Human Practices

As we have progressed in the design of our project, we determined the priorities we had for our project. The key priorities, or values, we had for the HESTIA product shaped our design considerations and our stakeholder approach. Here are the eight values we had in mind as we designed and engineered project HESTIA:

• Biodegradability: We want our insulation material to have a minimal impact on the environment. Every material in the end product should be non-accumulative and be able to circulate within the ecosystem harmlessly.

• Sustainability: We want to see our product to be produced through recycled materials and itself being recycled many times over, overall contributing to a circular economy.

• Modularity: Modern insulation materials have to fulfil a multitude of requirements. Our protein coating has to be able to functionalise the aerogel in more than one way.

• Ease of Application: For construction purposes, insulation materials need to be sturdy and easy to handle. Making the application of the product as easy as possible is an important objective for end-user satisfaction.

• Affordability: Even the most ingenious idea has no economic value without financial feasibility. We need our product to be as competitive in price as it is in performance.

• Thermal Insulation Efficiency: Energy efficiency as a concept depends on efficient thermal insulation. A sign of a society that is conscious of its energy use, is attention to insulation.

• Safety: To this day the demolishing of old buildings can cause health risks due to old and toxic materials being exposed to contact again. HESTIA absolutely needs to be non-toxic and should pose no acute or long term health risks whatsoever.

• Longevity: For construction, a happy customer is one that doesn’t need to see the contractor again and again. Longevity is important for any construction material, lest it needs to be replaced more and more frequently, increasing maintenance costs and resource consumption.

HESTIA sits in a unique intersection of synthetic biology, material science, construction and energy strategy. We wanted to utilise this intersection to gather a broad range of perspectives and to understand what each stakeholder expects from an insulation material within the context of their objectives and interests.

We have developed our stakeholder approach to reflect this diversity while maintaining an overall direction and purpose. As such, we have chosen to perceive our stakeholders through the lens of the supply chain. From raw material considerations to possible end usage implementations, we have considered any substantially involved actor as a possible stakeholder, and engaged them in accordance with their needs and desires. We have engaged with:

• researchers and insulation producers to understand the needs of an insulation material and how it is produced,

• construction companies and architects to see how these materials are used and applied for different purposes,

• SDG accelerators and policy makers to assess how these materials plays a part in a sustainable energy strategy as an important asset,

• Ordinary citizens and homeowners to understand their wishes and concerns about safety and cost-efficiency.

This approach helped us understand and design our insulative aerogel under all possible contexts.

Proposed Implementation

The future implementation of our insulation material was a guiding consideration in our Human Practices, and is the main motivation behind our supply chain model. The Proposed Implementation therefore was the major field where the stakeholder feedback was integrated. The raw material choice, the strategic applications within a building and the addition of recycling systems as a service were some of the major Integrated Human Practices contributions to the Proposed Implementation.

Click to discover the Proposed Implementation Page

Supporting Entrepreneurship

Selling a product means selling an idea and a process. Our Human Practices work was crucial to understand the current state and the needs of the insulation market. Understanding the production process and also the application in construction and architecture helped us create a sustainable and feasible business model valid assumptions and strategies.

Click to discover the Supporting Entrepreneurship Page

Sustainable Development Impact

Sustainability was a chief objective in our initial project design. Choice of cellulose as the aerogel material and functionalising this specific material itself was also due to this concern. Thanks to our Human Practices work we learnt that the amount of energy used to produce the material was equally important, and coupling a recycling service to the proposed implementation and the business model would be a necessary design element.

Click to discover the Sustainable Development Impact Page

Education and Communication

Consulting stakeholders is naturally linked to educating the society and ourselves while communicating the core idea of our project. Our Model United Nations focus group also linked the Education & Communication and Human Practices further, as we both learnt the concerns and thoughts of our fellow university students while also pushing deeper awareness into synthetic biology and energy consumption. It also introduced the group-specific method approach we had for the Education & Outreach to the Human Practices.

Click to discover the Education and Communication Page

Through our discussions with the researchers in EMPA, we learnt that the exact classification of a cellulose aerogel is debated in certain points, mostly on pore size and porosity (percentage of volume occupied by pores). While nanoporous materials are unanimously considered as aerogels, macroporous materials are a matter of debate, with a sizable section of the scientific literature considering these materials as aerogels as well.

The most porous cellulose aerogels are usually produced through a TEMPO Oxidation and Critical Point Drying process. While the ideal choice, we deemed the process to be stretching our safety concerns for the chemical composites involved. Instead, we opted for an easier process of a cellulose suspension being gelated and lyophilised. This process does give us macropores and a lower porosity, yet the ordered cellulose structure as a porous structure remains the same, and still works for the protein coating attachment proof-of-concept.

Stakeholders involved: EMPA

Through both research and stakeholder consultation, we realised the importance of hydrophobicity for not just construction purposes but also for the aerogel itself. Aerogels can lose as much as half their volume after the Critical Point Drying process if they are not hydrophobic.

In order to address this we added a silk protein domain, the N[As]4C recombinant consensus sequence from the green lacewing species Mallada signata, to the initial protein coating design, resulting in the 01a mSA-silk-CBD construct. The N[As]4C can polymerize and form a hydrophobic biofilm, which then binds to the surface of the cellulose aerogel.

Stakeholders involved: EMPA

Thanks to our consultation with EMPA, we understood that any application of cellulose aerogels as serious competitors to the existing silica aerogel applications must have a competitive thermal conductivity / λ-value to be considered in the first place.

As such, in accordance with the feedback we got from EMPA, we decided to nominally aim for a λ-value below 0.020 W/mK for our project design. In fact, this value is an overall objective in the material science community for the cellulose aerogels, with one study even seeing 0.018 W/mK1. This aim is set due to the fact that silica aerogels can have λ-values as low as 0.015 W/mK2, while more conventional materials struggle to reach the 0.020 W/mK mark.

A competitive λ-value is also important for recognition by the federal government and the scientific community. The Swiss Federal Office of Energy subsidises insulation material projects based on the λ-value they reasonably aim for, as it is the chief criterion as an asset for the energy efficiency pillar of the national energy strategy. For the scientific community, an intersection between high insulative performance and sustainability is a chief area of interest that can lead to further research.

Stakeholders involved: EMPA, SFOE

Seeing the production process of both silica aerogels and glass wool was instrumental for the industrial scale production in our Proposed Implementation. While no industrial scale production method exists for cellulose aerogels, we can nevertheless look at the production methods of similar methods and infer a way forward worth investigating in the future.

Silica aerogels are produced on an industrial scale by embedding the hydrogel in insulative sheets, as the aerogels themselves are fragile. The sheets are then rolled up into cylinders and Critical Point Dried in big cylindrical dryers. The λ-value is naturally higher in the end product, but the trade-off for the ability to apply the material is usually tolerable.

For our purposes, we hypothesised a process inspired by the current industry practice: embedding the cellulose hydrogel in cellulose sheets. Cellulose sheets are insulative materials already in use, and can be obtained from recycled cellulose sources. As the cellulose sheets also contain ordered cellulose comformations, our protein coating would still be a valid application. To match the amount of proteins needed to coat the sheets, we experimentally confirmed, with the input of the Protein Production and Structure Core Facility (PTPSP) experts, that the BL21(De3) E.coli strain was the best for the upscaling purposes.

Stakeholders Involved: EMPA

As explored in our Sustainability Impact Page, we were informed that the Canton of Vaud is rapidly running out of space to deposit construction material waste3. As such, it is expected that construction materials, especially material installations that need periodic renewal, with efficient recycling systems and services will be much needed.

Coupled with the highly inefficient rate of recycling in Switzerland, we decided to add a recycling service/system to our Proposed Implementation. This system will be based on collecting the used insulation material, separating the protein coating and the cellulose, and then producing regenerated cellulose aerogels or recycled cellulose sheets from the obtained cellulose.

Stakeholders Involved: ISOVER

Thanks to our discussion with the Canton of Vaud - DGE, we know that it is highly probable that upcoming legislation in the canton but also in Switzerland will introduce tighter regulations for highly energy consuming buildings, making renovation compulsory.

Equally, aerogels can achieve the same low thermal conductivity with considerably shorter material thickness compared to conventional insulation materials. This fact makes aerogels ideal for the renovation of old buildings, whose insulation must be done externally while still not overreaching into the pedestrian sidewalks or losing outer wall details.

This is why we decided to focus on the use of our product primarily on renovation projects. We believe it is as important to make the old buildings energy efficient as constructing new buildings to be energy efficient, and it is a field of application where aerogel insulation truly shines.

Stakeholders Involved: Canton of Vaud, EMPA, ISOVER

Thermal bridges are points in a system or construction where the flow of heat can take place more easily compared to the rest of the system. For the thermal insulation of buildings and thermal envelopes, thermal bridges are serious shortcomings as they compromise the energy efficiency by allowing the interior heat to easily escape.

A frequent case of thermal bridges in buildings is in the windows. Usually, there will be a difference in distance between the edge of the outer wall and the positioning of the window. If not insulated properly, heat can flow out easily from the surface created by this distance. The issue with this specific surface is that conventional insulation materials are too thick to be placed in there, or else the windows need to get considerably smaller.

As pointed out by ISOVER; aerogels, requiring a lot less thickness, would be a good solution to this problem. Since the aerogel can be applied as a thin layer, the thermal envelope of the building would be perfected with minimal use of material, while aesthetic design choices can be maintained. We consider the use of the HESTIA product to combat undesired thermal bridges as an excellent example of cost-efficient and strategic application.

Stakeholders Involved: ISOVER

Through our consultation with architects and the RTS construction site visit, we decided that it would be wise to couple the protein coated cellulose aerogel with a double wall system for conventional insulation applications.

A double wall system (also known as cavity wall) is a wall construction technique where two layers of walls are constructed parallel to each other, with a cavity in between. Either air or an insulation material is placed in between the walls. Especially when coupled with (wooden) supports, the double wall system alleviates mechanical stress from the insulation material. For certain insulation materials, a double wall application heightens the sound insulation properties as well.

We believe such an application would be ideal if the HESTIA product is to be used. The setup would be ideal for the aerogel sheets as it would complement the thermal insulation and reduce mechanical stress.

Stakeholders Involved: RTS

Minergie is a Swiss construction label focusing on energy efficiency, supported by the industry, the local governments and the federal government. It emphasises on a holistic approach to energy efficiency: A comprehensive thermal envelope/shell, controlled air flow and a minimum usage of renewable energies for heating. Depending on the desired efficiency, Minergie has the following grades: Minergie, Minergie-P, Minergie-A, ECO and more.

We imagine and recommend the use of HESTIA in Switzerland within the context of the Minergie label. Efficient insulation is important, but it can only do so much on its own. It is through comprehensive approaches that we can bring the best possible performance in an insulation material and achieve remarkable success in energy efficiency. Plus, while Minergie doesn’t promote any one insulation material, it does track the environmental impact of those materials. As we aim for a more sustainable insulation material, we see it as essential for a recognition from Minergie as an important step for HESTIA’s future.

Stakeholders Involved: ISOVER, RTS, Canton of Vaud

The Society of Swiss Architects and Engineers (SIA) Norms are a set of standards that have become the generally accepted rules for construction in Switzerland. While not laws by themselves, the SIA Norms are usually used as attachments and baselines to many construction contracts, and their technical guidelines are important points, filling in the gap of national regulations caused by the decentralised approach of Switzerland in construction regulation. We have been informed of these norms repetitively through different stakeholders.

For ensuring compliance with the Swiss law, we aimed to make sure that our insulation material was in accordance with all the stipulations of the SIA Norms on insulation. Two norms were paramount for this objective:

This norm provides an exact definition of what an insulation material is: Materials expected to reduce heat transfers whose insulative properties stem from their chemical nature or physical structure. Norm 279 also establishes a maximum thermal conductivity value of λ = 0.1 W/mK for a material to be considered as insulative.

The norm equally gives instructions on packaging information, testing methods and quality control, all important for our Proposed Implementation. The declared λ-value, λD, from a company must be derived from a calculated lambda value (λ 90/90), obtained from a control within the factory production, valid for 90% of the population with a confidence interval of 90%, with additional environmental conditions in mind.

In annex, the expected λ-values of certain insulation materials are provided, acting as a second quality check. For our purposes, we saw that the λ-value of silica aerogels are on average λ = 0.024 W/mK, while company specific samples can go as low as 0.016 W/mK. This verified the approximate 0.020 W/mK goal suggested by EMPA, and led our thermal conductivity analysis.

The Norm requires all buildings to be as airproof as possible, or at least have controllable air flow, so as to not compromise the thermal envelope of the building. This is to be achieved through insulating not just the walls but also the floors and the roof as well.

Norm 180 equally specifies certain U-values to be targeted for the entire building during summer and winter. The U-value is the coefficient of thermal transmission [W/m^2*K], defined as the quotient of thermal flux per unit surface of the material. These requirements are important for construction design purposes.

Most importantly for our project, the norm dictates that for protecting the organic insulation materials from deformation, the relative humidity of the air inside the building must remain within 30% - 70% for an altitude of 800m. As a local example, the city of Lausanne is 526m above sea level, so this condition holds for our purposes.

Stakeholders Involved: ISOVER, RTS

Through our discussions with the Canton of Vaud DGE, we have learnt about the current state of the construction sector in the canton and Switzerland in general. There is a significant saturation in the market, making the introduction of HESTIA into the market as a start-up as an ill-conceived idea. The recommendation we got was to sell the idea to existing actors on the market instead.

Stakeholders Involved: Canton of Vaud

Market analysis data is not necessarily easy to achieve for outsiders. Thanks to stakeholder consultation, we managed to get critical data about the insulation market, and especially about the size and the allocation of resources within the current aerogel insulation market.

Stakeholders Involved: EMPA, ISOVER