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Current potential research project

Residential application of liquid desiccant systems in South East Asian tropical climates

  1. Supervisors: Prof. Wasim Saman
  2. Area: Mechanical Engineering, Sustainable Energy
  3. Abstract: Thermal comfort provision in residential and commercial buildings in tropical South East Asia is a serious challenge often not able to be met by conventional vapour compression refrigerative systems. Little variation of outdoor air temperature and humidity all year round are characteristics of this region. The thermal performance of conventional vapour compression air conditioners installed in this region has been often the subject of buildings occupants’ complaints: it is either too cold or too stuffy. This is due to the inability of these systems to satisfy simultaneously the sensible and latent loads independently when the off-design conditions occur (Rudd et al., 2005, Luxton & Shaw, 1991). These systems therefore are only able to perform reasonably well during the periods in which design conditions prevail which only occur at the very short period annually. Mismatch between cooling characteristics of this hot and humid region and the conventional refrigerative system capability has often resulted in wasted cooling energy whilst the occupants’ comfort is often compromised. Liquid desiccant air conditioning is a type of thermally driven open cooling cycles based on a combination of evaporative cooling and dehumidification by a desiccant (Henning, 2007). A number of advantages of desiccant systems over the closed-cycle systems are (Saman et al., 2004): they operate at ambient pressures, heat and mass transfer occurs in direct contact, and both air cooling and dehumidification can be provided independently according to the prevailing load. A recent numerical study by Krause et al. (2006) has shown that such a system is technically viable for subtropical regions of Australia such as Brisbane. However, to the best of authors’ knowledge, no study has been carried out to investigate the viability of such a system in a hot and humid climatic region such as South East Asia. One of the characteristics of desiccant systems is their efficient handling of latent load but less efficient handling of the sensible load (Gommed & Grossman, 2004). On the other hand, conventional vapour compression systems work well in handling the sensible cooling load but often fail to meet the room’s latent load (Luxton & Shaw, 1991). The proposed research will carry out a comprehensive study on the potential application of liquid desiccant air conditioning system in four cities in South East Asia: Bangkok (Thailand), Jakarta (Indonesia), Kuala Lumpur (Malaysia) and Singapore. The characteristics of cooling loads in hot, humid climate will be numerically investigated. Thermal performances of liquid desiccant absorber and regenerator under these simulated conditions will be investigated experimentally. The research will also evaluate how a liquid desiccant sub-system and a vapour compression sub-system can be coupled to deliver the optimum cooling performance for this climatic condition.
  4. Related references: No reference provided

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