The ‘smart’ buildings improving the quality of life
The late Professor Michalis Dertouzos of the Massachusetts Institute of Technology (MIT) used to say that technology in fields like medicine, the environment and energy management is condemned to develop regardless of the cost and the price. Time will tell if this is the case. What is certain is that the fate of the human race depends on our reducing the pressure on the already overburdened environment. Dertouzos believed that inspiration, eccentricity and inventiveness were essential to progress. University research in the complex and expensive field of building climatization is constantly inventing innovative systems which enable the users of buildings to improve their own quality of life, attaining the right temperature and visual comfort, while improving the quality of life for many others by reducing air pollution. The new tool which, in combination with a range of other products, reduces the use of air conditioners and heaters and thus of pollutants, is the smart window pane. Choice of window panes Manthos Santamouris, professor of physics in the Building Environment Department of Athens University, told Kathimerini that the new photochromatic or electrochromatic windows, which have a low emission factor, are a new method which has succeeded in limiting energy loss from five watts to 0.5 watts per square meter over the past decade. This means a reduction of some 90 percent over a decade, and naturally implies decreased energy consumption. Smart transparent materials, such as photochromatic, electrochromatic and heat reactive window panes can regulate the internal temperature in response to external stimuli. Santamouris, whose research team has constructed such window panes, explains the process: Electrochromatic panes regulate their translucency by means of an electrical current, so that the right amount of solar radiation enters, heating the room to a comfortable temperature. Photochromatic panes work on the same principle, but with the difference that they adjust their color to provide the right amount of shade and the most comfortable temperature. Then there are aerochromatic window panes which regulate a gas they contain to alter their translucency. New heat retention technologies are equally interesting. There are new materials, such as highly absorbent paraffin, which retain and store excess heat that builds up in the building during the day and use it at night, or store it on sunny days for use in cold weather. With the help of research, industry has come up with smart systems for natural ventilation and shading systems that open and close themselves with the help of photovoltaic systems. Central energy systems In Europe, authorities have begun turning to central energy systems to supply hot and cold water to cities. These are a far better solution than air conditioners and heaters which increase energy consumption and pollute the environment, says Santamouris. A highly successful central heating and cooling system is already in operation in the Parisian suburb of La Defense. Users simply hook up to the system, which goes past every house or block, as they would hook up to the water or electricity supply. Tele-heating and tele-cooling employing advanced production based on natural gas or solar energy are the new energy-saving technologies employed in these central systems which can heat and cool entire cities at very low cost and with minimal environmental effects. The new systems make individual heating and cooling systems unnecessary. In Greece, the technology exists but capital is needed to bring the new systems into everyday use. Now that the energy market is being deregulated in Europe, there are private individuals and large investment companies that sell energy through third party financing. They might, for instance, come to an agreement with the owners of a building to fully equip the building with energy systems, without any cost to the owners, who will simply buy energy. Such a plan is being promoted in Greece, and may soon be voted on by Parliament. At the Olympic Village One example of the self-financing system, says Santamouris, is an offer made for the Olympic Village. A large European firm made a proposal to fully equip the village with a state-of-the-art energy system for the sum of 2 billion drachmas. But this did not get accepted, possibly because the authorities had no knowledge of the system and were unable to comprehend its potential, and because vested interests may have been involved. In the future, however, cities will have to rely on such overall energy systems, which may be the only way to tackle the problems of thermal, chemical and biological pollution. Glass towers are greedy energy consumers Low visual and thermal comfort are serious defects in a building. Over the past decade it has become apparent that numerous products, materials and systems have harmed the safety of interior environments, causing a huge rise in the incidence of childhood asthma and allergies. The rapid urbanization of Europe led to the construction of high-tech buildings that are greedy energy consumers. In fact, say experts, buildings are the largest energy consumers in the world. Buildings consume the equivalent of the world’s daily oil production, and construction is the premier economic sector in Europe, with millions of workers and a huge turnover. It is certainly worth trying to curb energy waste, since a 1-percent increase in GDP increases energy consumption by 9 percent, and a 1-percent increase in urbanization increases consumption by 2.1 percent. One of the culprits of increased energy consumption is the uncontrolled use of air conditioning. Until recently, explains Santamouris, anyone could buy an air conditioner in Singapore and sell it in Europe, where local conditions reduce its effectiveness by 30-40 percent. The EU, with active support from Greece as of next year, is establishing standards and grades for air conditioners that act as a guide to their quality and performance. Sixfold consumption Europe is still in the phase of building glass towers that stand accused of excessive energy consumption. A glass tower consumes six to sevenfold the energy consumed by a conventional building, operating at a temperature of 22C instead of the appropriate temperature of 26C. With a centralized energy system, the Public Power Corporation (PPC) could limit the power used by such a building and avoid the need for an extra power station. PPC wants to acquire the means for rational energy management, which would encourage architects and engineers to construct environmentally sound buildings, but there will be an adjustment period and the public must be informed.
