Vacuum Chamber Design

[LabTech09]

Greetings,

I have a vacuum chamber that was recently purchased to dry 96 strip well plates. After the maiden voyage, we have found significant problem. It doesn't seem to work. The chamber holds a constant (roughly) vacuum of about 1 Atmosphere, however after 16 hours of operation the relative humidity is still about 80%. We have a few other chambers that work well for this task and dry the plates completely in about 8 hours.

In the new chamber the port that the air is pulled from the chamber is located at the bottom center of the rear wall; on the older chambers the port is located on the upper rear of the side wall. Is it possible that the port being too low is preventing the moisture in the plates from leaving the wells?