Adaptive buildings in sight

By Sylvain Comeau

Radu Zmeureanu is setting foundations for the building designs of tomorrow.

Zmeureanu, a professor in the Department of Building, Civil and Environmental Engineering and director of the Centre for Building Studies, is a leader in the new but burgeoning field of sustainable buildings.

“Sustainable development was introduced as a concept in 1987 by the United Nations. Sustainable buildings are an outgrowth of that concept, and people in the field believe that this is the future goal for buildings.”

While building design has incorporated increasing energy conservation and efficiency over the years, truly sustainable buildings will set a higher standard than in the past.

“[The concept] means not only energy efficiency, but it’s also a reduction of the depletion of natural resources: energy and materials. It incorporates costs, emissions, and energy use over the entire life cycle of a building,” Zmeureanu said.

The theory of sustainable buildings involves considerable redefinitions, and a building’s life cycle is no exception.

“The life cycle now starts from the moment we start to drill for and extract raw materials, to the transfer of the materials, the manufacture of the components, the construction on the site, and, after 40 or 50 years, to dismantle, demolish or recycle the building.

“This gives us a different perspective, a long term view; we are really looking at the future of the planet, in terms of the depletion of natural resources.”

Zmeureanu emphasizes that the concept is not yet a reality, and that a totally sustainable building is “the goal, the dream. It’s like a philosophical concept; we are not yet there.”

With his graduate students, he is pursuing a variety of research avenues leading to these goals.

Grad student Wei Min Wang, under the supervision of Zmeureanu and Hugues Rivard of École de Technologie Supérieure, is developing a “genetic algorithm,” a computer tool for simulations that can be used by building designers to optimize sustainability.

“A design solution is like a chromosome; in the same way that two people can procreate to produce new generations, we can combine solutions in the genetic algorithm to generate new ones. The algorithm selects among the sea of design solutions according to the criteria of sustainability, to minimize life cycle costs and environmental impact.”

In another project that may take a central role in future building designs, Zmeureanu and grad students Xinyu Wu and Yaolin Lin are defining indicators of sustainability.

“Presently, we are trying to design sustainable buildings, but we don’t know very well how to evaluate sustainability. There are hundreds of indicators, but they are not recognized and suffer from many limitations and mistakes. Therefore, we are trying to evaluate these indicators based on fundamental thermodynamics; universal laws.”

The focus on thermodynamics is a new approach, setting aside issues like cost, which are subject to fluctuation.

“We are trying to provide standards that are neutral with respect to the costs of today. Our indicators will not be affected by social or geopolitical situations like wars, which can distort the prices of materials.”

Thermodynamics are first principles of nature, for example, exergy.

“Exergy is what you can extract, theoretically, from any source of energy. Energy cannot be destroyed, just conserved; that is the first law of thermodynamics.

“Exergy, however, indicates the reduction of quality of energy; you can destroy the quality, therefore exergy can be destroyed,” Zmeureanu said. “It is very important to see how you destroy the quality of an energy source. If building designers find ways to minimize the destruction of exergy, such as by using alternative energy sources, that means less depletion of natural resources.”

Zmeureanu and others in his field believe that the theory of sustainable buildings will eventually take the form of a new holistic design called adaptive buildings.

“We can’t reduce energy use, but we can react better to changes in the environment. That will be the whole point of buildings that are self-adaptive, like an organism. These will be modelled after nature.” Continuous commissioning will be a key to adaptive buildings; the process will mimic the adaptability of the human body to climate conditions.

“Continuous commissioning means to have sensors everywhere in a building: the building envelope, heating and ventilation systems, and so on. These sensors will collect data continuously, like the sensors we have on our skin. It will send this data continuously to the main server — the central computer, like our brain — and the computer will decide what actions need to be taken, and where. This is [what is meant by] adaptive buildings.”

Zmeureanu is the head of a project aimed at paving the way for this kind of central building computer. The project is collecting data from the new Richard J. Renaud Science Complex at Loyola.

“We are collecting data on electricity use, hot and cold water use, energy consumed by fans and other units, etc. All this data will help us develop new models for assessing energy performance in this kind of building; a building with a large number of labs and laboratory hoods.

“The goal is to take a big step toward continuous commissioning, which is not only collecting data but efficiently and accurately analyzing hundreds of thousands of measurements coming in every minute. Therefore we are working on developing the software in the brain of tomorrow’s adaptive buildings.”

Zmeureanu’s research is funded by NSERC (Natural Sciences and Engineering Research Council), Natural Resources Canada and the EJLB Foundation. He presented some research results at a conference held Feb. 11 in the Faculty Club, organized by the EJLB Foundation and the Faculty of Engineering.