From Enea an index to calculate the economic and environmental sustainability of insulators

22/05/2023 – I insulating materials that can be used in the construction of a thermal coat are many. To date, the references for the choice are the industry standards but very often we are guided by economic assessments.

How would the design choices regarding energy efficiency change if it were possible to evaluate the energy, economic and environmental impact of an insulating material in advance?

From this idea comes an interesting study, currently in the preliminary stage, conducted by AENEAS which led to the formulation ofYES, the Economic and Environmental Sustainability Index which allows you to calculate the energy, economic and environmental impact of the different insulating materials used in the thermal coat, according to the type of building and the climatic zone.

To better understand the function and the advantages deriving from the use of this indicator, we interviewed the authors of the research, Dominic Palladino e Flavio Scrucca.

The origins of research

How and why was this study born?

The study was born in an attempt to correlate the energy, economic and environmental aspects for an evaluation of integrated sustainability of thermal coats for the redevelopment of buildings. The aim is to highlight how this integrated sustainability is closely linked to the choices of a designer and how it could undergo variations if aspects other than the economic ones were taken into consideration.

What is the Index of Economic and Environmental Sustainability (ISEA) and what is it for?

YES it is an index which, with the same energy consumption, allows both the economic and the environmental aspects to be taken into account when creating a thermal coat with a generic insulator. Although this indicator has been defined by adopting specific assumptions and simplifications (such as considering only some phases in the production and installation of the material), allows for comparisons among the various insulating materials considering both the cost for its installation and the environmental impact that its production has.

What are the normative and/or technical references for choosing an insulator today?

To date, when the building envelope is redeveloped with a thermal coat, it is necessary to respect the minimum requirements in terms of thermal transmittance o other building dispersion parameters, defined in the interministerial decree of 26 June 2015 (“Application of energy performance calculation methodologies and definition of the prescriptions and minimum building requirements”) in the interministerial decree of 08/06/2020 (“Requirements technicians for access to tax deductions for the energy requalification of buildings – so-called Ecobonus”), as well as compliance with the minimum environmental criteria set out in the ministerial decree of 11 October 2017.

What type of materials did you run the simulations on? On what basis were these materials chosen rather than others?

It was decided to choose both most common materials both natural and more sustainable materials, although less widespread or not yet used for this type of application. For the purposes of the study, the choice of the materials was purely technical and linked to the availability of the same within the software used for the LCA analysis, so as to have a single source of reference for the evaluation with a view to maximum comparability of the results.

Simulations made to determine the ISEA

What type of simulation did you carry out and on the basis of which calculation methodology?

All the energy simulationswhich formed an integral part of the database for environmental and economic assessments, were conducted according to the standard calculation in accordance with current technical legislation, i.e. the UNI TS 11300. This calculation method provides for an average monthly energy balance and is the same adopted in the drafting of the Energy Performance Certificates.

Which factors did you take into consideration and which ones did you discard?

For the purposes of this work it was decided to consider only redevelopment interventions of the vertical opaque component of the building, thus excluding interventions on the foundation and roof slabs and on the transparent component of the envelope. This choice is based on the fact that the most widespread redevelopment interventions are precisely those concerning the insulation of the external vertical walls.

What emerged from the simulations?

The most interesting thing emerged from the simulations is the evidence that, if the environmental aspect were also considered in the choice of insulating materials, attributing to it a “weight” in the evaluation equal to that of the economic aspect, the convenience of more sustainable materials would become comparable with that of traditional materials, especially in colder climatic areas thanks to the greater energy savings that could be obtained in these areas.

How to interpret the search results

What is the connection between energy-economic and environmental impact in an insulating material? How do these three factors, depending on the weight associated with them, influence the choice of product to use?

These three factors they are strictly connected to each other and depending on the weight which is attributed to each of them the choice of a material can also vary significantly, as highlighted in the study. Defining carefully on the basis of solid evidence the weight to be attributed to these three factors (energy, economic and environmental) is, as described in the work, the still open challenge that will be the subject of further studies and insights.

How is the energy aspect influenced by the “economic return” and the “environmental impact return” evaluated in the context of the simulations?

In this work several assumptions and simplifications have been made. One of these is having assumed that, regardless of the insulation adopted, the minimum requirements of the DM 26/06/2015 were met, in order to compare the materials with the same performance. This led to the use of a different thickness of the insulators investigated for the same energy consumption of the post-construction building. The different amount of insulation used (calculated on the basis of the conductivity and density of each material) has resulted in a different cost and environmental impact, resulting in more or less high economic and environmental payback times.

How to use the indicator

How should the ISEA indicator be interpreted and/or used?

The ISEA indicator makes it possible to integrate into a dimensionless value, weighing them appropriately, economic and environmental payback times of the different insulators. As defined, the lower the value of the indicator, the higher the integrated sustainability of the material, and vice versa. However, for the purposes of choosing the most sustainable material, rather than thinking in absolute terms, it is advisable to observe the trend of the comparison between the various materials, in order to verify the convenience or otherwise of one compared to the other.

The recipients of the research and future prospects

Who are the results of this preliminary research aimed at and why? For which type of intervention will it be more appropriate to use the indicator: for new constructions or energy requalification?

Being an indicator that is based on purely technical aspects and data, the indicator is more facing ad industry experts and technicians. The indicator was developed considering energy requalification interventions, but its extension also for new buildings cannot be excluded a priori. In fact, having all the data required for calculating the indicator available, it can potentially be used for any type of application and any material.

Are the results obtained already applicable to real cases?

The study carried out represents only a preliminary research aimed at defining a method for combining energy aspects with economic and environmental ones in a synthetic indicator. The calculation methodology used is the one in force and adopted when a building is redesigned energetically; however, it is necessary to further study the definition of this indicator with the main purpose of adopting the most suitable coefficients to combine the economic and environmental aspects.

Nonetheless, the indicator could already provide useful indications for the purpose of choosing a material, should one wish to consider both the economic and environmental aspects, attributing equal weight to them in the assessment.

What is the next step you will take and what is the final goal you would like to achieve?

The next step is to further investigate this indicator, perhaps increasing the level of detail in the modeling of all the production and installation phases of the insulating material and trying to implement solutions that allow for a more appropriate evaluation of the aspects of circularity and efficiency of the resources associated with various materials/life cycle stages.

Further study may also concern the possibility of defining in a more appropriate and specific way the weight that should be attributed to both the economic and environmental aspects for the purposes of their integration in the indicator. Furthermore, the possibility of developing a further study of the indicator starting from the real consumption of the building instead of the standard ones cannot be excluded.

The complete results have been published and can therefore be consulted in the online journal Sustanaibility.

Source: Le ultime news dal mondo dell'edilizia by

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