Gas humidification refers to the addition of water vapor to a gas flow to create a specific relative (RH) or absolute humidity. Relative humidity is % of water vapor present of the maximum possible (which depends on the specific conditons: temperature and pressure). Absolute humidity relates to the number of atoms, and is independent of reference conditions.
What is Gas Humidification Used For?
Gas humidification replicates real life environments, be that for research, cultivation or calibration. It is routinely used to replicate exhaust, emissions, ambient conditions or even human breath, essentially enabling users to add specific RH levels to a blend of gases to simulate an extremely wide variety of actual conditions or other cases where gas samples contain humidity.
Methods of Gas Humidification
- Bubbler is a type of gas humidification is through a bubbler. This system allows dry gases to "bubble" through water at set temperature. This produces very small bubbles of gas, increasing the contact surface which offers maximum humidity to be picked up by the bubbles. Bubblers can be cheap and simple solution, but are suitable only for low humidities, near atmospheric pressures, low flows, and non-toxic gases. The RH% an absolute humidity can be calculated when pressure and temperature is known.
- Ultrasonic and piezoelectric evaporators use kinetic energy is used to break the surface tension and disperse the fluid into very small droplets, thus increasing the surface area of the fluid making it evaporate fast. Not suitable for large amount of fluid.
- High pressure fluid is pushed through a nozzle with many tiny holes in order to break the fluid into smaller droplets.
- Heat energy is used to boil off the liqiud. This is simple and robust method that is suitable for anything from tiny to huge amounts of fluid, even at elevated pressures.
