To calculate the amount of water obtained from a cold plate below the dew point, consider factors like air flow (6000-7000 cfm), air temperature (22-30°C), relative humidity (50-80%), and the size of the plate. The plate material should ideally be aluminum or plastic to prevent corrosion, and it will operate just below the dew point to maximize water collection. The cooling coil's effectiveness and the energy removed from the air are crucial for determining water yield. A power requirement of approximately 50 kW is needed to achieve a dew point of 55°F for the specified air flow. The water will naturally collect and drip off the plates without the need for additional mechanisms like vibration.