Saturday, 30 November 2013

Heliostats happen (updated)

There is obviously interest in heliostats.  While I have been a bit preoccupied with other things, and failed to add much new to my blog, the heliostat pages seem to attract the most readership.  So, here is a bit of an update.

I have now had the opportunity to visit the retail areas of Central Park, since their 'hard opening' some weeks ago.  The heliostat mirrors do not appear to be functional yet, so my initial impressions cannot advance our assessment of what they actually do, or how well they do it.  But some aspects of the design do become easier to understand, and therefore if one is so inclined, open to criticism.

The thing that immediately struck me was that there is a big difference between the architectural renderings of the key spaces, and the sensation of those spaces in real life.  The scale of both outdoor and indoor 'public' space is much less expansive that the renderings suggest.  But in particular, the sectional complexity of the shopping spaces turns out to be rather humble in its impact as you move around what is in reality a very small retail mall.

Even more disappointing is that when the heliostat mirrors are finally tracking a beam to the skylight at the top, it's hardly likely it will make a positive difference to the lighting of the central indoor space.  There is a significant 'diffuser' on the skylight: a glass bottomed pond.  The rippling water varies the transmitted light continuously at a rate far greater than the rate at which daylight normally changes.  Normally, one of the arguments for natural light as opposed to artificial is the psychological value of its variability.  But this arrangement goes far beyond the intrinsic subjective value of natural light as opposed to artificial.

I can't convince myself that this is a rigorous technical lighting decision, because of other issues with the general lighting quality.  So, for instance, on going inside the mall, one realizes that the highlighted portions of the interior will be significantly brighter than the adjacent areas, and to balance the user's adaptation levels, quite large amounts of permanent supplementary artificial lighting is required. That lighting is provided by some designerly chandeliers, which even on a cloudy day struggled to achieve any liveliness.  But wait, there is more.
Once one tunes in to the technical issues of the lighting, one questions the material finishes in a different way.  The distribution and modelling characteristics of daylight are everywhere hugely affected by the internally reflected component.  So it comes as something of a surprise that at Central Park there is a cute faux 'timber look', even down to the dark brown planked floor.  The colour and the material are very low reflectance, and literally suck out the diffuse reflections on which better daylight distribution would depend.  And to make things seem almost laughably inept, there are long walls finished in similar materials, taking up major portions of the places where a competent shopping mall would have had shop windows spilling their own light.
Genzyme HQ, Cambridge, Ma
I hate sounding unrelentingly negative.  But these few comments go to the heart of my recurring themes.  First, I have a pet project of encouraging people to actually look at the pretty pictures that accompany the spin doctors' press releases. When you do that, you see what I am describing, even in the official photographs of the opening of this aspirational shopping experience. Second, when you take the trouble to tease apart the principles of technical performance, you can more easily find positive precedents for inspiration.  In this case, for instance, the heliostat and reflective chandelier of the Genzyme HQ building in Cambridge Ma. is a much better technical solution to daylight distribution.

Back to the iconic cantilevered frame of the heliostat.  It is remarkably close in every way to the renderings, yet it too undergoes a strange perceptual shift as one walks into the site.  Closer to the buildings than the usual hero shots illustrate, the cantilevered plane closes up the normal sky view between buildings. It is a very counter-intuitive sense of intimacy, and on balance wasn't a good feeling. Certainly from below, the experience is not exhilarating, though it may well be for those privileged to access it from above.  Some time soon, I will take the trouble to photograph the views that don't yet appear on the internet..  But to be fair, I am waiting for the heliostat to be commissioned.  When that happens, I will top up this post.

Other heliostat links:
A nice little review article on DesignBuild Source by Justin McGar here.

A more recent press release, with the image of the whole heliostat that actually includes the motorised primary reflectors on the roof of the shopping centre building.  Click here for the article.

I dread to think how inconvenient it would be for residents looking down if one or more of the lower mirrors' tracking goes awry.  But that is just my paranoia about depending on moving parts!


Anonymous said...

The lighting of the mall definitely appears as if it will rely heavily upon the large cantilever heliostats. However, since the cantilever is such an iconic feature of the building, it is almost certain that the owners will use it to market their building. Whether or whether not such activities will be detriment to the natural lighting provided by the heliostats is the question. Already, there are art installations on the cantilever. A lighting installation called the “Sea Mirror”, or “Miroir de Mer”, has already been installed on the heliostat by French artist, Yann Kersale. While this permanent installation may not currently affect the performance of the heliostats, future installations may do so, especially if they are fitted into the heliostat system. This leads us to question; should the entire building rely on the heliostats for natural lighting?

Perhaps Jean Nouvel should have had taken a note from Genzyme HQ building and have multiple ways of capturing natural light. In addition to the heliostats, the Genzyme building also feature specialised blinds that reflect light onto the reflective ceiling, an adaptive light wall and 768 prismatic planes that further enhance the distribution of natural light redirected from the heliostats. Maybe Central Park could use some of these features, especially the prismatic planes, which could potentially double up as an art installation, further improving the aesthetic appeal of the building and the evident lighting problems.

Genzyme HQ Building Strategies

Sea Mirror Installation

Jonathan Yip said...

From my visit to One Central Park and viewing the East tower from the open public garden down below, the building with its cantilevering panels appear rather unusual and bizarre to me as if it was sliced by a large mirrored blade across the top floor and got wedged in between and in turn precariously left hanging on the end. However I certainly find it very compelling and intrigued by its functionality. As beautiful and stunning as it is, one will question the feasibility of the new system. While walking down Broadway street and admiring the building, I caught myself questioning what happens when the plants on the facade die? How do people clean the mirrors? Will it all work in the years to come?

Despite all the questioning, what really caught my attention was the vertical green garden that hangs along the entire façade of the apartment. The vertical green façade is certainly an impressive and eye catching feature of the complex that offers quite a dramatic contrast to the neighbouring buildings. I think the building’s incorporation of hanging gardens is a huge step in sustainable design and green living especially inspiring in the way how they use “revolutionary symbiotic planting” for its façade that is watered by the site’s blackwater recycling infrastructure1. I was awestruck to see something like this for the first time as it is something only commonly seen in photorealistic architectural montage and not so much in reality. Not only is it pleasing to look at while walking down Broadway street as I’ve experienced it myself but it also act as a lush addition to the cityscape or as Bertram Beisssel beautifully delivers: “A flower for each resident, and a bouquet to the city.”

In regards to my previous question of about the management of the hanging plants, architect John de Manincor from University of Queensland (Architecture Australia, May 2014, Issue3) has answered that question for me in his article: “The plants will live as long as the residents want them to” quoted from Dodd. If the residence as a whole finds the plants costly or unmanageable, then votes can be made to remove them.

From my personal opinion, the protrusion of the panels does not fit harmoniously well with the building towers which I think could perhaps be implemented in a different way. Perhaps attaching the mirrored panels along the vertical façade of East Tower which then directs light down to the pool (not sure if that works)? In terms of overshadowing, I feel concerned to the people who will live or currently living right underneath the panels as it is in endless shadow. Without the panels, at least one can still see clear blue skies. If I were the resident living underneath the panels, I’d rather enjoy looking up to the sky than into glaring mirrors or to the stars instead of 2880 LED lights at night. In general, the cantilevered reflector panel in my opinion is a cumbersome approach of providing light onto communal gardens and the city’s public domain which seems to be worked a little too hard and possibly a superfluous and elaborate approach to achieve solar gain down to the retail podium. As already clearly pointed out by architect John de Manincor from University of Queensland: “the mirrors do not reflect light into any dwelling: without them, 70 percent of dwellings receive the minimum three hours of direct sunlight between 9am and 3pm midwinter required by state planning controls.” Why go through all that when minimum requirement is still attainable without the heliostats?

Nonetheless, one can appreciate the architect’s audacious yet exciting experimentation with Australia’s first ever built sustainable residential-scale heliostats that act both as a dazzling spectacle for bystanders and an extravagant centrepiece for the building itself. It is only a matter of time that will tell whether the cantilevered heliostats will serve justice to the entire complex and the inhabitants.

Loh, JY said...

In my opinion, Central One is definitely set a milestone for the “green architecture” phenomenon in Sydney, given that the use of plants on the facade and also the quote mentioned above by John, “The plants will live as long as the residents want them to” has given a very strong impression towards the green approach. then, by looking at the cantilevered heliostat, which is visually striking, also the icon of the building delivers a promising function in reflecting sunlight. However, I think otherwise, although the initial approach may be good and is about the reflection of natural lighting but several issues arise such as will it work as it intended? What happen if it fails? How to carry out the maintenance for the heliostat? Isn’t it blocked the view of the residents?

While the biggest question I may ask is still, there are other ways to do for solar access but why this one? there may be an easier option like, switching between the position of the west and east tower, and adjust the height a little bit? But what I think the intention behind the heliostats are probably pointed more towards creating an iconic landmark on the map of Sydney and also introducing a new alternative in response to the solar access issue although like what Steve mentioned in the blog entry above, that it doesn’t really works out perfectly but nevertheless based on my previous experience visiting the mall, the effect of the reflected light can still be identified especially around the ground-basement level elevator.

By looking from a larger picture, the architect’s exciting approach really deserves a big round of applause for the building’s aesthetic, approach and also contribution to Sydney’s skyline and aim towards a sustainable city. While both the green facade and the heliostat emerges into the spotlight. Although at this stage the heliostat are still not perfect and seems to be in a experimental stage but nonetheless it opens up to endless possibility sets out as an important precedent to the future of architecture.