November 15, Istanbul, Turkey
The view of Istanbul city from the Asian side offers a beautiful panorama, which is slowly being punctuated by the increase of high-rise buildings. Whether the classic Istanbul skyline is to be disturbed or enhanced is still not fully decided; time will tell. Our speakers this year at the Swegon Air Academy in this amazing city shared their experiences of tall buildings from Canada, Europe and the Middle East. The topic attracted the attention of partners from industry, building services consultants, architects, journalists, professors and students.
Vince Ugarów presented his experiences with the very early design of high-rise buildings in London and Abu-Dhabi. Implementing site-specific climatic conditions and the five steps approach, the design of a high-rise building is subsequently focused on the shape of the building, facade performance, indoor climate, infrastructure and available energy from renewable resources. The indoor environment is significantly influenced by proper design of facades using an appropriate thermal solution such as a triple-glazed ventilated facade, ventilated to the outside with internal blinds along with thermal mass in concrete panels. The expected energy consumption of a tall building can be halved by getting the facade right and properly dimensioning the indoor air system to match. In the near future as a result of EU regulations, the design targets will be compared to measured energy consumption in buildings for all newly built buildings. This will bring much needed transparency to the building sector, which needs feedback on how buildings are actually performing.
Vince discussed the controlled development of mixed-use, high-rise buildings in London which aim to bring life to the city at night by using public terraces on upper floors and shops on ground floors. In comparison, uncontrolled planning in Abu-Dhabi focuses more on orientation of buildings using self-shading through balconies and smart placements of entertainment spots in shaded areas without direct sunlight. And at the same time, the goal is to reduce energy consumption using thermal mass facades, district cooling and off-shore fields of renewable solar and wind power.
The questions from the audience showed their keen interest, especially about the building process of high-rise buildings and facade glazing. Just now in Turkey, triple glazing is considered expensive and the local building industry is in constant search for affordable solutions which bring plenty of daylight and secure good environment with comfortable operative temperatures and then look for energy savings. More questions were raised on the available renewable sources such as well-performing photovoltaic panels for building facades or remote solar and wind farms. In Vince’s opinion, and still a part of the building process to be seriously considered, on-site renewable energy sources is not where most attention needs to be given.
Vince went on to show that international architects understand the value of very close and direct cooperation between architects and engineers to achieve energy-efficient high-rise buildings. Vince ended his presentation with a note on the observed historic trends and that many high-rise buildings were actually built during the recession.
Chris Pal perfectly complemented Vince’s words, by sharing his practical experiences with mechanical systems in high-rise buildings in Toronto and Dubai. Chris mentioned that the main driving forces for the design of tall buildings such as climatic aspects, building regulations, the expectations of investors and clients, along with long and short-term thinking. In Dubai, it is preferred to have on-site water storage on the roofs with solar tanks, resulting in problems with circulation of hot water and limited access to cold water. In Canada, there is a great need for heating, which is supplied by gas or geothermal energy, in comparison with Dubai where there is no heating installed, but, in the case of cold weather, portable heaters are offered. In the denser populated regions of Canada, the use of free cooling with cold outside air through air-cooled chillers or using district cooling supplied from cool water from deep lakes is often employed. Central air extraction directly to the outside is a common solution for high-rise buildings, but is being replaced by control demand exhaust from kitchens, bathrooms and other humid areas. The solution for kitchen exhaust in residential housing has to deal with the accumulation of grease using an indirect central exhaust. The two of many options for cooling of commercial buildings using variable air volume are fan coils and chilled beams. The chilled beams are more favourable when it comes to human comfort thanks to their radiation potential and effects on thermal comfort. However, chilled beams require a reasonably well-made airtight, insulated facade, which is not always part of the local building culture. In these types of buildings in climates like Dubai, fan coils are often the choice, even if they are time consuming to maintain.
Chris ended his presentation with the statement that the quality of the facade of a high-rise building and the ability to control the internal heat loads are the key elements when choosing the best system from all various ventilation and heating systems.
The audience enjoyed and participated in the exchange of experiences from the seminar in Turkey which has helped to support the development of concepts for healthy and energy-efficient high-rise buildings.
Image: Vince Ugarów and Chris Pal by Swegon Air Academy