. So, moving on to the Ela Green School , so
these are some of the images that you see of the school.
Owner of the Ela educational trust and we were the architects as well.
So, the built up area is around 86000 square feet location is in Chennai .
So, Chennai we all know is a very warm and humid climate.
So, we followed so, we did a truly integrated design approach where all the team membersl;
it could be the NEP consultants, the architect the electrical contractor the HVAC contractor
are.
So, this was a precast building; so, we had the precast contractor.
All of us had were on one platform, we sat and designed various parameters together
at the same table to get the best possible output.
So, this were our design strategies; if you look at the building envelope per say, we
did not want to go completely with DGU.
So, the building itself is designed such that there are a lot of shading pockets that are
created because of the form of the building.
So, therefore, wherever there was direct impact and there was a harsh impact DGU was opted
for and SGU wherever it, there was a shading component.
And if you see, we have used both wall and roof insulation.
This being a precast structure, it was easier for us to specify to the contractor that we
wanted our walls insulated.
Similarly the roof as well and roof also has not only the hollow core slab plus the insulation,
but also reflective paint.
So, what the reflective paint does is I do not know how many of you all have been
to temples even Tirupathi temple; there they would have painted , there would be white
paint near the black tar top road.
And why is that ? Because you cannot walk on the black road because it is going to be
extremely hot where is if you walk on the painted part of the road it you it is you
can still walk.
So, this is because this these are nothing, but high reflective paints which reflect the
heat of the surface and keep the surface of the road cool.
Similarly this is what we are trying to achieve on the roof as well .
And so, ventilation was another part of the envelope design which I will talk about
it on because this we did not wanted to be a completely air conditioned building.
Although it is air conditioned, we did not want to operate it as a completely air conditioned
building throughout the year because some parts of the year are relatively cooler.
And a primary goal again just as it would be with any envelope design is to make sure
that the inside is the closest to comfort zone without any mechanical systems.
So, that with that as the primary goal and the thermal comfort conditions, we back work
on the envelope design.
So, if you see this is one of the initial drawings of the project where we would
have done sketches; if you see we marked , you can see some markings here . So, these are
the initial concept design drawings of how we will try and bring in ventilation into
the building . So, this is later, on this is the final version
of the drawing after various iterations etcetera if you see all the classrooms are modular.
So, I can either convert this space into one whole library or I can have.
So, everything its modular, so you just starts its repetitive in nature.
So, that way we can you know kind of keep it flexible for future expansion growth incorporation
of technologies any of those kind of parameters.
And if you see we also created spaces here this pockets the purpose of these pockets
were so, the school building is basically a pre kg to a grade 12 building and grade
12 or the higher grades sixth, seventh, eighth and so, on are ok.
They can play outside and the harsh sun and they will they still fine, but what about
small children and we know we have more summer than rainy season in our climatic condition.
So, what we do is we wanted the tot lot areas to be shaded.
So, all the tot lot areas and the play areas for children to interact had to be shaded.
So, the building the entire planning was done such that we have these pockets of spaces
which would be shaded So, the building is again North East facing
based on our simulation analysis and was also designed to.
So, if you see this is our north , this is our north and we also planned our glazing
elements to to be minimal, in fact . So, I did speak about landscape in the fascade
or in the envelope design which actually has an impact . We also know that studies by the
Lawrence Berkeley laboratory indicates that temperature under trees can be 14 degrees
Celsius cooler than temperatures over tar top roads.
So, actually the original design has a lot of roads around the building this is required
for the fire movement, fire engine.
So, even if you looking at reflective paved roadways also there is going to be a large
impact of heat, heat gain into the building as a result of road area.
So, this is why we had planned a lot of green walls in the facade.
So, the front facade to make it look better has the the green walls in this fashion the
rear facade also has green walls, but creepers will be used . So, we spoke of glass.
So, when we said glass, glass varies from the cost of glass you have glass varying from
75 rupees of square feet to say 275 rupees square feet.
So, which means you it can you know triple the cost of your usage your glass component
if you are looking at the best performing glass.
So, how do we make sure that you know we can keep the cost of glass minimal at same
time have the same impact of you know using a high performance glass.
So, this is where we tried and studied where all should we use the double glazed units
because there are there is a lot of shading elements that you see that shading because
of the building design.
And if you notice this building does not have any external shading devices.
So, there are components of the building which has direct glass and all of those components
will use double glaze unit, but all those which face corridors etcetera will have single
gaze single glass.
And also the window to wall ratio; so, if you see the original design which is this
image , you have three windows on one facade and you have one window where as you can see
the dark pockets in the entire classroom.
So, we do want such dark pockets at the same time we do not want extreme glare coming in
as well.
So, this this light green yellow portion shows uncomfortable light whereas, the dark blue
portions indicate adequate diffused light.
So, what we did?
We converted the doors also.
So, there are doors on either side which were initially constructed to be opaque medium
have been converted to glass.
So, that way we actually achieve adequate diffused light and our window to wall ratio
is designed at 31 percent which was ideal for us to bring in you know adequate daylight
as well into the classrooms . So, I also spoke of choice of materials . So,
this being a precast construction, these are some of the photographs that were taken during
construction.
If you can see you can you see this green portion here that is our insulation . So,
we have used about 40 mm of extruded polystyrene insulation between sandwiched between 2
concrete panels.
Again the insulated panels were not used everywhere there is a combination of panels that were
insulated and a combination of plain concrete panels depending on the direct heat gain analysis
again.
So, only those areas which had to face the direct heat or the direct sun rays had insulated
panels . And if you see the roof this is our section of the wall 60 mm concrete 40 mm insulation
and 150 mm concrete.
Similarly if you look at the roof so, the precast system comes with a system of hollow
core roof slab and , then again all though topping concrete your waterproofing etcetera.
Your insulation was 50 mm.
So, this gives us a desired u value or thermal property of 0.55 watts per square meter kelvin
and for again wall we are looking at 0.61.
So, what did we achieve?
We done this whole exercise and you know double glaze was a single glass daylight analysis
or energy simulation analysis.
If you can actually see the classroom, we change this to glass doors.
So, if you actually see this adequate diffuse light in the classroom.
Look at the temperature difference.
This was recorded on tenth April at 1 pm which is one of which is pretty much your peak summer
time, your outside temperature is 39.6 degrees, your inside temperatures 30.2.
So, what is a differential that we are looking at we have achieved a good differential of
nine degrees or so, 9.4 degrees or so.
So, even in summer you walk into that classroom at 39 degrees outside temperature, you immediately
going to find it more comfortable.
And please note this is just by the use of the envelope , this is just by appropriate
insulation landscape on walls and you know glass, high performance glass all of that
we achieved this . Now in addition so, when we took these temperature readings, we also
did analysis on how do we increase ventilation.
So, this the ventilation mechanism was not in place, this is just an average building
with your walls, roof and your glass taken into account .
So, remember when we did our initial integrated design approach with all our consultants contractors
in place.
We actually wanted to enhance the indoor air temperatures or enhance the performance of
the building in terms of thermal comfort inside the classrooms without air conditioning systems
. So, case one we said you know how do we do, it we increase the openable window
area, we increase DGU area, we add shading devices to our building um.
Second we said let us try in something called the assisted ventilation.
How did we achieve that ? So, every classroom has two shafts . Again
all of this was done with a scientific analysis to support all our calculations.
So, once we come up with a design and and a theory or to prove that we have we we are
doing the right thing, we can always back it with various analysis.
We have today a lot of tools that help us in terms of day lighting. in terms of energy,
in terms of air flow.
So, we did a CFD analysis as well.
So, this has a turbofan on the roof which connects all basically a hollow shaft that
connects across the classrooms vertically and you have turbo fans at the rooftop which
create a negative pressure.
So, you are basically trying to increase your wind velocity . So, this is what I said it
would be a typical floor here classroom.
So, initially we had said we will have shafts in 2 directions, but later on after the
analysis we realized not.
So, much as per the analysis, but in terms of our our precast systems, they said it was
wiser to have diagonals shafts.
So, today we have actually every classroom has two diagonals shafts, this is not there.
And so, this is why we need also every team member to be a part.
So, let us say I have you know, we decided to put in a shaft without the approval or
the knowledge of the precast contractor; we cannot take some decision like this.
So, it was always good to have everybody on the same platform and this is what was a system
design.
So, this was a CFD analysis to determine the size of the shaft . The size of the opening
in each classroom ; so, if you see this is our CFD analysis.
So, when the air leaving the exhaust is at 29 degrees right.
So, we are showing a 2 degree differential with the usage of shafts which will still
so, if I can my 9 degree differential when I operate the shaft can make it 11 degree
differential; I do not need to use AC; 39 degrees outside and if I am able to achieve
a 28 degrees inside my room, I do not need an AC .
So, this is just to show you this is the chart basically our analysis chart.
So, if you see this is a school building right.
So, we take the operating hours from 8 AM to 3 PM and from Jan to December, if you see
the number of operating hours is 176, 160, 184 depending on number of working days Saturdays
Sundays etcetera . Now what is maximum adaptive temperature ? So, in Chennai somebody if I
am sitting in Chennai, I am very comfortable at 30 degrees.
You put me in berlin winter I will freeze, I will freeze at 20 degrees also because I
am used to this.
So, people in Chennai are used to a certain adaptive comfort temperature which is what
we will take into account when we are doing our comfort analysis.
So, we can always say the comfortable temperature is 24 plus or minus 2.
So, 22 to 26 not necessarily may be comfortable for most of us who sit here.
So, if you see the adaptive temperature is around 28, 29, 31sometimes in June, so, this
is again standard analysis.
So, the initial design that we did, we were able to achieve the number of comfortable
hours.
If you see this column this column what we were able to achieve is 194which means only
59percent of the time in January, we were able to achieve comfort conditions during
operating hours.
Similarly if you take in June only 7 percent of the time, we were able to achieve comfort
hours . Now I will add my case number 1 ok I add DGU, I add some shading elements,
I do all of those analysis and I have achieved ; if I do all of that.
My analysis says instead of 59 percent, I increased it to 86 percent .
So; obviously, compared to the first you know 104 hours I increased it to 86 percent
from 59 percent which is still good.
Now what do I do?
If I add my assisted ventilation shafts, then I increased my number of comfortable hours
to 100 percent.
So, from my original design of 59 percent, I have moved to 100 percent in January.
So, I do not need ac in January; similarly in February I have increased it to 80 percent,
I do not need ac again March.
It slowly becoming 54, 51, 21 percent my worst case scenario, but if you actually see I have
increase it from 8 percent to 21 percent.
So, I can use ac, but I will be using it for 80 percent of the time . Approximately I mean
not necessarily I could probably use it throughout the day , but this is what I am trying to
achieve by saying bring the building closest to thermal comfort conditions that you can
. So, without the ac I most of the time; so, 1, 2, 3, 4, 5, 6 months in a year I do not
have to use ac at all maybe the other 6 months I can make it . So, this is how at an average
from 30 percent, I have increased my design my performance of my design to make sure that
60 percent of the time its comfortable which is twice as much
This is just a bar graph to show initial design second and ultimately with your use of assisted
ventilation shafts . So, moving on to the next case where this is the Coal India
Corporate Office Building, the owner being Coal India the architect was famous architect
from Delhi, Raja Rival associates ; built up areas to 2,50,000 square feet.
So, we were basically the green consultants in this project and this was one of our first
few projects I think we started working on this in 2010 or so, and location is Kolkata
again a very hot and humid climatic condition .
So, here we really do not have the flexibility to play around with design because again the
architect has done his own set of analysis.
So, if you see the function and shape is that a pointer here ok, if you see the function
and shape here; there is the floor plate that os designed like this . So, why is a flow
plate the depth of the flow plate this is the open office area again all of this is
the open all of this is the open office area, the depth of the flow plate.
In all these areas is kept to such a to width so, that there is adequate daylight
penetration from both sides and that is why is given us the central courtyards in the
center right and this is the central atrium this is the MDs and the chairmen block; this
side that you see here um.
So, the most critical component where a lot of people would be working and would be sitting
around would be this stretch . Now these two why if you can actually see the building is
in a stepped fashion . Any reason why stepped fashion?
We have a central courtyard here, now if the central courtyard has to be effective we need
to make sure there is enough daylight penetrating even to the ground floors . So, what happens
is a cylindrical form if if let us assume there was no step and this is how the building
was, then you are creating a cylinder over there and this entire portion is going to
be blocking your daylight inside as well.
So, the lower flows will not achieve the adequate daylight.
So, there is a reason why he has done this.
So, this is our energy analysis.
Now initially all of this was glass . There was a lot of glass that was being used in
the initial design . So, much so, moving to window to wall ratio
our window to wall ratio and the initial design if you see this is our initial model was greater
than 60 percent . So, we had discussions with the architect and we come back and say you
know this is what our analysis indicates, we need to do something of course, we do not
want to compromise on the elevation as well because the architect has put in a certain
effort into the design process.
So, what we did is we actually brought in an introduction of wall up to the sill level
. So, wherever when I am saying wall up to sill level, so, this is your slab then this
is again the other flow slab right.
So, here this this whole thing becomes your vision panel.
So, your glass is completely there, but let us say we introduce a wall up to sill level.
So, now, only this portion is your vision panel although you have glass here this will
be glass from the outside view, but will not be vision panel.
So, for us in terms of energy analysis, we will only take into account this portion as
your window to wall ratio . So, after our energy analysis we did read it after the sill
level came up, our window to wall ratio was brought down to 38 percent .
and as I told you we had all the luxury, so, we used DGU use I think they belong to the
(Refer Time: 23:00) series from Saint Gobain which had 0,24 SHGC and a visual light transmittance
of 39 percent and roof over deck insulation was used.
So, they used 75 mm thick extruded polystyrene and for wall there was a lot of wall area.
So, to bring in an insulation would not have been the right thing.
So, what they did instead is going for 200 mm thick aerated aerocon blocks . I think
they were able to achieve a fairly good u value of 0.2 or so, um which is quite an effective
value to achieved.
And also if you see , there is an additional layer of glass.
So, the architect if you see here has used an additional layer of glass again this is
to avoid the harsh glare.
So, that they do not have to actually use your blinds or screens inside the building
so, and at the same time use usage of glass rings and some kind of daylight as well . So,
I was told that they actually do not use blinds in the building .
So, what did we achieve?
We achieved energy savings with solar close to 60 percent and they this this project used
if you actually see the solar I will try show you that
If you see this 140 kilowatts of solar was integrated into the building envelope design
because we did not have enough roof area all of this is solar that has been planned on
the building.
So, 140 kilo watt of solar was also planned.
So, the envelope as such was effectively designed to include all of these parameters
glass your wall, your solar as well . So, we achieved without solar 42 percent, additional
solar was 58 percent and spaces with daylight was again 78 percent and spaces with access
to views were completely 100 percent because most of your regularly occupied areas was
under the open office area.