Avoid moisture damage to walls caused by condensation. Calculate the Dew Point to determine the temperature at which condensation starts to form.
Dew Point: is the temperature to which air would have to cool (at constant pressure and constant water vapour content) in order to reach saturation.
Relative Humidity: a measure of the amount of moisture in the air. Technically speaking, it is the ratio of water vapour density (mass per unit volume) to saturation water vapour density.
Calculate the minimum surface temperature required to minimise the risk of condensation forming and to determine the maximum humidity before condensation will start to form at a given surface temperature.