4804 - Desiccant Dehumidification with Hydronic Radiant Cooling System for Air-Conditioning Applications in Humid Tropical Climates

This paper discusses the feasibility of a hybrid desiccant dehumidification system combined with chilled ceiling for airconditioning applications in humid tropical climates. The study presents a design/operation guide of the hybrid system. The study also indicates definite merit of the hybrid system when the ventilation air requirement of the conventional system is above a certain threshold. This is particularly so in many practical applications, where a high ventilation air requirement is desirable or mandated, such as operating theaters and certain hospital wards. A trial run on the facility indicates the viability of the scheme, particularly the absence of condensation/sweating of chilled panels. In the same context the facility developed to conduct experiments is described. For a space loading of 0.1 kW/m² (31.71 Btu/h·ft²), any ventilation rate above 2% for a conventional system offers opportunity for downsizing chiller capacity of the hybrid system. Based on an indicative energy analysis, the proposed hybrid system becomes more energy efficient than a conventional system when the required ventilation rate is 30% and above.