Design and Experimentation of a Manufacturable Solid Desiccant Wheel Assisted Separate Sensible and Latent Cooling Packaged Terminal Air Conditioning System

Abstract

Packaged terminal air conditioning (PTAC) systems are typically utilized for space heating and cooling in hotels and apartment buildings. However, in an effort to reach comfortable relative humidity in the conditioned space, they cool the air to its dew point and some reheating may be required to reach room set point temperature. In this study a commercial prototype of a solid desiccant wheel assisted separate sensible and latent cooling (SSLC) packaged terminal air conditioning (PTAC) system was designed . This iteration of the SSLC prototype was modeled based on PTAC type air conditioning units and was designed to achieve a 30% increase in system efficiency over current commercially available PTAC units. Heat exchangers used as evaporator and condenser were modeled in Coildesigner and VapCyc was used for system level modeling. Also a test facility was constructed in order to evaluate the performance of the proposed SSLC unit. Shakedown testing was conducted under various operating conditions in order to compare the SSLC system to a standard PTAC unit without desiccant wheel. With the necessary adjustments to the experimental prototype, the system could increase the overall capacity through latent cooling with negligible additional power consumption.