Dr Greig Paterson, Design Manager for Interdisciplinary Design & Research at Drees & Sommer Middle East, recently gave an interview on the topic of increased demand for air conditioning in warm climates, with a focus on the Middle East. He covered topics like how innovative design combined with vernacular architecture principles could improve efficiency and increase wellbeing for future-proof and sustainable cities.
What design elements can be incorporated into buildings in the Gulf region to reduce the demand on air conditioning systems?
When considering ways to improve efficiency and increase wellbeing in any region in the world, it is always useful to learn from the vernacular architecture of the past. Vernacular architecture is a style of building that is indigenous to a particular region; designed to suit their context using passive design techniques and local resources.
In the Gulf region, there are variances in traditional architectural approaches, however some common features include ample shading; a glazing to solid wall ratio that allows for natural light while reducing unnecessary solar heat gain; the use of local materials that are often light in colour, reflecting the sun’s energy back to the atmosphere; the use of vegetated courtyards, which provide shade, allow for natural air movement, and provide private/semi-private outdoor sanctuary spaces; and the use of passive ventilation methods such as wind catchers. From an urban scale, it is beneficial to cluster buildings close to one another to create self-shading, both for the buildings and the surrounding walkways.
Certain flagship projects, such as Masdar City, have showcased sustainable elements of building design, such as greater use of shading. Is there much sign that such sustainable approaches are being adopted more widely, outside of such eco-cities? Are there any good examples that you could highlight?
Shade plays a vital role in sustainable buildings, both in terms of blocking the sun’s energy and in enabling good quality daylight into buildings. Two examples of buildings in the region that adopt innovative shading are the Al Bahr Towers in Abu Dhabi and King Fahd National Library in Riyadh. The twin Al Bahr Towers opt for a dynamic approach, whereby an array of origami-like sun shades are programmed to ‘bloom’ when the sun path aligns with different areas of the façade and contract when there is little or no sun exposure. This protection from direct sunlight allows the glazing to be much more transparent than is typical in the region for high rise office buildings – resulting in improved daylight as well as energy efficiency. King Fahd National Library also adopts an innovative shade strategy, but this one is static. White, three-dimensional, textile membranes act as sunshades while allowing plentiful amounts of daylight in, creating a protected and pleasant space to read and study.
Moreover, on many of the recent developments and design competitions we have been involved in, there is a welcomed growing trend towards wellness, whereby the quality of the environment for human beings, both inside and outside, is the focus. This manifests itself in the desire for high quality daylight, as previously discussed, natural air movement, and comfortable ‘microclimates’ in outdoor areas so that people can enjoy these spaces for al fresco dining, family strolls and outdoor activities such as cycling. This trend is welcomed as it is a move away from the post oil discovery years of creating buildings that are designed in a highly glazed, western ‘international’ style, that act as artificially conditioned ‘islands’ with little consideration to the surrounding context and overall psychological and physiological needs of the occupants.
What would it require for sustainable approaches to design to be used more commonly? Is it a question of building regulations or are there other factors that could promote sustainability?
Cost is a major driver for any large investment and buildings are no exception to this rule. However, all too often, it is primarily the upfront capital costs of a building project that ultimately determine what methods, technologies and materials are finally adopted – with many of the aspirations laid out in the vision design stage removed by means of ‘value’ engineering when in fact these features make economic, as well as environmental, sense if considered over the life of the building. What is required is an understanding of the whole life cost of buildings and the built environment in order to move towards more sustainable solutions. Over the course of 30-40 years of a building’s life, the costs to operate a building – operational costs – can often account for up to 80% of the overall whole life costs, with capital costs making up the remaining 20%. By predicting the impact that design decisions have on the whole life cycle costs of a building, not just the capital costs, sustainable buildings can win the financial argument as well as the moral, scientific and wellbeing one.
Given that air conditioning is being adopted more widely in developing countries such as India, do you think it's inevitable that total global energy consumption from air conditioning will continue to increase, or could such increases be cancelled out by improvements in efficiency and the increased use of alternative methods of cooling?
As incomes in developing countries rise and more people migrate towards cities, as is the current trend, there is almost certainly going to be an increase in air conditioning use in the coming decades. This increase in air conditioning is driven in part by the desire for comfort, however other factors play a role. As household income increases in developing nations, so does the desire for appliances, such as refrigerators and televisions. These items generate heat, which, combined with the high ambient temperatures in many of the places where this trend is occurring, means that the need for air conditioning increases. Moreover, the rejected heat from air conditioners make cities hotter than rural areas with the same climate, thereby increasing the need for air conditioning – this phenomenon is known as the urban heat island effect.
These factors make it a challenge to reduce the upsurge in energy required for an increase in air conditioning. Nonetheless, there are factors that can improve comfort, wellness and energy efficiency, despite this growing trend. These include greater education to communities and developers, worldwide, on the benefits of designing with sustainability and wellness in mind. By adopting more vernacular techniques, in new and innovative ways, natural ventilation can more often be utilised during the cooler months of the year, which both reduces energy consumption and increases wellness, when external conditions allow. Furthermore, simple solutions such as ceiling fans contribute greatly to thermal comfort at a fraction of the energy cost of air conditioners. These systems may not be suitable to replace air conditioners in every instance, however they can be used as an intermediary step, which will reduce the need for air conditioning throughout the year.