制冷与空调专业英语第2版 林慧珠 主编 1-2新.pptVIP

Unit One Lesson 1 Air Lesson 2 The Need of Conditioning Lesson 3 The Cleaning of Air Lesson 4 Thermal Storage Lesson 2 The Need of Air Conditioning New Words Expressions: Text Notes to the Text Exercise Lesson 2 Lesson 2 Text Briefly，air conditioning is necessary for the following reasons. Heat gains from sunlight and electric lighting, in particular, may cause unpleasantly high temperatures in rooms, unless windows are opened .If windows are opened, then even moderate wind speeds cause excessive draughts, becoming worse on the upper floors of tall buildings. 简而言之，空调为下列情况所必需。太阳光，尤其是电灯照明的热量，会使房间内的气温很高，令人不舒服，这时就需要打开窗户；而如果窗户被打开，那么即使是中等程度的风速也能导致通风过度，较高楼层上的房间情况会更糟。 Further, if windows are opened, noise and dirt enter and are objectionable，becoming worse on the lower floors of buildings, particularly in urban districts and industrial areas .In any case, the relief provided by natural airflow through open windows is only effective for a depth of about 6 meters inward from the glazing. 进一步说，如果窗户打开，噪声和灰尘就会进入，令人讨厌，尤其是市区和工业区建筑物的最低层情况会变得更糟糕。通过开窗获得自然气流去缓和这种情况，仅限于从玻璃窗向内6米的范围之内。 It follows that the inner areas of deep buildings will not really benefit at all from opened windows. Coupled with the need for high intensity continuous electric lighting in these core areas, the lack of adequate ventilation means a good deal of discomfort for the occupants. 1 Mechanical ventilation without refrigeration is only a partial solution. 由此得出，事实上开窗对纵深的建筑物内部的区域根本无效。加上这些中心区域要有高强度长时间的照明，缺少足够的通风会使居住者感到非常不适。不带制冷的机械通风仅仅只能解决一部分问题。 It is true that it provides a controlled and uniform means of air distribution, in place of the unsatisfactory results obtained with opened windows (the vagaries of wind, again particularly with tall buildings, produce discontinuous natural ventilation), but tolerable internal temperatures will prevail only during winter months .For much of the spring and autumn, as well as the summer, the internal room temperature will be