| Author: | Hung, Cheung-kwong |
| Title: | Energy simulation for buildings with split type air conditioning systems |
| Degree: | M.Sc. |
| Year: | 1999 |
| Subject: | Air conditioning -- Computer simulation Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Building Services Engineering |
| Pages: | xi, 107 leaves : ill. ; 31 cm |
| Language: | English |
| Abstract: | Recent technological improvements in the capacity, performance, efficiency and flexibility of split type air conditioning systems has given rise to the increasing use of such systems in Hong Kong. One of the key considerations for choosing between split systems and a central air conditioning system is the efficient use of energy. In this research study, guidelines have been established on selection between the use of split type and central systems. The simulation softwares, HTB2 and BECON, were used for simulating heat transfer in buildings and predicting electricity consumption for air conditioning. A computer simulation model for performance simulation of split type air conditioning systems have been developed. The generalised model equations were established by multiple regression techniques based on a range of performance data obtained from different manufacturers. The model predictions were verified by comparisons with manufacturers' data and site measurements, and were found reasonably accurate. A selected building equipped with split type systems were redesigned into a central air conditioning systems. Simulation studies with HTB2 and BECON were conducted to predict the energy consumption. It is noted that the energy consumption of the central system is 5.6% higher than the split system (without ventilation load) and the energy consumption of the split system (with ventilation load) is 36% higher than the central system. The Life Cycle Cost (Cost Per Year) of the split system (without ventilation load) is 56.26% higher than the central system and the Life Cycle Cost (Cost Per Year) of the split system (with ventilation load) is 96.37% higher than the central system. Additionally, simulation studies were also conducted to predict the energy consumption of large, medium, small and very small size office buildings. It was noted that the use of split system for very small office are in general with lower energy consumption than that of central system. From the simulation studies, the following observations are noted: 1. Without taking into account the ventilation load, the energy consumption for split system is in general lower than central system for large, medium, small and very small office buildings. 2. Taking into account the ventilation load, the energy consumption for split system is around 40% higher than the central system for medium and small office buildings and improvement is noted when the size of the building is decreased. The energy consumption of the central system is higher than the split system for very small office buildings. 3. The construction time for split system is much better than central system for large, medium, small and very small office buildings. 4. The Life Cycle Cost (Cost Per Year) of split system is worse than central system for large, medium, small and very small office buildings, but, improvement is noted when the size of the building is decreased. It can be concluded from the simulation studies that the split system can be considered for medium and small office buildings and is suitable for very small office buildings. Based on the relevant literature and the results of the simulation studies, guidelines and procedures have been established on selection of split type and central systems. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b14852524.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.64 MB | Adobe PDF | View/Open |
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