. Welcome all to the session of Energy Efficient
Facade System. I am Varghese I am heading the facade division of Sobha. Today we will
discuss about the balanced facade. Where as you know facade is like the skin of the body.
It is a very vital organ of the body it will give shape to the body it will control the
body like that facade is always very important element of the building. When we talk about
any facade it should have six to seven. Aspects one is aesthetics, another one is
structural integrity it should be durable and the facade should be cost effective and
it should have the energy efficiency also it should be easy to maintain and functional
flexibility is also important. If you look at it many of the things are contradictory.
When we work for something the other aspect will we have to compromise on this. Today
we will discuss about a system where the energy efficiency is given the prime importance.
We will try to achieve all other aspects in optimum benefit, but giving more and more
importance to the energy efficiency from this the aspect of energy efficiency will be discussed
in detail in this session we can call such a facade as balanced facade.
If you see recent times in the facade industry a trend is there to save lot and lot energy
energy not spent is energy saved. So, usually we will be um having we have to approach this
in two aspect one is to spend less energy on air conditioning or inside the building,
second to cut down the energy what we are spending for artificial daylighting. So, this
aspects will be discussed in detail. We if we discuss about balanced facade at least
four things we have to consider. One is the sufficient day light should be
there in the building without much artificial lighting second is energy efficiency of the
building where all heat ingress of the building we have to reduce, third is to avoid glare
and radiation. So, that the occupant will have maximum comfort level other challenge
is to bring day light to deeper or inner core of the building. Here I am showing a typical
section where this aspects of energy efficiency is kept in mind while designing the particular
section. Suppose a building of 4 meter 4.2 meter floor
to floor one method is to give the entire floor having facade glasses, but here in
this particular section what we have what we are doing is to give around 50 to 60 percent
of the glass other area we are leaving as it is for other architectural elements. In
this case we have a facade of around 2.4 meter having few elements designed for specific
purposes to arrive this design criteria we have to consider seven steps or we have seven
different steps to arrive this particular section.
The first step is sun path analysis now a days if any major building facade design
starts with study of the area and study of the sun path analysis as per the building
orientation. Suppose the building orientation is fixed then according to that orientation
a sun path analysis will be done considering the.
The whole year this this is a simulation of sun path for the entire year for the the all
four seasons and even hour to hour. So, this will give a clarity where what are the sun
penetration from the various various parts of the building and elements can be designed
accordingly the ultimate aim is to have the energy efficiency in our mind and to have
a complete comfort level to the occupant those who were sitting on the periphery of the building
also. The next step is to propose the facade ideally
around 50 to 60 percent of the floor height. We can cover the complete floor height also.
So, the balanced portion that 40 or 35 percent of the portion will be treating ss spandrel
panel where glass will be there from the outside, but there will be insulation inside.
So, that that particular area is designed for maximum insulation. So, the facading question
will be around 60 percent of the floor to floor Where this particular section of the
facade will be splitted into five definite elements. One is the total height of that
60 percent height suppose it is 2.4 meter around two third of that height will be designed
as a vision panel. If you go back to the section this around 2.4 meter facade where the lower
portion designed as a vision panel it is almost two third of the high and the upper portion.
One third is designed as a day light panel where the function will be discussed little
later and these are two major elements and there is an element called external chajjah.
Where as per the sun path analysis a certain width of this chajjah will be designed. The
primary purpose of this to have to cut down the sun radiations and it will help up to
certain extend in the heavy rainy season also.
And another element you can see inside where we call it as a light shelf where it also
having purpose of cutting down the sun radiations and also to having the function of giving
light to the internal portion of the building. So, after doing the sun path analysis
a section is proposed. Total height two third is given for vision
panel one third is given for the day light panel. A sufficient width chajjah is proposed
and a sufficiently designed internal light shelf is also designed having the purpose
of cutting down the radiation and giving the light to the inner portion of the building.
Now one more area is suppose during the lateral movement of the sun we will have
radiation even after providing sufficient width external chajjah. Here we are addressing
that issue by providing vertical fins in front of our mullions.
Here frosted glass or any other solid thin elements will be placed vertically in front
of the mullion. So, that radiation due to the lateral movement of the sun also will
be arrested. We will come come back to this particular section where we have all
the elements in place. The design involves two as per the datas obtained
by the sun path analysis we have to select the glass for the vision panel glass for the
day light panel sufficient width design for the external shading element. And there
is an width criterion for internal light shelf and to provide the
Glass fin or the fin externally vertically to cut down the radiation due to lateral movement
this particular section shows a typical section where all these elements except glass fin
is provided. If you go back to the go to the section we have various options for
this this is particular glass in what we have shown for all this elements we have various
various elements to select from. And most important as you know is the glass
selection where have seen many sessions here to educate the students about the criteria
of glass selection here . We have a very important role of selecting
the vision glass where the purpose is to give sufficient light, but to make maximum insulation.
Where I suggest a double low E glass of U value around 1 how we will achieve the U value
1. You you are aware all aware that the glass single glass providing with this double low
E coating may not fetch the required result. What we to provide here is an insulating glass
of sufficient thickness may be 27 32 mm thickness having inert gas filling in it and carefully
selecting the light transmission percentage we can achieve a U value of 1. Here I suggest
for the this thing vision glass of U value 1 and having around light transmission of
40 to 50 percent. This 40 to 50 percent light transmission will
be sufficient to give a optimum lux level for the building peripheries. We may have
around 300 to 400 flux level which is more than sufficient to work with.
So, when you the most important of this selection of these elements the prime is selection
of vision vision glass because it is covering the maximum area of the . So, go for a double
low E having around light transmission 40 to 50 percent after treating with insulation
techniques we will get a U value of 1. Here I am not taking any brand for the glass
that selection is to the clients or to you to decide, but we have a range available
in the market where LT is mentioned and U value is also mentioned after sufficient treatment.
When coming to the upper glass day light glass again we have to go by a low E double low
E or tripe low E even here the purpose is little different.
We need to get sufficient light at the same time we have to cut down the the radiation
part of it here this one third of this glass this particular section selection will be
little more open glasses where light transmission will be around 60 to 70 percent we can have
triple low E here sufficiently treating the glass with insulation techniques we can
achieve a U value of around 1.2. So, after doing this both glasses selecting
both the glasses we can go back to the sun path analysis. And we can decide the width
of the external chajjah it is very very important. The idea is to cut down the radiation to 0
up to 0 level where all the occupants of the building either those who are sitting in the
periphery or inner part of the building will have a complete comfort level from the
radiation. Here start with a 2 feet or 3 feet may
be in certain cases it may go to 4 feet also, but for this particular external
light shelf for external shading element we have lot of options what we are discussing
in in the coming in the next pages. Coming back to the other elements other
than this three we have internal light shelf where is a horizontal element providing
with sufficient width this also width we have to simulate it from the sun path analysis.
We have um from 2 feet to 20 half feet horizontal element lightweight and little
thinner element. So, that it will look nice from the it has to go well with the internal
portion of the building. What we need is a maybe an MDF with treated top and bottom
differently. Why I am telling top and bottom differently
here the light shelf top should be totally glossy. We need to have a glossy laminate
on top. So, that when we have radiations coming from outside it will be hitting on top of
this and it should go back to the ceiling of the inner portion which will again reflect
back to the inner core of the building. So, bringing the sufficient day light to the inner
core of the building this particular selection of internal light shelf play a very big role
usually we will go with very high laminate on top white colour. So, that whatever
light coming on it it will reflect totally to the ceiling of the building which in
turn ceiling will reflect back to the inner core of the building. We will coming back
to the selection of external light shelf. You can have many options are available
we have to balance this functional aspect with the aesthetics also we can [hove/have]-
have aluminium composite panel sufficient width. We can have even light laminated glass
chajjahs where frosted chajjahs can be used for the purpose which will add aesthetics
also. We have even multiwood options are available
we have most of the time we will use louvered chajjahs where the advantage is it will bring
down diffuse light to the bottom. So, the front facade of the building still will be
lid with sufficient day lighting and at the same time it will cut down all kind of radiation
we have to adjust the blades of the louvers where it will cut down the sun radiations,
but at the same time it will bring diffuse light to the building.
So, this is a this by selecting the correct material for the chajjah adjusting the
correct angle for this louvers we can have external chajjah gaving the function of cutting
down entire radiations at the same time it will give diffuse light to the periphery of
the building. So, this in this particular manner what we are planning what we are
achieving is the keeping the artificial lighting at the daytime a minimum we have
to try for the 0 day lighting and we will end up using very very minimum day lighting
for the purpose. And all kind of heat ingress to the building we have to keep minimum.
Here I told you we have we have a statute restriction of using glasses after treating
to have a u value of 2.5, but here by carefully selecting and treating repeated insulating
process. What we try to achieve is to have a glass of treated glass of value U value
1 that is very good for the building facade where energy ingress will be very very less.
And bringing the light inside the building cutting down the heat ingress up to the maximum
the facade slowly become a balanced facade. Where all the other aspects is dealt
with with optimum results. Coming back to the sections where the few
facades we will show here. Where with this is a facade having all this kind of elements
appeared here where coloured glass fins are used to have the optimum results for lateral
movement you can see here solid chajjahs used with aluminium composite panel where
many areas for aesthetic purpose we have used aerofoil louver where angle and all adjusted
to have the best results and This here we can see lot of external shading
elements are used chajjahs are used the here we used solid aluminium composite panel
where the area having very bright sunny sun of the part of the countries we can
use the solid aluminium chajjahs here we used box sections in a loured manner to add aesthetic
at the same time it will cut down the radiations up to certain extent. And through that vertical
light will be given. So, that the facade externally facade will be properly lit.
We have aerofoil louver again we have option of partly frosted glass and partly aerofoil
louver. Internal light shelf of the all discussed usually will go with a MDF having top treated
with highly gloss laminate bottom. We can have any laminate having of which will
go with the internal interior of the building this is a typical balanced section. Where
internal light shelf is given of around 2 feet we have around 2.3 2.4 meter facade
having day light pane we have a vision vision glass day light glass we have openable
panel usually openable panel will be given in the vision areas where we kept a ratio
of two third and one third. This particular fin elements we have to discuss
usually we have all the options we have frosted glass is the first option because
it will go very well with the aesthetics easy to clean and when we frost it it will cut
down the sun radiation up to certain extent or up to the maximum and still it will give
a little glow or diffuse light to the facade. We have solid fins we can give even ACP fins
are possible, but it will look bulky glass fins always will be thinner and neat. This
again external view of a balanced facade having see the shape of the glass fin. Where it is
separate these are all datas simulating from sun path analysis.
And the external shading element considered design as a combined unit where first 2
feet portion is designed as a solid later we have aerofoil louver to this is to bring
aesthetics to the building also. If you see the total height of the floor it is around
4.2 metre out of that 2.4 meter is taken for the balance of the facade element other area
is treated with sufficient insulation. So, that total heat ingress to the building
kept minimum. These are all various options for glass
fins again now a days lot of colours coming into play. We have safety treated glass
fins can be used for this purpose usually ceramic fritted glass will be used. Here
we have to add the safety or also always this such a glasses will be used with lamination
of sufficient thickness. After discussing the balanced facade we have further
methods to enhance the energy efficiency. We can bring down heat ingress to the building
further by using this particular technique thermally broken system
This thermal break usually will be used in to cut down the heat ingress through the
aluminium you know any facade having metal light weight metal like aluminium and major
area will be covered with the glass. we have all the techniques of treating the glass
to bring down the heat ingress where we have double glazing techniques using this
spaced with inert gas. We have lamination techniques all bring down the U value of
the glass area where the heat conduction through the metal aluminium is taken care
by using a technique called thermally broken system.
Here the aluminium sections . Aluminium sections will be designed and which will be broken
into two isolated from inside and outside. If you the a the section. Where we have the
glass outside where inside is the aluminium section were the structural part of it is
split into two or split into many compartments where the direct chance of direct heat ingress
is reduced we you use an insulation material called isomat.
By this we can cut down the heat ingress through the aluminium metal Any facade will have
10 to 15 percent of the metal and balance 80 to 85 to 90 percent glass area where
this 15 percent of the area is further strengthened by using this technique.
This is what we discussed about balanced facade today I will summarize we have
a facade having many functional aspect out of that one particular aspect is considered
for energy efficiency today where seven steps are there starting with sun path analysis
we have to carefully select the systems sections height of the facade a balanced facade
then later all the elements of day light vision glass external shading element internal shading
element glass fins are designed all the width and selections are all depending on the requirement
of your energy efficiency and sun path or sun path analysis of the area.
And we have to provide the sections with sufficient glass fins on front to cut down
the radiations. Here energy ingress is also controlled and we are bringing sufficient
day light to the building. So, when we achieve all this from a normal facade this particular
facade is called a balanced facade. Thank you.