Future Cities Laboratory
© Worldizen / Flickr under Creative Commons license
Starting this September, two PhD students under joint supervision of Professors Ian Smith (EPFL) and Benny Raphael (National Universtiy of Singapore) will be participating in a major research program, the Future Cities Laboratory, to improve the environmental and economic sustainability of cities. Based in Singapore, they will contribute to research into the impact of the outdoor environment on the indoor climate of buildings and develop methods to exploit data from sensor arrays to improve the accuracy of numerical simulations.
The Future Cities Laboratory was launched one year ago as the first research program to emerge from the Singapore - ETH Center for Global Environmental Sustainability (SEC). Over a five year period, engineers, architects, and city planners are exploring ways to make cities more sustainable while at the same time making them more livable. One cornerstone of the program is the development of a simulation platform to provide input to city planners and decision-makers alike, to support them in their work. Better simulations, so they hope, will lead to more informed decisions.
The limits of simulation
According to Professor Smith, director of the EPFL's Applied Computing and Mechanics Lababoratory (IMAC), simulations will never be perfect, and those used today in designing civil engineering projects and analyzing built structures are often quite inaccurate. Assumptions and simplifications made in numerical simulations can lead to systematic errors, biasing their outcome. Incomplete knowledge of the systems and their interactions with the surrounding environment compound this problem. Scientists typically resort to laboratories that provide well controlled environments to reduce this error as much as possible. But today, thanks to technological developments, it is becoming possible to leave the lab and perform these studies in a real world setting.
The technological developments enabling this push are threefold: optical fiber sensors, increased computer storage capacity, and robust portable computing. Using optical fibers, temperature, strain, or displacement can be remotely sensed at a high resolution and with little drift. Data collected by the sensors can be fed into numerical simulations to tune model parameters and keep systematic errors at bay, thereby providing a more accurate analysis of the system under study.
Efficient cooling
About 30% of global end-use energy is consumed in households, and well over half of it goes to space heating and air-conditioning. Today, heating claims the biggest piece of this pie. As temperatures increase world-wide, energy demand for air-conditioning is likely to follow, slowly catching up with falling demands for heating. An obvious route towards urban sustainability would involve improving the energy efficiency of air-conditioning units. But what if buildings were somehow by design made less reliant on aritificial cooling in the first place?
Without considering the role played by the outer envelope of buildings, the EPFL PhD students will contribute to studies of the effects of solar incidence, wind patterns, and humidity on the indoor climate of Singapore's high-rises. At the level of individual neighborhoods, these factors are primarily influenced by the configuration of buildings. If the goal is to optimize urban design to make cities more energy efficient, then what quantities should be monitored, how should they be measured, and finally, what should be done with the data collected? In the very near future, these questions will be receiving the attention they deserve.