Research Paper on A Comparative Analysis of Carbon Reducing Bio-Facades

A COMPARATIVE ANALYSIS OF CARBON-REDUCING BIOFACADES Role of Architectural Research Paradigms [ARCH 509]

BACHELOR OF ARCHITECTURE Amity School of Architecture and Planning, Noida Amity University, Uttar Pradesh

Harshita Choudhary A1904020025

Under the guidance of Ar. Bhuvan Kumar Mitra

Declaration I hereby declare that the project entitled “A Comparative analysis of carbon reducing bio-façades” submitted to the Amity School of Architecture and Planning (ASAP) is a record of an original work done by me under the guidance of Ar. Bhuvan Kumar Mitra, Faculty Guide, ASAP from __/07/23 to __/10/23.

Harshita Choudhary A1904020025

Acknowledgment I would like to express my heartfelt gratitude to Ar. Bhuvan Kumar Mitra, my esteemed professor and mentor, for his invaluable guidance and unwavering support throughout the journey of this research. Mr. Mitra's profound knowledge, dedication, and patience have been instrumental in shaping the direction of this study.

I also extend my thanks to Amity University, Noida, for providing a conducive academic environment and resources that facilitated the completion of this research project. The university's commitment to excellence in education has been a prime mover in my academic pursuits.

Furthermore, I would like to acknowledge the contributions of my peers and fellow researchers who provided insightful discussions and feedback that greatly enhanced the quality of this research.

Last but not least, I convey my gratitude to my family and friends for their encouragement and support, which has been a abiding source of motivation throughout this academic endeavour.

This research would not have been possible without the collective support and encouragement of these individuals and institutions. Thank you for being an integral part of this academic journey.

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Abstract The current global average concentration of CO2 in the atmosphere is 418.96 ppm annually as of June 15th, 2023 (Data source: National Oceanic and Atmospheric Administration (NOAA). This is not only an increase above 300ppm since the Industrial era but is now well over 400ppm, which has happened for the first time in over 800,000 years.

If emissions are produced with the current climate policies intact it will lead to a 2.5-2.9 °C increase by 2100. This could lead to conditions no to be seen on Earth for another million of years.

Architecture and the building construction sector also have a huge role to play in this catastrophic change thus we should find ways to not only control but also reduce carbon dioxide emissions. This research paper, therefore, offers a comparative analysis among a few selective carbon dioxide reducing bio-facades, in an attempt to understand which of these is best suitable and how we can use green or man-made materials to reduce carbon in our environment.

Keywords: Bio- façades, Carbon dioxide reduction, Green wall, Water based façade, Microalgae, Bio-char based façade

Aim The aim of this research paper is to understand the various types of Bio-Facades that absorb carbon dioxide from the atmosphere and to create a comparative analysis of each. To understand the application and utilization capacity of each façade in the research. To compare and analyse based on decide factors which façade works best within the Indian region, and how much can the studied facades actually play a role in reducing the carbon footprint of a place.

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Scope and Limitations • This research is confined to data analysis and comparison of various carbon-absorbing bio facades.

• Due to the inability to test materials in a lab the research will be based on data collection and testing done by various other researchers.

• The comparison based on selected factors shall provide an insight into understanding which façade is the most suitable with most climatic and regional locations

Objectives • To understand various individual Bio-façades that absorb carbon dioxide • To understand the comparison between selected bio facades and contemporary facades • Based on selected factors create a comparative analysis between chosen bio facades • To conclude the research paper with an understanding of the scope of improvement and impact that the selected bio façades have on the environment

Methodology • To study the research papers based on bio façades extensively and select the ones for this research paper based on the criteria set • To study and analyse the factors based on which a comparison can be created first between the bio façades and the contemporary façades, and secondly between the bio façades selected.

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INDEX Sr. No.

Name

Page No.

1.

Introduction

5

2.

Theoretical Study

6

3.

WaterBased Bio Facades

7

4.

Green Facades

8

5.

Microalgae Based Facades

10

6.

Biochar Based Facades

11

7.

Comparison of the Selected BioFacades

12

8.

Conclusion

14

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1. Introduction In the face of a rapidly changing climate and the pressing need to reduce greenhouse gas emissions, urban environments have become a focal point for innovative solutions that mitigate their contribution to global warming. Urban areas, which house more than half of the world's population, are responsible for a significant share of carbon dioxide (CO2) emissions, primarily due to energy consumption in buildings and transportation. Consequently, the urgency to adopt sustainable and ecologically sound practices within cities has never been greater(Pearson & Palmer, 2000).

One promising innovation at the intersection of architecture, biology, and environmental science is the concept of "biofaçades." Bio-façades are vertical building surfaces adorned with a variety of living vegetation, such as mosses, algae, and vines, and integrated with advanced eco-technologies to actively reduce CO2 levels and enhance the urban environment. This approach leverages the power of nature to not only improve air quality and reduce heat island effects but also to sequester CO2 directly from the atmosphere.

As the world grapples with the consequences of climate change, the potential of bio-façades to act as carbon sinks while enhancing urban aesthetics and liveability is a subject of significant interest.

This research paper delves into the multifaceted aspects of biofaçades as a sustainable, innovative solution for carbon dioxide reduction in urban environments. It explores the mechanisms and biological processes behind bio-façades, the integration of emerging technologies, and the broader implications for urban sustainability and resilience.

By analyzing the latest scientific literature, case studies, and real-world examples, this research paper seeks to answer key questions, such as the efficacy of bio-façades in carbon dioxide capture, their economic and environmental benefits, and the challenges associated with their widespread implementation. Furthermore, it aims to provide valuable insights and recommendations for urban planners, architects, [5]

and policymakers seeking to incorporate bio-façades into the built environment, thereby contributing to a greener, healthier, and more sustainable urban future in India.

In a world where urbanization is on the rise, the reduction of carbon dioxide by bio-façades represents a tangible and innovative step towards enhancing the environmental resilience of our cities, addressing climate change, and improving the overall quality of urban life. This research paper is a call to action, inviting all stakeholders to explore the possibilities that bio-façades offer in the quest for a sustainable and thriving urban future.

2. Theoretical study Energy from the sun is absorbed by the Earth’s surface, oceans, and atmosphere and is subsequently released in the form of infrared thermal radiation into space. Greenhouse gases play a huge role by absorbing this infrared radiation and helping to maintain a stable climate. Carbon dioxide, one of these greenhouse gases, remained at relatively stable levels of around 280 parts per million (ppm) for centuries. However, since the onset of industrialization, carbon dioxide levels have steadily risen. Over the course of the past century, there has been an annual increase of approximately 0.28 ppm in atmospheric carbon dioxide concentrations. Around the 1970s, carbon dioxide emissions had reached a point where the Earth’s capacity to naturally process them was exceeded. As a result, carbon dioxide began to accumulate in the atmosphere at an accelerated rate, eventually surpassing 400 ppm.

(Hashimoto, 2019) Through various research papers it is understood that the building sector has a critical role in the emission of carbon dioxide into the atmosphere.

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(Source: NOAA)

Thus, this research paper delves into one of the many methods through which we as architects can not only contribute in reducing emissions in future projects but also in absorbing carbon dioxide currently in the atmosphere through the use of carbon dioxide absorbing bio facades. The facades that are discussed in this research paper are as follows: • Water based Bio-façades • Green façades • Microalgae façades • Biochar based façades The comparative analysis of each selected bio-façade is discussed post the theoretical understanding of each type of façade.

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2.1 Water Based Bio-Facades These Bio-Facades are an innovative architectural and environmental solution designed to mitigate carbon dioxide (CO2) emissions, improve air quality, and enhance the aesthetic appeal of a building. Water is used as an absorbent for pollutants in the air, based on the purification method of rain. The fine dust particles get absorbed within the water droplets of the rain and solid particles will fall as raindrops.

Another method of understanding how water-based BioFacades function is understanding the mechanism of the widely used Anti-smog gun machines on construction sites across New Delhi. The Anti-smog guns emit a fine, atomised mist of water using high-pressure propellers, producing a rainlike effect. This causes an augmentation in the concentration of airborne particles, compelling them to descend and settle (Department of Environment, Govt. of NCT of Delhi).

The water-based bio façade methodology is utilised beautifully in the Manitoba Hydro building, which has an affordable structure with efficiency and relies on passive free energy without compromising the design quality and, most importantly, human comfort (Bastanfard, 2018). This building is distinct from the typical North American office buildings that rely solely on recirculated air, as they maintain a constant supply of 100% fresh air throughout the day and all year round, regardless of external temperatures. The building’s core features are its three six-story south-facing atria, which serve as the building’s respiratory system. The atria bring in outdoor air and prepare it before distributing it into the work areas through adjustable floor vents. Based on the season, a 24-meter-high waterfall in each atrium either adds or removes humidity from the incoming air. In colder weather, recovering heat from the exhaust air and passive solar radiant energy are harnessed to warm the fresh air. The treated air is then directed through the raised floors and delivered into the office spaces via underfloor fan units. The water temperature can be adjusted based on the relative humidity of inner spaces via the [8]

thermal converter by the building's management system. By using a pump with a sensitivity towards pollutants, the water operates by a process of reverse filtering to eliminate unwanted particles from the air.

(Source: Manitoba Hydro building)

(Source: Cooling strategies comparison, Ivy Panda)

2.2 Green Façade Plants on either a small or large scale have a significant impact on the mitigation of air pollution (Sheweka & Mohamed, 2012).

Because of the lack of available space in cities, the adequate planting of trees and shrubs is often not a viable option, for this reason, green or vegetated facades are one of the most popular and common ways to absorb air pollution in cities.

They are flexible in nature and can be added to both old existing or newly built structures. These facades are capable of filtering toxic gases, suspended particles, and any other contaminants in the air (Rezazadeh et al., 2022).

The leaf surface absorbs the dust and filters the toxic gases.

The filtration is carried out by plants and through microorganisms (Green Roofs, 2008). Although this research paper explores the carbon absorption tendencies of a green façade, there are many more advantages of a green façade, such as improved thermal performance of a building, reduction of greenhouse gases, heat island effect, and noise pollution. Green facades can be categorized into three broad [9]

categories and are sub-divided into two further parts, as mentioned below: Vertical green system Living wall

In-place living walls

Prefabricate d living walls

Green facade

Plant coverage Prefabricate d panels with plant coverage

Plant coverag e with natural growth

Root in the soil vase or box

Root in soil

Living walls Premade living walls: They are a system of premade panels or integrated fabric that are affixed to a frame or a structural wall.

The resulting walls created by this system have the capacity to accommodate a diverse range of plant species. Containers and geotextile bags are employed in this method, with these containers being affixed to a backing and, on occasion, connected to the wall structure.

In-place living walls: These are semi-prepared systems and are attached to the façade. The plants are placed in a box with a layer of wool installed below them. The plants have a limited capacity to grow due to the determined capacity of the boxes (Patarlageanu et al., 2020).

(Source: Living wall system Canada, Verticaloxygen)

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(Source: ANS Global)

Plant coverage of the wall Green cover on pre-made panels: The panels are made of concrete and have pores between the pebbles. These pores are filled with soil and provide the space for growth. There are only a select few species of plants that grow in these types of panels.

Natural green cover: These are usually seen growing on top of historical buildings and grow without the need for human intervention.

(Source: Florafelt living wall systems)

(Source: MicroVeggy)

Green façade Root in soil: There is no need for a supportive structure in these types of walls. It takes a long time for the plan to cover the whole surface of the wall.

Root in the vase/box: These types of walls need vases for plants to grow in. There is an irrigation system that is required because the roots of the plants are not directly in contact with the ground soil (Bastanfard, 2018).

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(Source: Green Façades, Urban green-blue grids)

(Source: Quatro design)

2.3 Microalgae Façade Algae are the simplest forms of plants i.e., they are without roots, stems, leaves, and other plant organs. These are singlecelled organisms. These plant species have a very high ability to absorb and reduce carbon dioxide because of their high surface-to-volume ratio. They play a crucial role in generating approximately 60 to 75 percent of the oxygen required by humans and animals. They can achieve this by absorbing carbon dioxide from the atmosphere or water during photosynthesis, surpassing the oxygen production of all forests and plant life on Earth. In addition to their carbon dioxide absorption and oxygen release, microalgae generate a type of green biomass and nutrient-rich protein. Furthermore, microalgae exhibit remarkable photosynthetic efficiency, being approximately 10 times more photosynthetically productive than mature trees and shrubs. To yield 1 kilogram of microalgal biomass, they need to absorb 1.8 kilograms of carbon dioxide (Hanafi, 2021). These organisms thrive in all sorts of aquatic habitats, although the best sort of environment for their growth is sewage water due to the ample nutrients it provides. Given that building walls offer a substantial surface [12]

area exposed to polluted air, incorporating microalgae into building facades in the form of biological facades can effectively transform these walls into photosynthetic surfaces.

This innovative approach serves to enhance the building’s passive thermal performance, effectively addressing the challenges posed by climate change, and elevating an ordinary structure into a healthier and more vibrant living space.

Furthermore, it can essentially convert the building’s walls into a functional power source (SAMEH KAMAL ELDIN & HEDEK IBRAHIM, 2021). Implementing this microalgae integration with the building façade necessitates the inclusion of a water storage system for cultivation. Therefore, it is imperative to assess the feasibility of incorporating suitable microalgae species into the cultivation system and evaluate their capacity to adhere to the building façade (El-Mahdy & Youssef, 2022).

BIQ apartment in Hamburg is the first built model in the world to utilise the idea of a Microalgae façade as a purifier. These algae façades protect the building from excessive sunlight and reduce heat gain within the building. The bioreactor takes this energy and converts it into usable biomass (FytrouMoschopoulou, 2013).

(Source: The Water Network)

(Source: Bouygues Construction)

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(Source: ResearchGate)

2.4 Bio-charcoal based Façade These types of facades are an emerging architectural and environmental concept that leverages the unique properties of biochar to create sustainable building exteriors. Biochar is a charcoal-like material that is almost pure carbon and is made by burning biomass like secondary agricultural and forestry offcuts in a low-oxygen environment through a process called pyrolysis. This material is approximately 90% carbon and stores around two tonnes of carbon dioxide (Hahn, 2021).

Biochar is integrated into the façade construction as a component of the building envelope. It can be used in various forms, such as biochar-infused concrete, panels, or tiles. These biochar-based materials can be used as cladding or siding for the building. This type of façade has a high surface area, which allows it to effectively capture and store carbon. When used as a part of a façade, it can absorb carbon dioxide from the surrounding air, similar to how trees and plants perform photosynthesis. This carbon absorption helps reduce the carbon footprint of the building and contributes to mitigating climate change. Their thermal mass properties provide [14]

insulation to a building which further enhances the energy efficiency of a building, reducing the carbon footprint of a structure further. Since biochar is combined with a sugar cane binder to create thermoplastic granules that can be melted and moulded they are versatile in nature and can thus provide visually aesthetic creative options for architects and designers alike (Hahn, 2021). They are also very low maintenance in regards to cleaning and periodic inspection to ensure continued effectiveness.

(Source: Laufs Engineering Design) (Source: Material Lab)

(Source: Dezeen)

3. Comparison of The Selected Bio-Façades In this research paper, four types of carbon-absorbing biofaçades were introduced, and the characteristics of each biofaçade were described in detail. Following is the comparative chart based on the aforementioned façades. The façades will be compared based on five main aspects, Climate, Financial, Structural, environmental, and Installation Cost.

By examining the strengths and weakness of each façade, a conclusion will be drawn to understand which of the discussed façades is the most optimal for usage in the Indian context.

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Climate aspect

Water-based façades

• • • • • •

Creating subclimates.

Reducing the heat island effect.

Cooling the weather.

Increased humidity.

Difficult to use in all climatic conditions.

Identical functions in all seasons.

(Bastanfard, 2018)

Financial aspect

•

•

•

• •

Green façades

• • •

• •

Reducing the heat island effect.

Improving local air quality.

Humidity control to enhance comfort.

Difficult to use in all climate conditions.

Limitations in terms of plant selection based on location.

• • • •

• Reduced energy costs due to natural cooling and shading system.

Creates comfortable working environments in turn reducing turnover rates.

Incentivization of sustainable building practices.

High cost of maintenance.

Increased water cost.

Reduces the cost of cooling.

Easy repair and maintenance.

Higher cost of building.

Cost of highwater consumption.

Environmental aspect

Structural aspect

• •

•

•

•

•

•

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A water supply system is essential.

Designed to distribute water evenly.

Minimize water consumption and incorporate rainwater harvesting and recycling systems.

Proper drainage to prevent water buildup.

Designed to support the added weight extra structural reinforcements may be necessary.

•

The soil and other necessary items required for a green façade add to the already existing weight of the building.

Containers or pockets in which plants are grown are the typical support structures for a medium-sized planting bed.

An irrigation system is essential for delivering water to plants.

•

• •

•

•

• • • •

Cost of installation

Absorbs and filters pollutants.

Ameliorating the air.

Improves atmospheric conditions and creates healthy microclimates.

Could potentially be an insect breeding ground if not maintained.

Possibility of water freezing during the cold seasons.

•

The cost of installing a water façade in India can vary wildly based on various factors.

However, to provide a rough estimate, the average cost ranges from approximately INR 1,500 to INR 6,000 per sq. ft. which equates roughly to INR 16,150 to INR 64,600 per sq. m.

Revives the green space in the city.

Absorbs and filters the pollutants.

Improves atmospheric conditions.

Possibility of generating odour.

Possibility of inviting insects.

•

The installation cost of green facades can vary based on several factors including the size and complexity of the project. To provide a general estimate, the installation cost can range from INR 16,150 to INR 43,000 per sq. m. However, this is a very broad estimate and the actual cost can vary widely.

Microalgae façades

•

• •

•

Biochar based façades

• •

•

Highly efficient at capturing carbon dioxide from the atmosphere.

Continuous production of oxygen.

Provides shading and evaporative cooling.

Visually and aesthetically pleasing.

•

Carbon sequestration properties.

Effective insulation and thermal regulation.

Capable of retaining moisture and releasing it slowly to manage humidity levels.

•

•

•

• • •

Increasing value in the market.

Higher cost of creation due to lack of technology in many countries.

Requires experts for repair and maintenance.

•

Regular maintenance is required.

Energy savings through lower utility bills.

Durable and resistant to decay.

Property value enhancement.

•

• • •

•

•

•

Possibility of using it as a loading wall.

Increased weight of the building.

Obstructing the visual structure.

Creates the penumbra effect due to reflection.

•

Support structure is made from stainless steel, aluminium, or corrosionresistant materials.

Attachment can be done via fasteners, clips, brackets, or other attachment methods.

The panels should be lightweight and suitable for vertical installation.

A waterproofing layer is necessary.

•

• • •

•

•

•

•

The cost of installation varies significantly based on various factors but to provide a rough estimate the installation can range from INR 21,500 to INR 86,000 per sq. m.

•

The installation cost varies significantly based on several factors but to provide a rough estimate, the installation cost can range from INR 21,500 to INR 86,000 per sq. m.

Filters pollutants.

Carbon dioxide absorption.

Enhances the air quality.

Managing rainwater.

Acts as a carbon sink, capturing and storing carbon for extended periods.

Captures indoor pollutants such as volatile organic compounds and other harmful substances.

Reduces the need for heating and cooling due to its insulation properties.

Can absorb and retain rainwater.

(Source: Author)

This chart is depicted graphically using bar graphs, to create a clearer understanding of which of the following facades would work best in the Indian context. All four charts depict the four major aspects of comparison, with the numbers 0-2 depicting average, 2-3 depicting good, 3-5 depicting best.

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Climate Aspect Biochar Based Façade

Microalgae Façade

Green Façade

Water Based Bio Façade 0

0.5

1

1.5

2

2.5

Best

Good

Average

3

3.5

4

4.5

3

3.5

4

(Source: Author)

Financial Aspect Biochar Based Façade

Microalgae Façade

Green Façade

Water Based Bio Façade 0

0.5

1

1.5

2

Best

Good

Average

(Source: Author)

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2.5

Structural Aspect Biochar Based Façade

Microalgae Façade

Green Façade

Water Based Bio Façade 0

0.5

1

1.5

2

2.5

Best

Good

Average

3

3.5

4

4.5

(Source: Author)

Environmental Aspect Biochar Based Façade

Microalgae Façade

Green Façade

Water Based Bio Façade 0

0.5

1 Best

1.5 Good

(Source: Author)

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Average

2

2.5

3

3.5

Conclusion This research paper had the objective to identify and understand the currently available carbon absorbing Bio façades across the world, and to create a comparative analysis among them. This comparative analysis was created so as to discern which among the aforementioned facades would work best in Indian context.

Thus, taking into consideration the comparative analysis and the current economic and climatic conditions of India, through the process of bar graphs and studying the averages, it becomes evident that although slightly more expensive, the Biochar Façade is the most climatically, financially, structurally and environmentally sound. Since water facades although efficient, and highly helpful during hot climates are expensive to install due to the high costs of water and high maintenance. Green Facades are beneficial to the microclimate of a structure but its cost of structural support is high, and Microalgae façades despite being a highly capable and efficient method of carbon absorption is a newer and more unfamiliar technology. This would also require experts familiar with the technology itself and material which might not be abundantly available in India. Biochar façade is made by burning biomass like secondary agricultural and forestry offcuts which are abundantly available in India, in a lowoxygen environment through a process called pyrolysis, which is why their production will be efficient, also it is a light weight façade and can thus be easily installed on old structures as well as new, making it the most adaptable form of bio façade amongst the ones discussed. Thus, it is understood that the most efficient and durable carbon absorbing bio-façade option that can be used on a large scale in Indian cities today is Biochar Based Façade.

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References Bastanfard, M. (2018). Controlling Air Pollution with the Use of Bio Facades (A solution to Control Air Pollution in Tehran). The Monthly Scientific Journal of Bagh-E Nazar, 15(65).

El-Mahdy, D., & Youssef, A. K. (2022). OPTIMIZATION OF AN ADAPTIVE ALGAE FAÇADE BASED ON SOLAR RADIATION SIMULATION. International Journal of Computational Methods and Experimental Measurements, 10(4). https://doi.org/10.2495/CMEMV10-N4-314-328 Fytrou-Moschopoulou, A. (2013). The BIQ House: first algae-powered building in the world. BuildUp. Hahn, J. (2021). Atmospheric CO2 is “our biggest resource” says carbon-negative plastic brand Made of Air. Dezeen Magazine, June.

Hanafi, W. H. H. (2021). Bio-algae: a study of an interactive facade for commercial buildings in populated cities. Journal of Engineering and Applied Science, 68(1). https://doi.org/10.1186/s44147-021-00037-5 Hashimoto, K. (2019). Global Temperature and Atmospheric Carbon Dioxide Concentration. https://doi.org/10.1007/978-981-13-8584-1_3 Patarlageanu, S. R., Negrei, C., Dinu, M., & Chiocaru, R. (2020). Reducing the carbon footprint of the bucharest university of economic studies through green facades in an economically efficient manner. Sustainability (Switzerland), 12(9). https://doi.org/10.3390/su12093779 Pearson, P. N., & Palmer, M. R. (2000). Atmospheric carbon dioxide concentrations over the past 60 million years. Nature, 406(6797). https://doi.org/10.1038/35021000 Rezazadeh, H., Salahshoor, Z., Ahmadi, F., & Nasrollahi, F. (2022). Reduction of carbon dioxide by bio-façades for sustainable development of the environment. In Environmental Engineering Research (Vol. 27, Issue 2). https://doi.org/10.4491/eer.2020.583 SAMEH KAMAL ELDIN, M., & HEDEK IBRAHIM, S. (2021). The role of bio facades in energy conservation. International Journal of Architectural Engineering and Urban Research, 4(2). https://doi.org/10.21608/ijaeur.2021.231354 Sheweka, S. M., & Mohamed, N. M. (2012). Green facades as a new sustainable approach towards climate change. Energy Procedia, 18. https://doi.org/10.1016/j.egypro.2012.05.062

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