Quarter

Juintow Lin

PROJECT DESCRIPTION

This project was centered on the design of several mid-rise buildings for the Taidong Residential Quarter in Shanghai. The design was a collaborative effort of MIT's Sustainable Urban Housing in China Group and Tongji University's Construction Engineering Department and Architectural Design and Research Institute.The process was informed by a number of design and technology factors, including the results of energy studies, urban design concepts, as well as daylighting and ventilation studies. The primary goal of the design was to minimize the energy use of mechanical equipment and resultant costs through the use of improved building standards and energy-efficient details. Design decisions were made using guidelines from the findings of daylighting, ventilation, and energy studies that analyzed various architectural schemes and features. In addition, every effort was made to make comfortable and livable spaces that were unique to the typical landscape of Shanghai's urban development.

ENERGY STUDIES

The project began with a series of energy simulation studies conducted to inform architects how to design with an understanding of technologies and architectural features affecting the energy use of a typical residential unit. These energy simulations were created using the DOE-2 building energy simulation program (AEC 2006). The program performed a dynamic energy balance at each hour of the simulation period, accounting for heat flows across the building's exterior surfaces, heat gains from solar energy, lights and equipment, and heat storage in the building structure. It computed indoor temperatures when the building was not conditioned, and heating or cooling loads when equipment was used to maintain aspecified indoortemperature.Simulations took into account the building geometry, equipment, materials, surroundings, occupants, and other details that affect energy usage. These simulations were performed using natural ventilation with airflow of five to ten air changes per hour (ACH); air-conditioning was used to maintain comfort conditions when natural ventilation was not sufficient. In the CFD studies presented later in this case study, the airflow was estimated at 16 to 40 ACH, so the estimated impact on energy should therefore be considered conservative. In addition, the program used hourly weather data for Shanghai (Figure 1) to determine the energy usage for each given hour for the specified condition of the building.

The simulations were performed in two groups. The first set, called "baseline parametric simulations" included only single feature upgrades versus the baseline case described in Table 1. The second set, called "combined feature simulations" combined a number of the best upgrades from the first set to make recommendations for the most appropriate design solution.

Due to the site conditions, including the east-west site shape and prevailing winds from the southeast, it was determined that the units were best suited to be oriented north-south. The baseline case used for all energy studies was therefore a duplex unit with only north- and south-facing exterior walls. East- and west-

One Year Typical Weather for Shanghai China Dry-Bulb Temperature

One Year Typical Weather for Shanghai China Dry-Bulb Temperature

Hours (One Year)

-Dry-Bulb Temperature ° C

Hours (One Year)

-Dry-Bulb Temperature ° C

Figure 1 Hourly outdoor dry-bulb temperatures for Shanghai; hours are indicated as hour of the year, from 1 to 8,760 (Source: EnergyPlus Weather Data 2006)

Building Component

Specification

Floor area

2 story, 7 m X 15 m

Wall type

30.4 cm concrete, no insulation

Window type

Single-pane aluminum frame

Window area

33.3% window-to-wall area

Overhang type

No overhang

Electric heat pump

10SEER/7.8 HSPF

Heating set point

20° C

Cooling set point

24° C

Ventilation

No ventilation

Table 1 Baseline feature specifications

Table 1 Baseline feature specifications facing walls, in addition to the ceiling and floor, were modeled as adiabatic. The results corresponded to a typical floor, and were not representative of ground-floor or top-level units. While such analyses were limited in scope, they served as an appropriate design springboard in terms of general building features with respect to the existing climatic conditions. The correct identification of such base issues early on in the design process was critical for many subsequent design development decisions.

Was this article helpful?

0 0
Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

Get My Free Ebook


Post a comment