In the Isothermal humidification process, the temperature of the air remains constant. Steam humidifiers increase the moisture content of the air without adding any heat. There is only a marginal increase in the air temperature due to the sensible heat gain from the steam distributor pipe(s).

Process steam or boiler steam is not suitable for humidification as boiler feed water has added chemicals such as corrosion inhibitors or chelating agents. Also, boiler steam is supplied through mild steel piping and can carry rust particles.

For HVAC and process applications, Condair offers humidifiers that generate clean steam using electric heaters (for smaller duties) and/or boiler steam as an energy source.