21 January 2015 - Technology devised in Christchurch to help improve comfort in outdoor urban settings, is now being used in the Middle East for the exact opposite reason from that originally intended - to keep people cool in the scorching desert environment, rather than warm in New Zealand’s more temperate climate.
Engineering firm Aurecon has created an urban comfort assessment model where they are able to predict the combined influence of wind, sun and shade, sun angle, solar radiation, temperature and humidity in outdoor areas in and around urban precincts to give an overall assessment of comfort across an area.
Aurecon has already undertaken urban comfort assessments in Christchurch of The Terrace entertainment and office development on Oxford Terrace and the new central Bus Interchange, and is now commissioned to undertake a study on a proposed shopping complex in Abu Dhabi.
Mike Green, Engineering Meteorologist for Aurecon, said that there was a certain irony in that the modelling tool developed to identify and mitigate against cold areas, was now being used on the other side of the world for the opposite reason.
“Spurred by the opportunities with the redevelopment of Christchurch following the earthquakes, we created an urban comfort model that could help in the design of a building or larger precincts and its surrounding areas to indicate the level of comfort people would experience when visiting that area.
“It gave us the ability to quantify changes in comfort levels should mitigation techniques such as changing the angle of the building or if different types of landscape architecture is undertaken.
“When we were creating this model we were focusing more on protecting people from the cool winds often experienced in New Zealand, rather than the searing 50ºC plus temperatures experienced in the Middle East and the application of our software in relation to an outdoor shopping centre,” he said.
The brief from the Middle East developers to Aurecon was to know whether, by introducing shading and mechanical cooling, they could make outdoor conditions comfortable during the hottest times of the year, which meant having conditions that felt more like 38ºC rather than 50ºC.
The shopping centre is designed to create an outdoor, open-to-the-sky retail/dining destination, replicating the “souk” atmosphere in a modern aspect. It will accommodate a total retail area of around 30 000m2 and will be divided into three modules of approximately 10 000m2.
“Our solution is a mixture of building angle and positioning, landscaping considerations supported by mechanical solutions such as retractable shading and chilled waterfalls and walls.
“The pedestrian streets in the mall are oriented in a north/south direction to maximise shading from buildings, the piazzas are in a rhombus or diamond shape also to achieve maximum shading, and a retractable shading system installed above each piazza are needed to provide the amount of sun protection in the hot season.
David Haylock, Mechanical Engineer with Aurecon, also located in Christchurch, said that they have incorporated several methods to cool the outdoor areas such as cooled walls and floor slabs, and it was found that with chilled water fountains we could get lower temperatures without the need to worry about condensation. The fountain will be chilled to around 7ºC and will provide a film of water over the face of a perspex waterfall.
“The water will provide a high level of radiant cooling as well as evaporative and convective cooling,” he said.
The pedestrian main streets, oriented in their north/south direction, open on to the large piazzas. Cafes and restaurants can be extended to the exterior sidewalks, allowing outdoor dining with scenic views to the chilled water features that will provide a sensation of coolness and tranquility to these places.
Mike Green says that anywhere there is a new development that involves enjoyment for people are great opportunities.
“If, in the design process, we are able to identify and create areas that people find comfortable, they are more likely to be more attracted to that particular area and will stay longer. If you are in retail and hospitality, you want to know where these places are or how to create them. More people, staying longer, generally means more business, more turnover, more profit, greater success.
“We can help developers and architects identify these areas in the design stage,” he said