A temperature drop of 10° C / 18° F is not unusual, at the expense of some water and very little electric power. High-pressure humidification is the most energy efficient method found today. Only very little electric power is required to boost the water to a pressure of 70 bar. Eg 300 litres/hour (1.3 gpm) system only requires approximately 1000W electric power. When comparing high-pressure humidification to other methods, the more significant portion of energy costs to provide the absorption heat is often overlooked or not properly taken into consideration. The high-pressure principle works adiabatically, which means that no heat is added to the air to evaporate water. Consequently, the necessary absorption heat (2250 J/g) to transfer the water from liquid to gas is obtained from the air being humidified. The evaporative process is following the line of constant enthalpy in the hx-diagram (psychometric charts), resulting in a quite significant drop in air temperature after the absorption.