When I came to Israel (then Palestine) 50 years ago and inquired about the influence of the summer climate on construction and town-planning I received only o n e answer: the cool breeze comes from the west! I began intensive studies and succeeded in assembling a team of specialists: for physical problems Prof. Goldberg (formerly from Zeiss~lena), the Profs. Strauss and Gruschka for questions of hygiene, and the Director of the Meteorological Service of the then Mandatory Government, Mr. Feige, for meteorological problems. Theoretical considerations and calculations led to results which could be confirmed by subsequent measurements. An analysis in the form of a Table will demonstrate the variety of the problems (see Table 1). A large-scale measurement programme of the Government Meteorological Service (then of the British Mandate), carried out in 1946, confirmed that part of my theoretical considerations and calculations which was being investigated. This programme dealt with a comparison of two equal flats in the coastal plain, one apa r tmen t facing north and south, and the other one east and I quote the results word for word: combined amounts of insolation received by the walls facing north and south are less than the combined amounts reaching walls facing east and west. And further: the daylight hour winds have an important northerly component, while the night-time land breezes have a prominent southerly component . Therefore, we have known for nearly 40 years that the main walls should face north and south -a knowledge of basic importance for construction and town planning in Israel. Not much later the research institute at the Haifa Technion was established, so that under the direction of Prof. Givoni our knowledge could be considerably expanded. I would now like to give a condensed summary of our knowledge and of the most important measures which ought to be taken in our daily practice. To begin with: we know under what conditions a person feels continously comfortable! Although we should not underestimate the problems of winter, we wish to restrict ourselves here to summer problems. In summer the most important task is to take care of sufficient heat removal from the human body. Since the body inside a room is only in slight motion or at rest and therefore tends to disperse heat mainly by radiation, it is our first and foremost task to see to an optimal cooling of the radiating surfaces, i.e., the inner surfaces of walls, ceilings and floors. If we cannot obtain a sufficient radiative dispersion of the body heat we must endeavor to increase heat dispersal by conduction to the air. This is attained by setting the surrounding air in motion. The moving airstream frees the skin of heated air, surrounding the body, which may reach on hot days 33 -34 °C. It directs cooler air toward the skin, resulting in a refreshed feeling, provided the air temperature does not exceed 31 °C. So as not to cause damage to health an evenly agitated airstream should fan the body from all sides. The largest refreshing effect will be obtained with relatively light air motion (velocity of about 0 .51.5 m/s), when the danger to health is also minimal. So the basic hygienic facts are known to us, and in consequence the task of the town or village planner and the architect as builder of single buildings becomes quite clear: he must arrange for the cooling of the interior walls, ceilings and floors, and in many parts of the country, for an adequate motion of the air within the rooms. The means of achieving this are again, in principle, well-known, although we still require further detailed knowledge about
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