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Thu 17 Jun 2010 04:00 AM

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Tech yourself

Somfy's Abdo Aoun expects new technology to help fuel the green building revolution.

Tech yourself
Abdo Aoun, projects, business and specification manager at Somfy.

Somfy's Abdo Aoun expects new technology to help fuel the green building revolution.

It wasn't so long ago that buildings able to respond independently to their surroundings would have been the domain of sci-fi movies, but the development of bioclimatic facades is bringing this idea one step closer to reality.

Traditionally used in Europe to retain heat, bioclimatic facades - which move to provide shading in response to the position of the sun - are being used to reduce solar gain and energy usage in some of the region's newest buildings.

Somfy develop the systems that allow the technology to work, as well as the motors for automatic blinds and shades. Abdo Aoun, projects, business and specification manager, spoke to Middle East Architect about the tech revolution. Bioclimatic facades seem to be a relatively new phenomenon, can you explain how the technology has developed?

"People have been using screen fabric to reduce glare for more than ten years. The blinds reduce glare and filter light, so you don't have the contrast on your computer screen, you can work and you are protected from the UV and the sun. After that, the industry moved towards using motors and a switches and a remote control, so that people didn't need to get up and pull the blind. What we've done is move this on even further, automating the blinds so that when the sun hits the glass, whether there is somebody in the office or not, the blind will go down." Can you give us an example of a typical bioclimatic façade?

"The kind of façade you need depends on how much you want to reduce energy consumption in your building. If you're happy with a solar gain factor of the building of 25%, for example, then you are better installing an automated shading system internally. But if you need more, then you need to think about positioning the shading system outside - and in a high-rise building you need to think about how to protect it from the wind, the rain and the dust. This is why we are developing the concept of the double skinned façade. This is a double-glazed façade with a cavity in the middle, and a venetian blind inside the cavity. The blind is inside, but in thermal terms it is external and therefore you have a solar gain factor below 12%, I assume, we haven't done the calculations yet."

That's pretty high tech.

It doesn't have to be. In a hotel, for example, you might go for an internal shading system. This is used to open and close the curtains. When the guest leaves his room the curtains automatically close. We have studies that show that this reduces the cooling costs by between 10 and 15% in the room. Imagine the cost saving in a hotel of 300, 350 rooms, all over the year, at a 60 to 65% occupancy. It's a lot of money for both the developer and the operator.

What other benefits are there to bioclimatic facades?

"Having a blind to react automatically to sun orientation reduces solar gain inside. If you take this into account from the beginning, in the design phase, it has a direct effect on downsizing the HVAC system and reducing cooling demands. If you synchronize it with a lighting control system then you have very significant savings in artificial lighting and the internal heat gain that is produced by the lighting fixtures. Another benefit has to do with well being, comfort and productivity. A lot of strategies show that people are happier depending on natural light instead of artificial lighting. Studies in hospitals also show that patients' recovery period shortens if they have a connection to the outside.

What is the hardest thing about persuading people to install this technology?

"Our challenge is presenting a business case, or an investment case, because the first thing that comes into a client's mind is: ‘OK, I'm installing this technology but how can I make the benefits tangible for me? What is the payback period?' and so on. We have to show the economic benefits, the cost benefits, to the developers and the return on investment. This is not such a problem at the moment because more and more developers are looking to have their building LEED rated and abide by regulations. Developers also have more need to differentiate themselves with energy saving and comfort creating measures. These are the top selling arguments to investors and to end users, especially in terms of natural light and reducing AC."