The approximate amount of drainage of the precision air conditioner (TCU/ECU) can be calculated using the following formula.

Calculation formula for drainage volume

Drainage volume [kg/h] = Air volume [m³/min] x 60 x Absolute humidity difference [kg/kg(DA)] x Air density [1.2kg(DA)/m³]
*For temperature and humidity control type air conditioners, surplus humidifying water is drained separately.

The absolute humidity difference is the difference between the absolute humidity of the intake air of the air conditioner and the absolute humidity of the discharge air of the air conditioner.

For example, in case of cooling and dehumidifying 27℃ 70% air to 23℃ 30%,

absolute humidity of air at 27℃ 70%: 0.0157kg/kg(DA)
absolute humidity of air at 23℃ 30%: 0.0052kg/kg(DA)

therefore, the absolute humidity difference is "0.0157kg/kg(DA) - 0.0052kg/kg(DA) = 0.0105kg/kg(DA)".