Louise Fowler-Smith, a senior lecturer at UNSW Art & Design and director of ILIRI proposed the idea of retaining rainwater in the walls of a structure for the purpose of recycling and utilising the water’s thermal mass after witnessing precious water disappear on the occasion of infrequent yet heavy rain at the arid zone research station at Fowlers Gap.
Assessment of the feasibility of this idea was sought in the hope that a design solution could be obtained and put into practice, originally for a future artist studio at Fowlers Gap (subsequently it was decided that it would be better implemented as part of the Broken Hill Environment, Art & Sustainability Hub (BHEASH). The purpose of the design is to achieve a comfortable living environment in the punishingly hot outdoor environment through the innovative use of a natural resource, water, and other basic engineering principles and materials such as recycled scrap metal left behind from the mining boom of Broken Hill. This effort is driven by the desire to reduce the use of poorly designed buildings in the region that require large energy wasting air conditioning systems.
The aim of the water wall is to provide insulation to the structure by using a natural resource. A viable solution would decrease the need for high energy expending cooling systems such as air-conditioning units, which can be witnessed on a large scale in the nearby town of Broken Hill.
The idea stems from previous research by ILIRI in areas of innovative solutions to sustainable living challenges. It has been found that in underdeveloped areas it is necessary to harness all of the natural resources and use them efficiently, as wastage is simply not a viable option. The ideas of recycling and harnessing the resources that the environment offers were largely drawn upon in this project, and tie in with ILIRI’s concept of Re-Cognising the land—that is, translating artistic vision into innovative ideas and practical applications in terms of the natural environment.
Optimally the design would allow the water to be re-used, however thermal mass calculations concluded that thermal mass insulation is only efficient when used to full capacity. For this reason the water in the walls will remain in the walls, and rainwater will be captured for re-use in an on-site detention system.
Calculations on the thermal dynamics of the water wall insulation show that a wall that is 450mm ‘thick’ with water optimises living conditions during hot climates by delaying the release of heat into the building and decreasing the amplitude of temperature variation between day and night periods. However, significant diurnal outdoor temperature variations are required for the thermal mass to work effectively.
Thermal mass is a major contributor to passive solar design, which is based on the idea of harnessing natural energy to limit people’s dependencies on mechanical methods of heating and cooling. Thermal mass itself relates to the capacity of a material to store thermal energy over extended time periods and through its storage ability, naturally modifying temperature fluctuations.
Thermal mass is beneficial throughout the year. In summer, it moderates the internal temperature by hindering the passage of heat through the external wall, whereas in winter, thermal mass absorbs the heat from solar radiation and re-radiates this stored heat into the home in the evening when it is needed. The latter is more suited to domestic use.
Thermal mass utilisation is best suited to regions with a large diurnal range, i.e. high daytime temperatures and low nighttime temperatures. The recommended temperature ranges are daytime maxima between 32 and 36°C and minima below 20°C. The low nighttime temperatures are then used to provide cooler indoor ambient temperatures the following day. Indeed, when used appropriately, thermal mass can act to regulate indoor temperatures around the average daily temperature.
Aesthetic: The idea of recycling and harnessing the resources that the environment offers were largely drawn upon in this project, and tie in with ILIRI’s concept of Re-Cognising the land.
By using a natural resource such as water to provide insulation and thermal mass to a building this project will enhance public awareness on alternative building practices that will enable less energy consumption for cooling and heating.
By using recycled material from the mining industry this project will enhance public awareness on alternative building practices that stress the value of recycling from local resources rather than shipping in new materials.
Innovation/risk (conceptual + technical): With the depletion of resources and the rising cost of energy, the world is looking towards sustainable alternatives. Renewable energy is derived from non-depleting and usually non-pollutant energy sources, contrasting with fossil fuels, which draw on finite resources.
The creation of new technologies is integral in transferring society’s reliance from fossil fuels on to other forms of energy. It is therefore important to explore methods that use sustainability—and are thus more accessible and environmentally friendly— and to integrate them into society.
In the buildings and services industry, environmental sustainability has become of growing importance. Currently, both residential and commercial buildings account for 40% of total global energy consumption. Indeed the energy efficiency of a commercial building is based heavily on the sustainable design of the building. Initiatives such as the implementation of sustainable materials, efficient waste management, and improvement to indoor air quality and heating, and ventilation and air conditioning (HVAC) systems are indicative of this shift.
The aim of this project is to find a solution for the sustainable thermal regulation of the proposed Environmental Art Museum in Broken Hill, NSW. As part of this sustainable solution, the design and use of “Water Walls”—an idea based on using the thermal mass of water to moderate internal temperatures represents an innovative solution.
In keeping with the sustainability and community involvement aspect of ILIRI, the steel framing sections would be sourced using scrap metal from the local scrap yards in Broken Hill. This allows the local mining companies the opportunity to contribute to the materials of the structure, as a means of rehabilitating the environment, which suffers at the hands of their works. By offering the Water Tank House the waste metal that the mines would customarily scrap, the mining companies would be seen to be giving back to the community.
A structurally sufficient steel frame was designed to secure the water bladders in place. The design considers the various loads which the wall is subject to, and satisfies the resulting design actions from these loads with regards to both strength and serviceability (deflections). The design positioned the structure itself beneath a large awning, which serves the purpose of rainwater collection and also provides shade to the external façade, in order to prevent the water walls heating up via heat transfer in the steel connections.
Several architectural recommendations regarding glazing, curtains, roof drapes and standard insulation techniques have been studied and discussed in an effort to achieve a highly efficient structure in terms of minimising the fluctuation of internal temperature.
Artistic merit: The idea of recycling and harnessing the resources that the environment offers were largely drawn upon in this project, and tie in with ILIRI’s concept of Re-Cognising the land.
Audience Engagement: The proposed Broken Hill Environment, Art and Sustainability Hub intends to educate and inform the public of environmental issues and sustainable living. The building that will house the museum—through its water retaining walls— aims to act as an example of sustainable living, while its exhibits will display the ideological, information and technological transitions needed to achieve sustainability. Since it is itself a showcase of sustainable living, its presence and content seeks to make people aware of current problems such as the global issues facing the planet, the consequences of no action and the individual changes that can be made to achieve a sustainable existence.
This project aims to activate debate about alternate methods of building in the arid to semi arid zone of Australia. It focuses on the importance of thermal mass in the reduction of the use of energy consuming heating and cooling systems.
Economic: The water wall provides insulation to the structure by using the natural resource of water, which is free. This also decreases the need for high energy expending cooling systems such as air-conditioning units or heating in winter.
Australia’s growing population and continual negligence of environmentally sustainable lifestyles has placed increasing strain on the natural environment.
The use of natural resources must be re-evaluated in order to create a standard of living that incorporates and embraces self-sustainable innovative techniques. Such techniques would seek to minimise waste through efficient use of natural resources, and would include procedures such as recycling, re-using and reducing. This project addresses these needs. The wall design will incorporate local scrap materials as a means of recycling, and additionally will harness captured rainwater to fill the wall cavities as a measure of efficient use of natural resources.
Furthermore the project will involve an inter-disciplinary approach with the local community to create awareness of a mutually beneficial approach to environmental issues.
This project came about as a result of a conversation between Louise Fowler-Smith and Professor Don White, from the School of Engineering at the University of Sydney. The feasibility of capturing the infrequent, yet heavy, rainfall at the arid zone research station at Fowlers Gap within the walls of one of its building was the main topic of conversation. Water is stored in large open dams at Fowlers Gap, and dams are similarly used to hold the main water supply for Broken Hill, even though it is well known that 20% of the water evaporates every summer. Fowler-Smith believed that there had to be a better solution for the storage of water in this environment. With the awareness that the majority of people in Broken Hill live in corrugated iron houses, necessitating large air conditioners for the summer heat, she was also interested in exploring alternative methods of building.
Fowler Smith has been working on this project for some time now and in 2014 the project was still at the proposal stage, however grant funding was being sought through an Australia Council Linkage Grant to explore the remediation of old mine sites, with the BHEASH acting as a test site for innovative ideas that demonstrate alternative ways of remediating and living on these sites. The design could then be taken to other remote communities in Australia.
- Bucalina, Bonar, Chris Borg, Benjamin Collins, Christopher Maher. Advanced Engineering Project: Feasibility Study for Water Retaining Walls. University of Sydney, Australia, 2008.
Mehta, Natasha. The Design and Use of Water Walls for Sustainable Thermal Regulation in Buildings. Hons. diss., The University of Sydney, 2011.
Imaging the Land International Research Initiative. http://www.cofa.unsw.edu.au/research/research-units/iliri (accessed November 20, 2013).
Video documentation of The Water Tank House: http://www.niea.unsw.edu.au/media/iliri-water-tank-house