Desiccant-based and desiccant-assisted air-conditioning systems are currently emerging from a 50-year industrial heritage and expanding into commercial applications. Engineers who concentrate on industrial applications are familiar with the "do's and don'ts" of desiccant systems. In contrast, those who concentrate on commercial HVAC systems are less familiar with the practical considerations of desiccant system design. Many are interested in learning more about desiccant applications and system design.

In an effort to respond to requests from the ASHRAE membership for more detailed information about desiccants, ASHRAE Technical Committee 3.5 (Sorption) has assembled the series of technical papers presented in this publication.

The papers respond to many of the questions frequently heard by TC 3.5 members concerning the technology. These questions include

• Why is it useful to remove moisture from air with desiccants rather than by using condensing coils?

• What are the indoor air quality and human health implications, both positive and negative, of controlling humidity at levels lower than conventional practice?

• What are useful and practical desiccant systems now as compared to the future? What new concepts are emerging from research and development efforts for the future?

• Which applications really benefit from desiccant-assisted air conditioning? What exactly are the benefits and how are the systems designed?

• What are the operating principles behind desiccant systems? How can their behavior be predicted from these fundamental principles?

• Desiccant systems often treat the latent load separately from the sensible heat load. What implications does this have for load calculations and system design?

In an effort...