Baruch Givoni

Comfort, climate analysis and building design guidelines

Abstract The paper discusses issues of thermal comfort standards, including the ASHRAE comfort zone, techniques of graphical climate data analysis, as well as the uses of building bioclimatic charts in the formulation of building design guidelines, especially for hot climates. The problematics of applying the Olgyay bioclimatic charts and the ASHRAE comfort standards for unconditioned buildings, especially in developing hot countries, are discussed. Revised building bioclimatic charts are described for the first time in this paper. The boundaries of applicability of various building design strategies and passive cooling systems in different climates are discussed. These strategies are based on the expected indoor temperatures achievable with the different strategies and include daytime ‘comfort” ventilation, the utilization of the structural mass for thermal storage in conjunction with nocturnal ventilation, and direct and indirect evaporative cooling.

Outdoor comfort research issues

The paper discusses methodological issues and carrying out problems in outdoor comfort research. It also deals with the relative effects of air temperature, solar radiation and wind speed, as well as with the relationship between thermal sensation and overall comfort sensation, as was found in the outdoor comfort research in Japan. The paper also summarizes several studies going on presently at Tel Aviv University in Israel and presents some of the actual experimental results from these studies.

Impact of planted areas on urban environmental quality: A review

The paper discusses the impact of urban planted areas: public parks and private planting around individual buildings, on various aspects of the quality of the urban environment. Specific issues discussed are: • functions and impacts of urban planted areas; • effect of plants on the climatic characteristics of an area; • climatic impacts of private planted areas around buildings; • experimental studies on the thermal effect of plants; • public parks and the urban climate; • range of the effect of urban parks; • impact of green spaces on air pollution; • planted areas as noise; • social functions of urban parks; • parks as social interaction areas between neighborhoods; and • summary: Climatic guidelines for parks design: ◦ Parks in hot, dry regions; ◦ Parks in hot, humid regions; and ◦ Parks in cold regions. Comment: This paper is based on a book by the author, published by the World Meteorological Organization (Givoni, 1989, Urban Design for Different Climates, WMO).

Effectiveness of mass and night ventilation in lowering the indoor daytime temperatures. Part I: 1993 experimental periods

Abstract Buildings with different mass levels were monitored in the summer of 1993 in Pala, South California, under different ventilation and shading conditions. The effect of mass in lowering the daytime (maximum) indoor temperatures, in closed and in night ventilated buildings, was thus evaluated. Night ventilation had only a very small effect on the indoor maxima of the low-mass building. However, it was very effective in lowering the indoor maximum temperatures for the high mass building below the outdoor maxima, especially during the ‘heat wave’ periods. On an extremely hot day, with outdoor maximum of 38 °C (100 °F), the indoor maximum temperature of the high-mass building was only 24.5 °C (76 °F), namely within the comfort zone for the humidity level of California. Comment: In 1994 the monitoring has been continued, first with the original dark color of the envelope and then with the buildings painted white, as well as under natural, all-day ventilation with open windows. The results of the 1994 experiments will be reported in Part II.

Performance and applicability of passive and low-energy cooling systems

Abstract The paper summarizes the state of the art of passive and low-energy cooling systems for buildings: comfort ventilation, nocturnal convective cooling, radiant cooling, direct and indirect evaporative cooling, and utilization of the soil as a cooling source for buildings. The factors which affect the performance of each cooling system, its design implications and its applicability for different building types and climatic conditions are discussed. Results are given of experimental studies, mainly by the author, evaluating the performance of various cooling systems.

Earth temperatures and underground buildings

Abstract Previous experimental studies have dealt with the earths surface and subsurface temperature profiles. The results from these studies have been summarized and analysed jointly, making it possible to derive some generalizations. It appears that the temperature range decrement factors for the different studies fit within a narrow range, and that they suggest a classification by climatic type. The values for the time lag in the annual temperature wave were also found to fall within a narrow range. Simplified equations are presented for determining soil temperatures and time lags as a function of depth. Different approaches for estimating the surface temperature are presented and discussed.

Characteristics, design implications, and applicability of passive solar heating systems for buildings

The paper reviews the performance characteristics of various passive solar heating systems for buildings, the main design factors affecting their performance, the relative advantages and main problems associated with them, and their applicability to different building types and climatic regions. Emphasis is placed on the architectural design issues associated with the different passive solar heating systems and to the problems that may be encountered when passive solar heating is applied in regions with hot summers.

Performance of the “shower” cooling tower in different climates

The paper summarizes experimental data from testing a new type of a passive cooling system developed by the author, the “Shower” tower, and compares its performance under three different climatic conditions: Los Angeles in California, USA, Riyadh (Saudi Arabia) and Yokohama (Japan).

Experimental performance of the shower cooling tower in Japan

We tested this system with objectives to plan and apply this system in Japan, and examined its cooling effectiveness and ir flow generation

Urban design for hot humid regions

The paper discusses the design objectives and the urban design elements which affect and can modify the urban micro-climate in hot humid regions. The design elements discussed are: Location of towns in a region; Density of the built-up area; Orientation and width of streets; Building design details affecting the comfort of people outdoors, and the Design details of public and private “green” areas. Urban design details are suggested for hot humid and for hot dry regions. The paper is based on a recent book of the author (Givoni 1994).