| Title |
Effects of Temperature, humidity and flow rates of Incoming Outdoor Air on Indoor Environment Air Conditioned by Hybrid System Utilizing Natural Ventilation |
| Keywords |
Natural Ventilation ; Computational Fluid Dynamics ; Task/Ambient Air Conditioning ; VAV |
| Abstract |
The performance of a hybrid air-conditioning system which utilizes wind-induced cross ventilation is investigated in the office setting. The characteristics of flow, temperature fields, humidity fields and age of air are examined using CFD simulation under various conditions of in-flowing outdoor air, i.e.,change in air temperature, humidity and variable air exchange rate. The room air controlling system (VAV system) which is used to keep the task zone at a target temperature in this simulation, is reproduced through changing the supply airflow rate of the air-conditioning system. With that, we can estimate how much cooling heat is required by the air-conditioning system to keep the task zone at the target temperature, and can analyze the details of the flow and the temperature fields in their respective conditions. When the outdoor air flows into the room sinks to close to the ground, it does not mix with the air in the room, and thus can cools the task zone well. The cooling load of the mechanical AC system is shown to increase with both the increases of the outdoor air temperature, and with the decreases of the in-flowing outdoor air volume. |