 I want to ask what kind of materials we can use and on what basis? Sure, Professor Jitain Prajapati will answer that question. Do you see your materials depend on the climate that you are designing your building in? What we found during one of your projects at IIT was the same material may be very good in one climate, but in another climate it may not work as efficiently. Also it depends on the type of building that you are doing. Suppose it is an air conditioned building then insulation or a material having better insulation will work, but the same material if it were used in a non-air conditioned building then it will not work that well. Another building material will work better in that case. So depending on the type of building depending on the type of climate one has to choose their materials. Have you understood? So like for hot and dry climate what kind of materials? Hot and dry climate you will look at materials which are not too thin you know which will transmit the heat very quickly into the room isn't it? So you are looking at at least a brick wall of about 9 inches or concrete of about 6 inches. You have some material in mind which you need to discuss or you need to ask or it is just a general question. Can I add something? So as you saw in Professor Nayak's lecture regarding the time lag aspect so in a hot and dry climate what you would want is that the heat of the afternoon sun is not transmitted inside the spaces in the daytime but because in hot and dry climate it gets colder in the night you would want that heat little bit in the night time. So the material property of time lag will help in doing this where there is a difference in the temperatures of the daytime and the night times. So if you think about a lot of these buildings the historic buildings that are made of sand stone where if you go inside the buildings you feel very cool even in the afternoon times. So those kinds of materials would be helpful in the hot and dry climate. Professor Nayak you want to add something? Hello have you seen the traditional architecture in Rajasthan? They use thick walls stone walls that is precise the reason why they use stone thick walls and my colleagues have answered the logic of using stone thick walls. One more question how to develop microclimate if the space is restricted? There is no general solution it is a case to case basis you have to see what best can be done under a given set of conditions. Microclimate is really you have to understand the context if there are buildings around you then how the wind flow happens if there are trees around you where are the where the shade of those trees fall and based on that you have to sort of locate your windows locate your buildings and how the sun is falling on the site. So it really depends on the context if it is a smaller site which is surrounded by buildings you have to consider the shade and shadow analysis. So in those regards if you go up the context and use some of the energy modeling tools that Professor Prajapati and Nayak talked about that will help you to consider various design options. I just want to add you can modify the microclimate using vegetation appropriately using water around the building appropriately. Hello. 1175 Truba College please go ahead your question. I want to ask that gypsum we are using in the interior walls in Bombay and Delhi. So it is a part of is it a part in green buildings? See you have to understand the again one has to understand the context okay gypsum is easy to use isn't it and that's why people are using it nowadays earlier people used to do what instead of gypsum they used to do plaster isn't it cement motor you know on top of that they would use lime tuna you know niru plastered it was called. So nowadays people are not available who do a good job in that material. So in terms of you know getting good quality people have switched over to gypsum plaster okay in terms of green building we have not analyzed it in that manner yet. Monica do you know whether gypsum plaster is a green material? If there is like recycled content that is used in making the gypsum plaster then it could be considered green but again this is a relative term where you will have to consider what all options are available for those interior walls and then choose the material that has sort of the least embodied energy and the best durability and also the material properties that professor Nayak talked about in terms of the specific heat and insulation properties and things like that. So there are multiple variables that you will have to consider to call that material green. So it's not a straight forward answer professor Anand Achari would like to add something to this. I'll just add to your question regarding gypsum gypsum there are two types of gypsums which is available. There is a natural gypsum which is a stone query from your remote from a stone query and gypsum is also procured from an waste product from an urea chemical fertilizers factory. So today what is gypsum available you need to see where is that gypsum being used in the product. So suppose if you are using in a Rajasthan there would be gypsum which might be procured from a natural query or if it is suppose in South India probably there is no gypsum query which is available it's a phosphate calcium phosphate as a product which is there. So there are many companies which is urea companies which are coming up like in Bombay we have RCF factory rastria chemical fertilizers where the gypsum becomes a byproduct and as a waste product for them. If probably there is companies like which are using this product for developing their ready made blocks or ready made slabs or even for plastering probably yes then you would be as professor Monika Jain said if it has a recycle content. So probably this is 100% post industrial waste rather than becoming a purely natural available material which is a resource intensive. So probably that would answer your question about how gypsum can be diverted towards rather than from using natural to recycle waste. Thank you. Thank you. Thank you sir. One two four one NRI institute. I have a question on using the ash bricks over whole brick is it really advantages to move from whole bricks or chimney bricks to ash brick in terms of reduction of heat absorability of the water and plaster stickiness and does there is there any real cost advantage apart from the environmental advantage. So this is a larger question so I need a detailed answer. I don't think I have the expertise to answer that question. Maybe I can answer it from an architect's perspective. We've looked at fly ash blocks we've looked at bricks also we've worked in those materials bricks are of very poor quality now available at least in Mumbai. They are not dimensional they crumble easily the quality of bricks is really bad in comparison to that we found that fly ash bricks are more dimensionally stable they are of better quality and what happens is that if you have a better quality product they are also bigger in size. So what happened was that we used less labor we required less material to plaster the wall in fly ash bricks they are nice they are factory finished products. So you don't probably require plaster also you can directly paint also after giving a putty outside you need to plaster. So then in that sense it becomes a green product you know you are saving on material you are saving on labor it becomes cost effective and also it gives you a good finish. Your plaster thickness can be of uniform thickness in bricks we found that somewhere the plaster used to go up to one and a half inch thick somewhere it is half an inch thick okay and it's not the problem of the labor or the mason it was the material itself was so bad. In the in Bikan gau where we've used the bricks you know we've used unplastered bricks they are eight inch by four inch by four inch they are also really bad quality but we had to accept what is available and we've used it okay we were we actually wanted to do a red trap bond wall but we were not able to do because of the dimension of the brick but coming back to water of course if you don't plaster your material then you are saving a lot of water isn't it any other question regarding that the heat reduction is there a real heat reduction yes yes I forgot that they are almost the same almost the same so not much differentiates between the two products one question energy you reuse is being adopted extensively in the private sector bigger structures but in the government sector is not being extensively being adopted so if at all it is to be adopted which will save have the national economy which organizations taken care of if I have understood your question you want to say that energy efficiency in buildings not used in general is that the question in the government sector yeah the ministry who are responsible for this are Ministry of new and renewable energy and Ministry of urban development and you can talk to Bureau of energy efficiency and for materials it is BMTPC 1 to 9 6 good morning professor yeah so what is the role of these fins which he has used as a vertical shading devices the role of fins they are used as shading devices that means they cut the sun's solar radiation from a particular direction depending on the wall where is it facing so what you saw was actually the east wall so you know that the sun is at a low angle and you cannot use chadjas there you know horizontal but shading devices are not as effective as vertical shading devices on that particular orientation okay it helps to cut the solar radiation thank you 1178 so I'm also this I finally a student from SNP IT that's umrakh near surat so my question is related to professor Naya's PPD that if we adapt new materials we change our materials on basis of the simulation on basis of the data feeds like specific heat and thermal conductivity can it be proven an economical aspect can it be economical to modify our needs on basis of simulations there are softwares who provide you also building cost etc so one has to incorporate cost calculation along with the thermal calculations then you will get it okay and sir we have seen an example of cities like the Mazdar built in Abu Dhabi the whole city is planned with perspective of green architecture and sustainability issues so is can any such initiative to be possible in Indian scenario why don't you take the lead it can be in principle it can be done in principle it can be done somebody has to take the initiative to do that we have we have thank you very much yeah 1 3 0 2 I have seen up from Shri Vidya College of Engineering good morning is there any importance for the plan or shape of a building to be considered after green building plan or shape of the building yes you can there is a lot of importance in fact in that school which you saw we all the longer sides of the building they face towards north and south okay the main walls were facing towards north and south why because it is easier to shade those walls rather than the east and west so you need smaller chajas the projections that come out from the from the wall need to be smaller so the control is better thank you 1 1 9 2 so is concrete is a green material all materials are green all it's only it's only the you know when you compare it to another material you might get a better material so basically if you consider even buildings now all buildings are sustainable but only some perform better than others okay so it's all a relative question by itself concrete is a green material okay but if you compare it to say fly ash concrete block then fly ash is better because it uses recycled content it is lighter also so transportation is easy hello sir I have one more question as we know that US United States have seven times more in your energy consumption than ours to maintain their good quality of life so how is it possible or how it is easy for us to have a sustainable energy use planning for a building where in a country like India the basic need of shelter is difficult to fulfill okay you saw the school building that we did in Bikanjau so what you can do is you can like professor naiak said you can harness the forces of nature so that you don't require or you require minimum auxiliary energy okay in that school we do not use any fans and tube lights in the classrooms okay the comfort is mainly by ventilation and it's because of the passive solar design okay so it is on us as designers to design a building which will not require energy isn't it or even resources we can manage our resources better so what we did was because the requirement of energy was so less then we could afford to go in for photovoltaic solar for the offices part of it let me just add a little more to it if you remember the human development index chart US was way above in terms of energy consumption but if you look at Hong Kong which has a similar quality of life as the US but it has much lesser energy consumption per capita so there is a possibility of attaining a good quality of life by having lower consumption the point is to have comfortable living by providing temperature and environmental variables that are comfortable for human being by adopting passive means and reducing the artificial energy that we use 1 double to 8 good morning this is Remy from like Genaic yeah my question is whether can we regulate the internal side of green building so that we can get the same comfort that is available in a normal air-conditioned room do you mean that can passive solar be as comfortable as air-conditioned room is it is that your question no it can never be because here you are maintaining in air-conditioned buildings you are maintaining at a constant temperature within a very narrow range isn't it in passive it depends on the external climatic conditions so the range varies and people have to start adapting also their lifestyle to the climate and the design okay so people become more active in passive design buildings I want to add one thing here you know you have artificial source of energy you are controlling the control is much efficient in air-conditioned building but that doesn't mean that passive buildings are totally uncontrolled a fair degree of control can be made by appropriately designing the building so should not have the impression that passive buildings are totally uncontrolled but yes the degree of control that one gets in an air-conditioned building will not be available in a passive building one has to find out whether that control is required at all for a given requirement if it is required then you have to probably go to air-conditioned building and just adding one more thing that there are technologies available that can actually be a combination of passive architecture and incorporate some some controls so like the heat recovery system and things like that so there are technologies available that can be a combination of both I got another question and does the location is a real that the location of the building is a real factor in rebuilding the quality I think we have already answered that question so can we move on to the next center it's the context specific architecture we've talked about I think multiple times good morning ma'am I want to ask that while doing the thermal analysis in desert areas how will you consider the climate change because it is dry in hot like it is hot in days and cold in nights so how will you do exactly what type of materials you use send your questions on chat also and I think this question has been answered partially initially but professor Nyak will take it up the climate save such a huge variation in divernal temperature what you said daytime's are pretty hot nights are pretty cool so one has to add use this benefit I mean use this facility for the benefit of the building that means during nighttime allow the ambient air to come in store that coolness in your building hazards use that coolness for that I am comfortable so there are designs which are possible create induced ventilation in the night use materials which have low emissivity so that store the coolness in the building I would advise you to look at some references which my colleague jitain sold in his presentation you will find answers to your question one two five six good morning how can the way water recycling can be done if a building is constructed in the middle of the city see even in the city you have some trees and plantations so you can use the grey water for irrigation okay after a little bit of filtration and you could also use the grey water by a little bit of a filtration in the flushing systems in the toilets so there are ways where you can and as I yeah and as I showed you that you can plant on your rooftops in urban scenario or you can have plants and vegetables in your yard so you can use that water for irrigation purposes in the buildings as well in city areas also 123 I have a doubt on that psychometric concept of what do we consider in that psychometric point of the green building design psychometric analysis it's a tool and what it is it is a software you can download it and check it up okay it does the analysis of the climate and it will also give you certain guidelines okay how to achieve more comfort okay using the psychometric chart we don't prepare it it's an inbuilt thing in the tool okay so please download that software climate consultant there was a point called micro's climatic and psychometric analysis so what would be the output of the psychometric analysis where it deals with you get certain guidelines to do passive solar architecture okay it helps you to define those what can you do now do you require evaporative cooling do you require shading do you require ventilation so it will list down the efficacy of each technique that can be applied psychometric and microclimate they are different altogether psychometric chart is a chart of a chart showing air properties so you will have plot of temperature humidity ratio relative humidity etc in that chart you superimpose your comfort requirements you will get a set of design guidelines as opposed to that microclimatic analysis is different around your building what is that you can create an environment that benefits you by setting by admitting daylight or not admitting daylight these are or creating a water pond so that your humidity increases temperature decreases so these are microclimate related studies thank you very much sir my question to you is you have talked much about the new buildings but what are the design considerations or else what are the considerations that are that will be given to the existing buildings sir because ours is a 30 years old organization so how can we convert our building into a green building okay you need to do the analysis first and then you will get the answers for that okay so you use the same approach that we had used and you'll still get the same results okay so it's called retrofitting a building okay but the process is the same you first have to analyze the climate you have to analyze the building requirements you have to analyze the function and the building envelope and then you will get certain feedback from your analysis on what to do what is the status of recycling of materials in building and road sectors with reference to research and development and actual usage at site see this question would be better put to you an organization like CBRI Central Building Research Institute or BMTPC building materials technology prouncil okay they do a lot of research and then maybe you'll get better answers to this questions thank you 1 to 6 0 I am professor Eswant Pawar from senior engineering college Punderpur my question is what is life of green building as compared to so-called non-green building located at same climatic condition it is the same durability is the first issue you look at in any building that to so-called non-green building located at same climatic condition the life is the same you cannot say that you can design a green building and say that its life is going to be less than a conventional building that is not how it is to be approached see because durability safety all those concerns are also an issue in architectural design so you must look at those also hello you have shown one picture where plastering is not done yeah okay but due to weathering effect is it not possible that there there will be disintegration of that external exposure surface yes but we have shaded the walls also and this is not in a place like Mumbai where there is lot of rainfall but in a dry climate so you need to you know you have to be aware where you are doing your work and what type of materials you are using now the same type of unplastered wall if you were to use in Kerala then you are you aware of Laurie Baker's buildings so he will have a huge veranda in front of that wall so that it never gets wet okay so you have to save your wall one two five seven hello good morning sir Dr. JK Nayak has told that we have some commercial software available for the simulation purpose sir I want to know about the open source of softwares available for the simulation purpose of thermal performance of the buildings yeah there are many open source so I will ask my colleague to give you a list of open source softwares open source means you want to change the source code or you just want free software only free software basically you want to use a free software yes then equest is very good and it uses DOE as the simulation engine there is energy plus also which is more advanced than supposed to be more advanced than equest you can download both of this from the internet they are freely available there is ESPR from Europe that is also very very good software all this software have been validated okay and you can use them that means they are the technology has been actually tested radiance for daylighting ma'am as you have said that under the green building evolution systems even a platinum certified building may have carbon emissions for transport that is in that site are you sure that they have not taken into account the any credit for the fossil fuels because under the site efficiency they have a credit for non fossil fueling facility for the vehicles so this was just taken as an example to illustrate the point that when you are thinking about green buildings it should be considered in the context in the larger context so if you are locating your building where there is no public transportation and everyone is using petrol driven cars then that reduces the effect of the greenness of that entire environment so definitely there is the site selection is one of the criteria in these evaluation systems so you have to go by all of these different criteria my question is that so do you mean that the platinum certified building is still not an ideal green building I don't want to point out specifically like that but I this was a thought provoking comment where I would like all of you guys to consider that just not going by the evaluation systems but considering the larger context a platinum there can be a platinum certified building in say Mumbai or New York where the building is accessible by public transportation whereas it could be in Los Angeles kind of situation where you are driving your car so those two although they are the same platinum certified buildings but they will have much different impact on the greenhouse gas emissions and the environmental system okay thank you ma'am okay yeah I have exhausted our 45 minutes so we'll take more questions in the next interactive sessions and we'll continue with the lectures now