Functional Adaptive Nano-Materials and Impact of External Insulation
Contents 1. Introduction... 1 2. Methodology... 2 2.1. Base case models... 2 2.2. Building model according to building codes... 3 3. Simulations... 3 4. Results... 4 4.1. Generic tendencies... 4 5. Comparison between the building cases... 5 6. Conclusion... 7 Contents of Figures Figure 1: 3D view of the multifamily building designed... 2 Figure 2: Thermal zoning of one of the four stories of the building... 3 Figure 3: Impact of wall insulation on the energy demand of a multifamily building in Spain... 4 Figure 4: Impact of wall insulation on the energy demand of a multifamily building in Germany... 4 Figure 5: Impact of wall insulation on the energy demand of a multifamily building in Sweden... 5 Figure 6: Difference between the energy demand with and without insulation in Spain... 6 Figure 7: Difference between the energy demand with and without insulation in Germany 6 Figure 8: Difference between the energy demand with and without0 insulation in Sweden... 6 Figure 9: Evolution of the insulation material thickness required to achieve a U-value of 0.18 depending on its thermal conductivity... 7
1. Introduction The objective of this document is to highlight the impact of external wall insulation, and in particular, of the insulation material developed within the scope of FoAM-BUILD on the energy performances of buildings in Europe. 1
2. Methodology 2.1. Base case models New and existing multifamily building models were designed for three countries in Europe: Spain, Germany and Sweden. These building models take into account the most common characteristics for the envelope, the equipment and usage scenarios for each country. The standard multi-family building was designed with the software Alcyone which is the graphical model software of Pléïades+COMFIE1, the dynamic thermal simulation software used in this work (Figure 1). Figure 1: 3D view of the multifamily building designed The building has a 12 m * 36 m floor area with 4 storeys, which each have a ceiling height of 3 m. The building is detached. All the floors are identical; one of them is detailed in Figure 2. There are 9 thermal zones on each storey: 2 studios of around 25 m 2 with one window, 2 one-bedroom apartments of approximately 40 m 2 and two windows, 4 two-bedroom apartments of approximately 55 m 2 each and between three and five windows, 1 corridor which is not heated. 1 http://imap.izuba-energies.com/logiciel/pleiadescomfie 2
Figure 2: Thermal zoning of one of the four stories of the building 2.2. Building model according to building codes In a second phase, these base models were upgraded in order to fulfil the energy requirements of the three countries building codes both today and in the future 2345 (2016-2020). There are therefore up to six building models per country: the two base models for new and existing buildings called Existing base and New base, and their upgrade that fulfils the current building code (Existing retrofit and New thermal regulation) and a predicted future building code (Existing better retrofit and New improved). For all these models the whole building envelope, equipment and usage scenarios were upgraded. 3. Simulations In order to investigate the unique impact of external wall insulation, in all the cases described above three simulations were conducted. The first simulation was performed without insulation on the external walls, the second with classic ETICS with 10 cm of standard 0.035 W/(m.k) EPS and the last one with 10 cm of FoAM-BUILD 0.02 W/(m.k) EPS in the ETICS. 2 http://www.codigotecnico.org/images/stories/pdf/ahorroenergia/dbhe.pdf 3http://www.boverket.se/globalassets/publikationer/dokument/2012/bbr-engelsk/bfs-2011-26-bbr-eng- 9.pdf 4 http://www.enevonline.org/enev_2009_volltext/enev_2009_anlage_01_anforderungen_an_wohngebaeude.pdf 5 http://www.rehva.eu/publications-and-resources/hvac-journal/2011/032011/how-to-define-nearly-net buildings-nzeb/ 3
4. Results 4.1 Generic tendencies As only the impact of insulation is studied here, the energy demand of the building for heating is studied for the three buildings so that the systems can be factored out of the results. The first three figures (Figure 3, 4 and 5) show the energy demand of the building for each country. The energy demand of the building without thermal insulation on the external walls is higher than that of a building with insulation. But the difference in energy demand between a wall insulated with 10 cm of standard 0.035 W/(m.k) EPS and a wall insulated with 10 cm of FoAM-BUILD 0.02 W/(m.k) EPS as shown in these figures is small. It is very important to have good insulation of the external wall, (i.e. with 10 cm of a standard EPS, corresponding to a thermal resistance of 2.9 (m².k)/w). However, it is difficult to assess the impact of an even better insulation on these figures, for example, an insulation with 10 cm of a FoAM-BUILD EPS, corresponding to a thermal resistance of 5 (m².k)/w. Figure 3: Impact of wall insulation on the energy demand of a multifamily building in Spain Figure 4: Impact of wall insulation on the energy de- mand of a multifamily building in Germany 4
Figure 5: Impact of wall insulation on the energy demand of a multifamily in Sweden 5. Comparison between the building cases Figures 6, 7 and 8 show the differences in terms of kwh between the non-insulated version of the building model and the versions with 10 cm of standard and FoAM-BUILD EPS. It holds true for all cases that the more energy efficient the building is, the more important it is to insulate it well. For instance, figure 6 shows only a 20 % difference between the buildings with and without insulation. But for the version of the building with a very good retrofit, the difference between the building models with and without insulation goes up to 40%. When the building is badly insulated and has high air permeability, insulating the walls does not have a great impact on the energy demand because the heat Coatings allow a faster implementation, product inside the building has many other ways to leave it (air renewal, roof, basement, windows, etc.). When all other parts of the building are highly efficient, the insulation of the walls becomes essential in order to prevent savings and easier work. energy losses. The last column (in green) of the figures shows the difference in energy demand between the building models with standard and FoAMBUILD EPS. The same results apply here: the better the building s energy efficiency, the greater the need for good insulation (for instance a 0.02 W/(m.K) EPS). Using 10 cm of a very good EPS on a very energy-efficient building leads to a reduction in the energy demand of 5-10 % (compared to a standard EPS). The increasingly strict requirements of the national thermal regulations will lead to a rising demand for efficient insulation materials, if the thickness of the insulation material must be maintained at current values of around 10 cm in cold and temperate climates. 5
Figure 6: Difference between the energy demand with and without insulation in Spain Figure 7: Difference between the energy demand with and without insulation in Germany Figure 8: Difference between the energy demand with and without insulation in Sweden 6
6. Conclusion The results of these simulations show that the insulation material developed in the FoAM-BUILD project will be very useful in the near future as it will greatly reduce the thickness of the insulation needed to fulfil the energy requirements of 2020. For instance in the case of the retrofitting of existing buildings in Germany with regard to the horizon of 2020, the U-value of the wall is expected to be near 0.18 W (m².k). As demonstrated in Figure 9, only 10 cm of 0.02 W/(m.K) EPS are needed to achieve this value, but with standard insulating material up to 20 cm of EPS would be needed. Because of a 50% decrease in thickness, it will be easier to transport the ETICS and to install them on site. This also means that the building will take up less space while still allowing for a reduction of the energy consumption, which is a crucial factor in cities with high building densities, as is the case in Europe. Figure 9: Evolution of the insulation material thickness required to achieve a U-value of 0.18 depending on its thermal conductivity 7