SIPHON FEED METHOD
In the Siphon feed setup (shown in Figure 1), temperature at which the air will be fully saturated (“dew point”) must be determined. The humidifier must be heated or insulated to this temperature and kept constant. A reservoir of de-ionized water is pulled through to fill the shell side and cap off at the outlet. A positive pressure sample gas is pushed through the inner tubes and is humidified.
CIRCULATION FEED METHOD
The circulation method (shown in Figure 2) requires heated water to be continuously circulated. The flow with greater pressure needs to be flowing inside the tubes to prevent tubing collapse.