectively.
For example: If a warehouse has a volume of 200 cubic meters, then multiply by 6 and the answer is 1200 cubic meters. So your ideal portable professional should be 1200 cubic meters/hour airflow.
Now this is subject to warehouse dimensions as well. In some cases, you can base your selection multiplying 3 or 4 your room volume but without proper knowledge of infiltration points, moisture ingress etc - times 6 provides a better selection covering for these factors if any.