| Author: | Leung, Yuen-chong |
| Title: | Developing a condensate-free fan-coil system |
| Degree: | M.Eng. |
| Year: | 2009 |
| Subject: | Hong Kong Polytechnic University -- Dissertations. Office buildings -- China -- Hong Kong -- Energy conservation. Office buildings -- China -- Hong Kong -- Heating and ventilation Air conditioning -- China -- Hong Kong -- Design and construction |
| Department: | Department of Building Services Engineering |
| Pages: | xi, 121 leaves : col. ill. ; 30 cm. |
| Language: | English |
| Abstract: | Recent research studies are advocated to decoupling dehumidification from cooling to improve indoor air quality and reduce energy consumption. The use of dedicated outdoor air ventilation (DV) system combined with dry fan-coil (DC) system is proposed in this study. In the DCDV system, the DV system treats all the latent loads and part of the sensible loads whist the DC system treats the remaining sensible loads. To investigate the energy and feasible use of the DCDV system in hot and humid climate, a simulation programme - Energyplus was used to simulate the energy use and the achievable room conditions for its application in a typical high-rise office building in Hong Kong. A comparison was made between a conventional constant air volume (CAV) air-conditioning system and the DCDV system in terms of energy use and achievable room conditions. The results indicate that energy is saved by applying the DCDV system to a representative high-rise office building in Hong Kong. It is found that the application of the DCDV system leads to reduction in pump energy use by 48.6% while in total energy use by 3.7%. A parametric analysis was conducted to explore the influence of six design parameters on the performance of the DCDV system in achieving the desired room conditions, and keeping the fan-coil dry. It was found that the performance of the DCDV system is most affected by the change in fresh air intake rate, supply air temperature and room set-point temperature. However, regardless of the input parameters, condensation occurs on the fan-coils on all Monday mornings. This is due to the intermittent operation of the air-conditioning system to accumulate excessive space sensible and latent over the weekends. In resolving this problem, three strategies were proposed in this dissertation of which the proposed latent load shifting strategy and the continuous operation of air-conditioning system are found to be more practical in optimizing the performance of the DCDV system. |
| Rights: | All rights reserved |
| Access: | restricted access |
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|---|---|---|---|---|
| b23034713.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 5.31 MB | Adobe PDF | View/Open |
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