(upbeat music)
- This is the Flower Dome in Singapore,
and it holds the Guinness World Record
for being the largest glass greenhouse in the world.
And it's different than most.
In fact, the design is backwards.
Most greenhouses aim to capture and contain heat,
letting you do things like grow vegetables and plants
that wouldn't normally survive in colder climates.
But here, things are different.
Singapore is based on the equator
so conditions outside are hot and humid.
But this project aims to showcase plants
from around the world,
from Mediterranean climates through to arid dry conditions.
So in this case,
the goal is to keep the hot, wet air outside,
keeping things inside to around 22 to 25 degrees
and as low as 16.
And here's how they do it.
These structures are part of a larger project,
Gardens by the Bay.
And there are two greenhouses.
The first one, Flower Dome,
aims to recreate springtime Mediterranean conditions.
So it's mild and dry in the day and cool at night.
The other one,
Cloud Forest Dome,
aims to recreate mountainous conditions.
So it's humid,
but also relatively cool.
These buildings were constructed on reclaimed land
and they sit alongside other icons,
including the 50 meter tall
concrete infused steel super trees.
And this is clearly an ambitious project
showcasing hundreds of thousands of plants
from every continent, except Antarctica,
and the buildings are just massive.
This is an ambitious project
costing hundreds of millions of dollars.
The building itself faces some pretty extreme conditions.
It's located on the coast
so it faces some high winds and typhoon rains.
To cope with this,
there are these 28 ribs,
and what they do is they deflect the wind
and give it structural support.
To improve the efficiency of the design,
the 3300 glass panels were optimized
and used in a repetitive pattern.
That makes construction and maintenance easier.
To achieve this final design,
they created six prototype greenhouse systems.
They then used a series of active and passive controls
to ensure the cooling.
The challenge for designers
was how do you create a greenhouse
that doesn't experience the greenhouse effect?
Letting light in but not getting too hot.
And here are three things which really impacted the design.
One of the most important design features
was the glass that was used.
The engineers used specialized double glazed glass
with a layer of low emissivity,
low-E coating applied to an inner layer.
And that reflected most of the infrared light.
The second layer was then laminated glass,
and that reflects most of the UV light.
All up, this resulted in 65% of the light passing through,
but only 35% of the heat.
And this was the biggest factor.
As you can see,
it's incredibly bright inside,
reaching the target of 45,000 lux,
which is a unit of brightness.
And that compares to an office,
which is normally 500.
And it looks great.
The buildings also use a cooling system,
and an important ingredient is desiccate.
Now, if you bought electronics,
you might have got those packets that say do not eat
with a silica gel.
That's a type of desiccate.
What that is is it sucks moisture out of the air.
Now, in these buildings,
they use liquid desiccate.
10,000 liters of it is sprayed through the hot humid air.
What happens then is that it takes the humidity
from around 80% down to 30%.
The dry air is then pumped past some cooling coils
and then pumped into the greenhouse.
Now, an important design feature
is they do this at a very low level.
So it's kind of included in the concrete
and through the vents.
Taking a lot of the humidity out
really improves the efficiency of the system.
By having the cool air down the bottom,
it means that the hot air can continue to rise.
And then, with vents at the top,
that's opened and the hot air is vented out.
Even though these systems were used,
it was found that in direct sunlight at the peak of the day,
it could be so hot that it could damage the plants.
And the solution to this was a good old shade cloth.
The building has an automated shading system,
and these triangles unfurl.
They're around seven meters by 10 meters,
and they'll automatically go out when it gets too hot.
And what that means is all of these plants
that wouldn't normally be able to survive in Singapore
can survive and thrive.
And due to the regulated conditions.
some of them actually bloom
a lot more than they normally would.
Normally, it would be once or twice a year,
but being able to regulate the conditions
means that a lot of these plants
stay in bloom all year round.
(upbeat music)
That makes this a wonderful place to check out the plants
that admire some impressive engineering.
I'm Julian O'Shea,
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