David Pearlmutter

Urban Microclimate : Designing the Spaces Between Buildings

Preface Introduction 1. Scales of Climatic Study 2. The Urban Energy Balance 3. The Urban Heat Island 4. Urban Airflow 5. The Energy Balance of a Human Being in an Urban Space 6. Thermal Preferences 7. Application of Climatology in Urban Planning and Design 8. Microclimate Design Strategies in Urban Space 9. Vegetation 10. Linear Space 11. Modelling the Urban Microclimate Case Study 1: Neve Zin Case Study 2: Clarke Quay Glossary

Evaluation of Urban Surface Energy Fluxes Using an Open-Air Scale Model

Abstract The thermal behavior of an urban surface is crucial to understand, but it is difficult to predict using conventional measurement or modeling approaches. In this study, an integrated method is proposed for evaluating urban energy exchanges with an open-air scale model of a building–street canyon surface array. The technique, which potentially combines the flexibility of modeling with the reliability of empirical observation under natural turbulence and radiative loading, is tested in hot, arid summer conditions to gauge its ability for reproducing surface–atmosphere energy fluxes that are representative of diurnal patterns in actual urban settings. After identifying the inertial sublayer, which is created above the scaled roughness array at a point near its downwind edge, roughness parameters utilized in the calculation of turbulent sensible heat flux are determined for two different array configurations of varying frontal area density and compared with existing data from field studies and morphom...

Adaptive architecture: integrating low-energy technologies for climate control in the desert

Abstract The article describes a ‘climatically adaptive’ approach to intelligent building in which a variety of technologies are integrated in the architectural design to provide thermal comfort with a minimal expenditure of energy. This concept is illustrated by the design of the Blaustein International Center for Desert Studies, a multi-use complex completed recently at the Sede-Boker Campus of Ben-Gurion University of the Negev. In response to the local climate of this desert region, a number of strategies were developed by the authors to exploit natural energy for heating and cooling: earth berming of major parts of the building, ‘selective glazing’ for seasonal shading and energy collection, a down-draft ‘cool-tower’ for evaporative cooling and a hybrid mechanism for hot-air supply are several of the unique systems whose performance and feasibility are analyzed within the context of the overall building design.

A novel thermal simulation model and its application on naturally ventilated desert buildings

Abstract A new thermal simulation model, QUICK II, is presented and numerous verification case studies performed on naturally ventilated buildings are discussed. Four new case studies performed on two buildings located in the Negev desert in Israel are discussed in detail. All the measurements pertaining to these new case studies were taken independently by the Desert Architecture Unit of the Jacob Blaustein Institute for Desert Research. These measurements are provided, along with a description of the buildings. The verification results show a good correlation between the measured and simulated parameters. The simulated temperatures were found to be within 1 °C of the measured temperatures for 73% of the time, and within 2 °C for 95% of the time.

An open GIS framework for recording and analysing post-occupancy changes in residential buildings — a climate-related case study

Abstract A GIS-based method is proposed, which simplifies recording and analysis of post-occupancy changes in residential buildings. Each modification is considered as a unique record in a database, and has a string assigned to it in a multi-parametric matrix. Its position in the matrix is determined by functional relationships with other housing modifications, orientation, adjacent inner and outer spaces, building materials and physical size. The method was tested in three residential neighbourhoods in two towns in the Negev desert of Israel, with the intention of (a) highlighting modifications related to the climatic performance of buildings and (b) developing a set of recommendations aimed at improving the design of new residential buildings. In the buildings surveyed, post-occupancy changes were made primarily in ground-level apartments and in outdoor private spaces. Building modifications appear to vary in different functional areas of the dwelling units, suggesting a connection between dweller preferences and climatic response.

Human-biometeorological conditions and thermal perception in a Mediterranean coastal park.

This study looks at the interrelation of human-biometeorological conditions, physiological thermal stress and subjective thermal perception in the design and use of a new waterfront park in Tel-Aviv, Israel. Our initial assumption was that the parks design would embody a comprehensive response to the areas ever-increasing heat stress and water shortage. However, almost half of it is covered by grass lawns, irrigated with fresh water, while the remaining area is mainly covered with concrete paving, with minimal shading and sparse trees. We hypothesized that stressful thermal conditions would prevail in the park in the summer season and would be expressed in a high discomfort perception of its users. Thermo-physiological stress conditions in a typical summer month were compared with the subjective comfort perceptions of pedestrians surveyed in the park. It was found that even during mid-day hours, the level of thermal stress tends to be relatively mild, owing largely to the strong sea breeze and despite the high intensity of solar radiation. Moreover, it appears that the largely favorable perception of comfort among individuals may also result from socio-cultural aspects related to their satisfaction with the parks aesthetic attractiveness and in fact its very existence. Adaptive planning is proposed for such vulnerable regions, which are expected to experience further aggravation in thermal comfort due to global as well as localized warming trends.

An assessment of regional constraints, needs and trends

This article briefly reviews regional constraints and trends, among them environmental climatic and social ones, existing and developing in the regions of the Middle East and North Africa (MENA) and which should affect planning, design and construction policies and practices. It reviews the current state of legislation regarding energy and other green building issues, as well as the various voluntary tools which are being promoted in the region. This paper concludes that the pace of building practices adaptations is far from meeting the pace of needs and constraints. The repercussions on the livability of buildings and settlements, and the survivability and resilience potential of communities in the arid regions of MENA, may well be at risk. Thus, for many countries in the region, green building (and the standards that encourage this) is not a luxury of developed countries, which they might adopt in the future once more pressing constraints are eased, but, rather, a critical development goal to lessen these constraints and allow a viable path into such a future.

Roof Geometry as a Determinant of Thermal Behaviour: A Comparative Study of Vaulted and Flat Surfaces in a Hot-Arid Zone

The paper presents a quantitative comparison of the relative solar exposure and thermal behaviour patterns of semi-cylindrical and flat roof surfaces under typical conditions in a hot-arid climatic zone, based en results obtained from mathematical and physical models. A review of sources on the subject is followed by a description of the experimental methods used to model solar and thermal effects on the various roof surfaces, and by an analysis of the results obtained from these models.

Monitoring the Thermal Performance of an Insulated Earth-sheltered Structure: A Hot-arid Zone Case Study

An earth-sheltered structure built in the arid Negev Highlands of southern Israel was monitored during several seasonal periods in order to analyse its thermal behaviour and to determine the appropriateness of this type of building for the Negev and climatically similar regions. Temperatures were measured at various points within the building, which consists of two connected concrete shell domes totalling 58m2 in floor area. A comparison of thermal conditions was made between various operating patterns, which included the introduction of shading and night ventilation for cooling and direct solar gain for heating. Mechanical heating was used in winter for the evaluation of energy input required to maintain comfort conditions. The paper analyses various thermal effects of the earth cover and of the particular envelope design, based on temperature measurements taken both in the interior space and within the soil, and evaluates the particular design approach taken in terms of its appropriateness for the given...

Green building standards as socio-technical actors in municipal environmental policy

ABSTRACT Methods for the environmental assessment and certification of ‘green’ buildings are increasingly being adopted by local governments and other entities as a means of meeting environmental, and often energy-related, goals. Literature on building environmental assessment has examined how these tools are interpreted by stakeholders in design and construction, but less attention has been paid to their interpretation and usage as objects of policy – despite this being a channel through which they have a potentially huge impact. Based on a case study of the emergence of green building in Israel, and drawing on socio-technical literatures, this paper explores the meanings attributed to building environmental assessment in the policy context. It finds that these meanings include a platform for divergent environmental goals and a proxy measure for greenhouse gas abatement. The analysis suggests that for policy-makers, the significance of green building lies not in its constituting a set of environmental benchmarks but as a standard that gains currency as a black-boxed policy object. An open discussion is needed on the various logics driving the use of green building tools in public policy, and what they hope to achieve.