Transporting natural daylight into Masdar City’s transport system
As the world’s first zero-carbon city, Masdar City in Abu Dhabi must first minimise its energy consumption before looking to renewable energy. It’s a philosophy that has led to the largest-ever installation of Monodraught Sunpipes to exploit natural daylight.
Areas of the passenger transport system in Masdar City, Abu Dhabi, one of the world’s most sustainable cities, will be illuminated by a natural daylight environment created using Monodraught Sunpipes.
Sunpipe natural daylight systems were adopted as part of Masdar City’s Technology Roadmap, a programme that has led to a number of globally important innovations and the formation of key technological partnerships to minimise Masdar City’s impact on the environment. Monodraught’s contribution, an even more sustainable Sunpipe, was designed especially for this project.
When Masdar was announced four years ago Justin Carter of Edison Lighting (Middle East), Monodraught’s agent in Dubai, realised that it would be an ideal opportunity for Sunpipes. Following an initial approach, Monodraught and Edison were invited to review conceptual drawings of a natural daylight installation prepared by project architect Foster+Partners. The system features a glass-block arrangement designed to carry natural light from a ground-level podium walkway directly above the transport system, into an undercroft below.
Responding to an invitation from Foster+ Partners, Monodraught then proposed a bespoke Sunpipe design that not only meets the natural daylighting objectives of the installation, but also complies with the stringent sustainability requirements of the project. The resulting order represents Monodraught’s largest-ever project for Sunpipes.
Monodraught managing director Tony Cull explains: ‘We knew from the outset that virgin aluminium was not acceptable for this project. We therefore sourced recycled material specifically to meet Masdar City’s requirements without compromising the spectral performance.’ Using recycled aluminium reduces the embodied carbon of these Sunpipes without affecting their output.
Ross Palmer of Foster+ Partners elaborates: ‘It was important to enhance the overall experience for people using the transport system, and this is achieved with the Sunpipes, which bathe the space in daylight to create as natural an experience as possible. Aesthetically we were also interested in the connection between the undercroft and the spaces above so that people would be aware of the existence of the underground transport network.’
From the outset Monodraught worked closely with Foster+Partners to ensure that Sunpipes would create an effective, naturally lit environment and ensure that the use of artificial light was avoided as much as possible in the undercroft during daytime.
The project features two types of Sunpipe installations — a coffer design described by Foster+Partners as a ‘giant waffle’ and a simple flat slab. In both cases the Sunpipe is the same.
For the waffle feature, Sunpipes are fitted within 1.5 m-square coffers, allowing light from the highly polished Sunpipe tubes to reflect onto the sides of the concrete coffers. This simulates a lantern effect which, in the absence of the ceiling diffusers normally fitted to Sunpipe installations, diffuses the light entering the undercroft. The combination of direct daylight from the flat slab and diffused light from the waffle creates a realistic, naturally lit environment that fulfils the requirements of the original concept envisaged by the Masdar Institute.
A total of 449 Sunpipes have been installed in the first phase of the MIST (Masdar Institute of Science & Technology) project, to deliver natural daylight to the undercroft. Another feature of these Sunpipes is a new reinforced glass dome that replaces the familiar Diamond dome. The dome can withstand wheel loads of up to 28 t at podium level, where emergency roadways are closed to pedestrians but provide safe and easy access for fire tenders, ambulances and maintenance vehicles. The reinforced glass dome is 500 mm in diameter, and the reflective aluminium tube diameters are 450 mm.
A bespoke ceiling diffuser has also been designed to meet Foster+Partners’ aesthetic requirements for the undercroft concept. It is hoped that the new Sunpipe will be adopted as the standard throughout Masdar City, as well as other projects in the region.
In addition to the environmental benefits gained by replacing electric lighting during daylight hours, the special Sunpipes also significantly reduce heat gain and solar compared to traditional glazing and skylights, helping to create a more comfortable environment for passengers.
Justin Carter stresses that Sunpipe manufacture and installation are also sympathetic to the Masdar City project’s sustainability and recycling programme on site, which means that all waste materials, installation consumables such as tapes, packaging etc., in fact anything used on site, is channelled into the recycling scheme that is an integral part of the construction guidelines.
The cost benefit is equally impressive. At least 75% of electricity costs used for lighting can be saved during daytime using Sunpipes to replace electric lighting. In addition, considerable environmental and health benefits are experienced (natural daylight is known to combat SAD, seasonal affective disorder) due to the much improved environment.
Summing up, Monodraught managing director Tony Cull says that Monodraught and Edison are proud to be supplying and installing Sunpipes for what aims to be one of the world’s most sustainable cities. He says that lead times and the installation timetable for the bespoke Sunpipes on the prestigious project were extremely challenging, but both companies worked hard to meet the demanding schedule, with Edison fielding a team of six, installing up to 20 Sunpipes a day.
