The mass of the aeration dryers is measured after defined time intervals. The ambient air of the aeration dryers is kept at a constant high relative humidity during the test with an air humidifier. The following figure shows the loading curve of the three different aeration dryers. The test period is 50 days.
The effects of the hydrophobic membrane and the valves are clearly visible. The adsorbed water volume of the aeration dryer with holes is 10% of the dry mass at the end of the test. The hydrophobic membrane is responsible for a loading of 3.6 % after 50 test days. At 0.6 %, the aeration dryer with valves has the lowest loading after 50 test days.
As can be seen, the aeration dryer with the simple holes, has the largest slope. Its loading increases on average 0.2% per day. The slope of the aeration dryer with valves is lower by a factor of 22.