Moisture Barriers

Moisture control is targeted at two very different forms of water intrusion. First, there is the control of moisture that enters in the form of water vapor. Second, there is the need to control the entry of liquid water from driving rain or other sources. Controlling the entry of water and managing any that has entered is the primary way in which to diminish the failure risk of elements within the exterior envelope assembly and to add durability and lifetime to building products. As with air...

Stakeholders

Effective policies must be designed according to an assessment of the stakeholder needs. Housing market stakeholders include occupants, potential occupants, developers, design teams, energy suppliers, and policy makers. A critical analysis of each stakeholder's set of needs and frames yields valuable information for policy designers. Occupants and potential occupants comprise the demand side of the market. In China, two primary ideological barriers hinder the transformation to a market system....

Mmtw

Figure 9 Wind velocity distribution at the height of 1.5 m above the ground around the buildings for scheme I with a north wind (blue - low velocity, green - moderate velocity, and yellow red -high velocity) Figure 9 Wind velocity distribution at the height of 1.5 m above the ground around the buildings for scheme I with a north wind (blue - low velocity, green - moderate velocity, and yellow red -high velocity) Velocity 1. OSOEtOl 9.605E+00 3.40SE+0Q Figure 10 Wind velocity distribution at the...

Window Orientation Shades and Overhangs

Solar gain through windows should be minimized by orienting buildings on an east-west axis as shown in Figure 19, with as much surface area as possible facing north and south. Designers should use overhangs and shades, and select glazing with low solar heat gain coefficients. Examples of shading devices are shown in Figure 21. Figure 19 Study 3 - site diagram of the Shenzhen Wonderland housing development under investigation (north is to the left) Figure 19 Study 3 - site diagram of the...

Climatic Strategies

General climatic strategies for building in the Beijing area took into account several local environmental factors. Winter heat loss, mainly caused by infiltration, is a persistent problem in other, comparable residential developments in the area. Reduction of heat loss due to infiltration can be primarily addressed on the level of craft skills and construction techniques employed by the local builders. The MIT design team also responded to this problem by reducing the winter wind speed within...

Case Study Two Beijing Star Garden

MIT and Tsinghua were asked by the Design Department of Beijing Vanke Co. Ltd. to develop the site plan and architectural design for a residential development in the area of the former Asian Games site in Beijing (Figure 1). Throughout the process, architects and engineers worked together to design a site plan and building designs that would promote comfortable outdoor and indoor environments. A number of designs and studies were carried out for this project. The first task was to perform an...

Thermal Comfort

Understanding what range of temperatures is considered by building occupants to be comfortable is an important first step in predicting building-energy consumption. This will help identify how such opportunities as using natural ventilation in lieu of vapor-compression cooling affect energy savings and the comfort of the occupants. The international thermal-comfort standard identifies 26 C as the upper bound of the thermal-comfort region under humid conditions (ASHRAE 2001, ISO 1994). This...

Case Study One Beijing Prototype Housing

The Beijing Prototype Housing Projects, including the 12 x 12 house and the 12 x 24 prototypes, were designed in 1998 in collaboration with Tsinghua University for the Beijing Vanke Co. Ltd. The goal was to design a modular prototype for sustainable urban housing that could be applicable to various medium-density sites. These prototypical designs were the first projects explored by the Sustainable Urban Housing in China Group. The demonstration buildingforthe 12x 12 residence was located in...

Shenzhen Wonderland Phase Iv

Shenzhen, located In southern China, is in a region with a warmer climate than Beijing or Shanghai. Vanke Architecture Technology Research Center in Shenzhen invited MIT to work on the site plan and architectural design for energy-efficient housing for phase IV of the Shenzhen Wonderland development (Figure 1). When this project was initiated in 1999, the first two phases of housing were already completed, while phase III and IV were in design development. The program for phase IV included 259...

Case Studies

The goal of the Sustainable Urban Housing in China Project was to develop research on sustainable building principles as applied to housing projects within varying urban regions in China. The lessons learned are the result of a direct relationship between research and practice and are grounded in the diverse range of sociological, political, and economic factors of professional practice. Through the collaboration with local design institutes and developers, the MIT Sustainable Urban Housing in...

Case Study Five Beijing Hui Long Guan

The MIT Building Technology Group and Tsinghua University advised Tian Hong, a development firm, in the conceptual design of a residential development outside of Beijing named Hui Long Guan. MIT undertook the site planning and architectural design for two residential plots within the larger master plan for the Tian Hong Project. These included development parcels C02 and C06, consisting of 89,000 and 148,000 square meters respectively (Figure 1). Tian Hong requested a design strategy with an...

Urban Housing Clusters as a Response to Climate and Community

With respect to typologies, we have an interest in those building forms and shapes that bring together a series of ideas. The resulting form is the one that enables those ideas or parameters to enrich the project. An example of this type of approach is the site-planning principles previously explained in the case of the inner clusters in the Hui Long Guan Project in Beijing. Three housing clusters or blocks make up the center of the project, and each is then further divided into three courtyard...

High Rise Residential Building Complex in Beijing

Highrise Center Green

In the past, a good living environment in China implied ample space between buildings filled with trees and grass. High-rise buildings have been regarded as a symbol of modernity and luxury. A typical building consisting of such residential units is shown in Figure 8. Jiang et al (1999) made a detailed analysis on the design and found that such a design is not sustainable in terms of energy efficiency and Chinese culture. The study showed that the best design would be made up of low-rise...

Wind Data

To design naturally ventilated buildings and or comfortable outdoor environments, the first step is to obtain reliable wind information, such as wind speed and direction. For example, the National Renewable Energy Laboratory derived a set of typical meteorological weather data for 229 stations throughout the United Figure 1 Surface wind roses in January for northeastern U.S. (Source adapted from NOAA 1983) Figure 1 Surface wind roses in January for northeastern U.S. (Source adapted from NOAA...

Natural Ventilation Design

Air Movement Arrow

Figure 2 shows the location of the six-story (20 meters) demonstration building and its surroundings in Beijing City Garden, Beijing. There is a long, mid-rise building, 40 meters high, to the north and low-rise six-story buildings to the east and south. A wide street runs along the west of the demonstration building. Our design in this case focused on natural ventilation. The design of natural ventilation in the demonstration building required data on indoor and outdoor airflow distributions....

Stata Center

Figure 5a shows a model of the Stata Center and its surroundings designed by Frank O. Gehry and Associates. Since this campus building has windy surroundings, the architect was concerned about the outdoor thermal comfort in the plaza (the front part of Figure 5a). At one time, the architect wanted to add a glass roof that would provide a wind shield over the plaza. Since the glazed roof would cost several million dollars, the architect initiated a study of the wind distribution around the Stata...

Cross Ventilation in a Building

The design team was requested to design three mid-rise buildings for a residential building development in Shanghai (Figure 11). Since wind around the buildings is the driving force in cross ventilation, this investigation involves the simulation of indoor and outdoor airflow by CFD. In order to study the impact of surrounding buildings, the computational domain for outdoor airflow should be sufficiently large (e.g., an area of tens of thousands to a million square meters). Due to the...

Infiltration

The infiltration rate for any given building is primarily a function of construction standards and the wind speed outside of the building. Without reductions in infiltration, the effect of the other specifications is not as significant. Placing taller buildings on the winter upwind side of the project could reduce the infiltration rate by reducing the local wind speed around adjacent buildings. Low quality construction, low insulation High quality construction, high insulation Figure 4...

Wind

During the summer months, the prevailing winds in Beijing are from the south (Figure 39a). The standard design of other neighborhood developments in the area are of uniform height, rectangular-shaped buildings laid out in rows, with the long sides facing north to south. This configuration does not allow winds to penetrate deeply into the developments as individual buildings block airflow from the north or south. MIT's proposal staggered both the height and the plan of the buildings, allowing...

Design Tools

Wind Energy Building

Traditionally, many architects predict the airflow in and around buildings by using smart arrows, as shown in Figure 3. Drawing the airflow correctly requires a rich knowledge of fluid mechanics. Unfortunately in many cases, the predicted airflow pattern can be completely different from that in reality. Furthermore, the smart arrows cannot give the wind speed, or at least the reliable air speed, which is an important parameter for evaluating the benefits of natural ventilation and outdoor...

Shading

Shading studies were performed in order to show that the new scheme provided the desired density number while still satisfying the winter sunlight code. Shading studies shown in Figures 43 through 45 demonstrate winter shadows at 9 AM, 12 PM, and 3 PM. Note that the proposed study had additional rows of thinner buildings. The buildings were arranged in this manner as a means to obtain better daylight access while also providing improved summer wind circulation. Figure 39a Summer winds the...

Passive Solar Building Design

Solar energy travels through the windows of a building, increasing the energy used by air conditioners and degrading occupant comfort. An ideal passive solar building minimizes internal energy use by optimizing its design to suit the annual path of the sun and the local climate. A primary goal in energy-efficient design for buildings in warm climates such as Shenzhen is that they must minimize solar heat gain during much of the year. Based on solar energy calculations for each window direction...

References

Natural Ventilation in Buildings A Design Handbook. James amp James Ltd., London. Allocca, C., Q. Chen, and L. Glicksman. 2003. Design Analysis of Single-Sided Natural Ventilation. Energy and Buildings, 35 8 785-795. Awbi, H. 1996. Air Movement in Naturally Ventilated Buildings. Department of Construction Management amp Engineering, University of Reading, U.K. Bottema, M. 1980. Wind Climate and Urban Geometry. Ph.D. thesis. Eindhoven University of Technology, Eindhoven, the...

Series I Simulations

Results for the first series of simulations are summarized in Figure 13, which presents the number of hours over the five-month simulation period when the indoor temperature falls into specified temperature bins a total of 3,648 hours . Results for each case will be discussed next. In addition to building-construction details, the base case is defined by the air-change rate and the schedule and magnitude of internal heat gains, both of which strongly affect indoor temperatures. We estimated a...

Acknowledgements Of A Green Building

The authors would like to thank the Alliance for Global Sustalnablllty AGS . The AGS was formed In 1994 by three of the world's leading technical and research universities the University of Tokyo, the Swiss Federal Institutes of Technology ETH and the Massachusetts Institute of Technology MIT . Slncethen, Chalmers University has joined the team of engineers that has developed a new approach to strategically addressing problems affecting the global commons. This project has also been made...