The characteristics of a hybrid air-conditioning system, utilising natural and mechanical 'task' ventilation, are investigated in an office setting. The characteristics of the indoor environment are examined by means of CFD (Computational Fluid Dynamics) simulations under various conditions of incoming outdoor air. The control of the task air conditioning system (VAV system) is included in the calculation through changing the supply air volume to keep the task zones temperature at a target temperature.
This paper examines the impact on domestic background air infiltration of replacing ‘old windows’ with modern double-glazed and draught sealed windows, both with and without controllable ventilation (e.g. trickle ventilators). Methods of estimating the change in infiltration rate produced by such a window replacement are reviewed. A simple model has been developed which, using laboratory measurements of window air permeability, predicts the reduction in infiltration that can be expected when a given number of windows are replaced in a dwelling.
The ventilated ceiling is a flexible solution for kitchen ventilation where heat loads are relatively low and aesthetics is a concern. By using a capture jet in the ventilated ceiling, it is possible to improve the total effectiveness of the ventilation system. This means better indoor air quality and thermal comfort. In addition, the energy consumption of a capture jet ceiling is lower than that of a traditional ceiling concept.