Application of desiccant systems for improving the performance of an evaporative cooling-assisted 100% outdoor air system in hot and humid climates

Abstract

The purpose of this study was to enhance the energy-saving potential of an indirect and direct evaporative cooling-assisted 100% outdoor air system (IDECOAS) by integrating it with either a solid or liquid desiccant system. The desiccant system can be installed either at the scavenger air side of the indirect evaporative cooler (IEC) to enhance its effectiveness or at the primary air side of the IEC to reduce the latent load of outdoor air. The operating energy consumption affected by the location and type of the desiccant unit integrated with IDECOAS was simulated under three different hot and humid climates using TRNSYS 17 integrated with commercial equation solver programme. And then, the most energy-conservative configuration was selected for each climate zone as the proposed system. The simulation results showed that configurations with the desiccant dehumidification unit located upstream of the IDECOAS consume 76–85% less cooling coil energy than those with the desiccant unit located downstream of the IDECOAS. It was also found that the liquid desiccant system saves 21–50% more primary energy than the solid one, when it is integrated with IDECOAS.

Keywords:

• liquid desiccant system
• solid desiccant system
• evaporative cooling system
• 100% outdoor air system
• IDECOAS

Funding

This work was supported by the research fund of Hanyang University [grant number HY-2012-N] and Korea Evaluation Institute of Industrial Technology grant funded by the Korean government [grant number 10045236].