**Humid air** always contains dry air and steam. Once the saturation is exceeded water droplets and ice occur. The calculations presented are limited to relative saturation up to 100%. In good approximation dry air and steam can be regarded as ideal gases. The calculations are valid for humid air at ambient pressure and temperatures between 5 - 70 [°C].

- Enter volume flow of humid air.
**Mass flow of dry air is assumed to stay constant.**
- Enter temperatures of humid air. If state 2 remains undefined, temperature will be assumed to stay constant.
- Enter ambient pressures. If state 2 remains undefined, ambient pressure will be assumed to stay constant.
- Enter relative humidities. If state 2 remains undefined, mass flow of dry air and water steam will be assumed to stay constant.
Relative humidity of state 2 will be calculated. Exceeds relative humidity 100% water will be separated.

The dew point of a humid air is the temperature at which its realive humidity reaches 100%.
Relative humidity equals 100%, if the partial pressure of steam equals its saturation pressure.