Screening Tool for Desiccant Dehumidification Applications

Abstract

A state-of-the-art software tool that calculates the benefits of desiccant-based air-treatment equipment is described. The software, a Desiccant Systems Application Screening Tool, is written in the WindowsTM environment to promote user-friendliness. Its graphical interface emphasizes the simplicity of using default values or, if desired, provides the user with the option of customizing the input. The program runs annual loads/energy calculations with the electric equipment selected by the user (from a library of typical systems) and compares performance of a conventional system to an alternative electric system supplemented with a commercially available desiccant dehumidifier providing the required air-conditioning performance. The screening tool uses DOE 2.1E as the computational engine, which runs in the background and is transparent to the user. In addition, the latest TMY2 meteorological data recently released from the Department of Energy National Renewable Energy Laboratory are used by the program. Output of the program provides the user with a clear comparison between the performance of a desiccant/electric system and conventional system installed in an identical application. Specifically, the comfort issues are emphasized by comparing the number of occupied hours when the relative humidity in the building exceeds 60% RH (or above specific RH set point, if controlled). The economics are compared based on the annual/monthly energy consumption and operating cost. A case study is presented.