Comparison of Energy Performance of Different HVAC Systems for a Typical Office Room and a Typical Classroom

This report is part of the work performed under the project “Natural cooling and Ventilation through Diffuse Ceiling Supply and Thermally Activated Building Constructions”. In this project, a new system solution combining natural ventilation with diffuse ceiling inlet and thermally activated building systems (TABS) is proposed for cooling and ventilation in office buildings. Due to the application of diffuse ceiling inlet, cold outdoor air can be supplied into the room without any risk of draught. This means that natural ventilation is available even in winter and it is beneficial to reduce the energy consumption for buildings with cooling demand in cold seasons. In this way, the building system can operate at a very low energy use all the year round.

The main purpose of this task is to investigate the energy performance of different HVAC systems used in the office room and the classroom, and find the potential of energy saving for the proposed new system solution. In this report, a typical room is selected according to the previous study, but the occupation is different for the purpose of the office and the classroom. Energy performance of these two types of room under different internal heat loads are evaluated and compared, including cases with and without diffuse ceiling panel, with and without heat recovery, using traditional air-based system and TABS system. At last, the comparison results are presented and some important issues are discussed.