The evaluation of energy performance for a teaching and research complex located in South Florida was carried out by auditing the energy bills, on-site data monitoring, and numerical simulation by computer. To facilitate the process of on-site data monitoring, a remotely controlled, wireless thermal monitoring system was deployed in the building. The system can automatically collect the temperature, relative humidity ratio, illumination intensity, and building electricity usage data for analysis. The contribution and savings potential of each energy consumption component is analyzed for the whole building. From the audit result it is obvious that laboratory equipment is the dominant electricity consumption factor. The fluctuation pattern of electricity usage due to artificial lighting demonstrates the effectiveness of occupancy sensors for energy saving during evenings, weekends and holidays. The trend of HVAC chilled water consumption rate follows closely with the indoor and outdoor temperature difference. Since the HVAC coil load represents the building's total cooling requirement, the ratio between chilled water rate and temperature difference reflects the building's comprehensive thermal resistance. This coefficient can be used as a new building energy index for future energy audits of similar buildings. Finally, computer software simulates several proposed energy saving scenarios, e.g. reducing the HVAC fresh air percentage, adding energy wheel to recycle the wasted cooling, etc. The result shows that installing energy wheel can save more cooling load than other methods, however such benefit is compromised by its extra motor electricity usage.
Developing an Integrated Method for Optimal Design of Chilled Water Plants in HVAC Systems
