Urban Office Buildings Research Articles

Strategies for Natural Ventilation of Urban Office Buildings

The world urban population is expanding, resulting in taller buildings and increased building density. This paper describes a design approachfor the natural ventilation of high-rise buildings based on a double faÈade structure in which an external cladding is used in conjunction with a central air-well with wind catcher ("hood").Boundary layer wind tunnel testing was used to determine wind pressure distributions for different wind directions on model buildings with different width to depth aspect ratios. Pressure coefficients, determined for the surface of the building behind the cladding, showed that negative (suction) pressures were developed. These negative pressures, in conjunction with the positive pressures produced by the air-well with a wind catcher (pointing into the wind) provide natural ventilation potential. The external cladding/hooded air-well building was compared with a conventional cross ventilated building in terms of thermal comfort for a range of climate conditions. The results indicated that the ventilation potential of the conventional building was dependent on the building orientation with respect to the prevailing wind, but the external cladding/hooded air-well system was found to be independent of wind direction.

Airborne Concentrations of Volatile Organic Compounds, Formaldehyde and Ammonia in Finnish Office Buildings with Suspected Indoor Air Problems

A database of indoor air concentrations of volatile organic compounds (VOCs) (n = 528), formaldehyde (n = 76), and ammonia (n = 47) in office environments was analyzed to suggest interpretation guidelines for chemical measurements in office buildings with suspected indoor air problems. Indoor air samples were collected for VOCs from 176 office buildings, 23 offices for formaldehyde, and 14 office buildings for ammonia in 2001–2006. Although the buildings had reported indoor air complaints, a walk-through inspection by indoor air specialists showed no exceptional sources of indoor air pollutants. The measurements of chemical pollutants did not indicate any clear reason for the complaints. The geometric mean concentration of total volatile organic compounds (TVOC) was 88 μg m−3 in office rooms and 75 μg m−3 in the open plan offices. The mechanical supply and exhaust ventilation significantly (p < 0.004) decreased the indoor air concentration of TVOC. The highest mean concentration and frequency distributions were determined for the individual VOCs. The most common VOCs found in ⩾ 84% of the indoor samples include toluene, xylene (p,m), 1-butanol, nonanal, and benzene. According to concentrations, the most abundant VOCs were 2-(2-ethoxyethoxy)ethanol, acetic acid, 1,2-propanediol, and toluene. The geometric mean concentration of formaldehyde and ammonia in the office buildings was 11 μg m−3 (3–44 μg m−3 and 14 μg m−3 (1–49 μg m−3, respectively. On the basis of statistical analyses, the guideline value indicating a usual concentration of the pollutant in office buildings is 70 μg m−3 for TVOC, 7 μg m−3 for most individual VOCs, 10 μg m−3 for formaldehyde, and 12 μg m−3 for ammonia… The guidance value suggested for TVOC is 250 μg m−3, for formaldehyde 15 μg m−3, and for ammonia 25 μg m−3. If the guidance value is exceeded, this may indicate the existence of an exceptional source and the need for additional environmental investigations. The levels should not be used for the evaluation of health risks. The guideline values are applicable in a subarctic climate for modern, urban office buildings.

１９９０年代の東京２３区における都市密度変化と土地利用転換―事務所建築物と集合住宅を対象として―

The purpose of this study is to clarify, from a macro-scale viewpoint, the characteristics of urban density growth and patterns of land use change in Tokyo 23 wards from 1991 to 2001, which corresponds to a period of recession. The changes in urban density and former land use where office buildings and multiple dwelling units (MDUs) were located are measured quantitatively. The number of office buildings increased while the number of MDUs hardly changed. However, due to mass construction of high-rise buildings, both the density surfaces of urban office buildings and MDUs developed significantly during the decade. The highest density of office buildings was observed in three wards of central Tokyo. Because numerous office buildings were constructed in those areas, the accumulation of office buildings shows a growing tendency. Construction of many MDUs in commercial and business areas became a factor enhancing population inflows to central Tokyo. The characteristics of the former land use of MDUs differ by area. Some of the highest density spots for the total floor space of MDUs in 2001 are found in the eastern part of Tokyo because high-rise MDUs accumulated in empty lots where factories or warehouses had been located. The former land use was closely related to areal differences in increasing urban density caused by the City Planning Law or the Building Standard Law.

A simulation of cellular system growth and its effect on urban in-building parasitic frequency reuse

Indoor parasitic cellular systems reuse the same frequencies as outdoor cellular (macrocellular) systems to provide wireless communications inside a building or campus. This paper provides a simulation strategy to determine future channel availability that is possible between in-building and outdoor cellular systems that share the same radio spectrum. Capacity that is currently available inside an urban office building is first derived from field-strength measurements of all the channels in the macrocellular system made inside the building. We then create a simulation that determines the effect of a growing outdoor cellular system on in-building frequency reuse. Future in-building frequency reuse is predicted over a 6-yr timeline in 3-mo intervals and includes the effect of height above ground inside the building. Results show that indoor reuse is practical as long as interference levels of about -85 dBm can be tolerated from the outdoor macrocellular system.

Capital Markets, the Development Industry, and Urban Office Market Dynamics: Rethinking Building Cycles

In this paper it is argued that more attention should be paid to the role of supply-side factors in accounting for the spatiotemporal evolution of urban office building cycles, particularly during the recent boom of the 1980s. Urban office building dynamics are critically related to changes in the structure and operation of finance capital, the development industry, and state intervention; changes which in turn are related to shorter term macroeconomic fluctuations and longer waves of economic and political restructuring at different geographic scales. A comparative analysis of the timing, periodicity, and magnitude of booms and slumps in downtown office construction activity between 1963 and 1986 in major metropolitan areas of the United States reveals a convergence in the timing of booms and slumps in downtown office construction between individual cities and on the national trend in the late 1970s and early 1980s, and a persistence of important differences in the relative volume of downtown office construction between cities. The convergence in timing can be traced to an increased degree of national and international integration of capital markets and the development industry, and the increased flow of capital into commercial real estate. Analysis of interurban differences in the volume of building activity suggest ways in which powerful international and national trends are mediated by locality-specific local economic and political structures and conditions.

Chicago architecture and design

Chicago is world famous for an architectural tradition that has influenced building around the globe. It is the birthplace of the skyscraper and the cradle of modern architecture; it gave rise to the urban office building as we know it, and to the flowing, open floor plans of today's homes. This book chronicles Chicago's architectural tradition from the nineteenth through the early twenty-first century, examining its evolution in the context of broader historical, social, technological, and artistic currents. It explores Chicago architects' quest for a quintessentially American style, and the century of innovation that pushed buildings ever higher, opened them to space and light, and increasingly dissolved the boundaries between indoors and out. It looks at world-renowned structures from the inside out, giving special attention to the interiors that were and remain so important to Chicago's architects. It traces the course of modern architecture from the structural simplicity of Chicago School commercial building, to the low-slung Prairie School house, the streamlined Art Deco skyscraper, and the minimalist Miesian tower of glass and steel, all the way through to the strikingly original, diverse designs of the present day's so-called second modern movement. This eminently readable text vividly discusses both the life and work of such towering figures as Daniel Burnham, John Wellborn Root, Louis H. Sullivan, Frank Lloyd Wright, and Mies van der Rohe - as well as that of the many lesser-known architects who have made outstanding contributions.

Field Studies of Contact Materials: Contact Resistance Behavior of Some Base and Noble Metals

The contact resistance of various metals was determined after exposure of from three months to four years in telephone central offices and in nonair-conditioned locations. The logarithm of median contact resistance was stable for some materials, but with most it increased on aging according to linear, parabolic, or logarithmic time relationships. The kinetics of contact resistance change depended on the intrinsic chemical reactivity of the material, the air pollutants which were present in the exposure site, and especially on the relative humidity. Contact resistance-force behaviors were affected also by the topographic and hardness characteristics of the metals. The overall ranking in central offices on the basis of stability of contact resistance from best to worst was 1) gold; 2)high gold-silver alloys, palladium, high palladium-silver alloys, 60Sn40Pb, and tin; 3) copper, high copper alloys, and nickel; and 4) silver. Where relative humidity was only slightly less well-contro11ed, as in a nonair-conditioned room in an urban central office building, except for gold the contact resistances of all materials were from one and two orders of magnitude greater after 40 months of exposure, and often displayed different kinetic behaviors. Palladium was exposed in a total of 18 sites and its contact resistance was found to be highly variable, even exceeding 1000 \Omega in less than 1 year when relative humidity was high and reactive chlorine-containing air pollutants were present. Pore corrosion of gold electrodeposits and creep of tarnish films from adjacent base metals did not occur in central offices except when the substrate was silver and the level of sulfiding pollutants was high.