Self regenerating desiccant for water management in external aircraft electronics

A common concern with electronics packaging is water condensation. The desire to use inexpensive non-hermetically sealed components drives us towards eliminating condensation on the electronics components. When the hardware is to be located outside the pressurized compartment on an aircraft, the widely varying environments aggravate the water concern. Several options were evaluated for their potential to eliminate condensation in an electronics enclosure when exposed to such environments. Venting the enclosure through a desiccant was shown to eliminate condensation. Further, the desiccant was shown to be self-regenerating due to the ascent/descent cycles. This paper presents the predicted performance of a desiccated system along with demonstration test data used to validate the analytical evaluation. Analysis and test results show that the desiccant system continuously and passively maintains a very low humidity.