RESIDENTIAL BUILDING ENERGY SURVEY AND IMPROVEMENT PROPOSAL

Transcription

1 DEPARTMENT OF TECHNOLOGY AND BUILT ENVIRONMENT RESIDENTIAL BUILDING ENERGY SURVEY AND IMPROVEMENT PROPOSAL HEAT STUDY AND IMPROVENT OF RESIDENTIAL BUILDINGS Ricardo Moya Jaraba September 2010 Master s Thesis Master Programme in Energy Systems Examiner: Mathias Cehlin Supervisor: Roland Forsberg

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3 PREFACE I want to say thanks to University of Zaragoza for give the chance to be here in Gävle, Högskolan i Gävle for accept me as student and make easy to me finding an interesting project and teach me a lot things in the Master Programme in Energy Systems and of course to Gavlegårdarna for give me the opportunity to work as engineer with them. Thanks for all the support of Roland Forsberg my supervisor in the Högskolan i Gävle, teachers Mathias Cehlin and Björn Karlsson and Anders Holmsten my supervisor in Gavlegårdarna. I m grateful for the support of my family, parents and brother and for my classmates of the masters for all this year. I have a special gratittud to my classmate Victor Guitierrez not only for the project for all the moments lived together, Borja Vaquero the third Jäger-musketeer and big friend, Jenifer Vallejo and Maria Nikolaidou only to say thanks for have luck to meet them and be part of their lives. Faye Tang was every second in my mind when I was writing this project; she was my inspiration and be with her was my goal. Thank you.

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5 SUMMARY This Project tries to solve a problem giving some proposals for that of some buildings that waste a lot of energy in their use. For that is necessary to do an energy survey for know in which aspects the buildings are working bad or in which can be improved. This objective is also of the EURHONET retrofitting together project that this project talks to and is a part of it. In the objective of reduce energy waste of the building is also the objective of reduce the bill in the energy consumption and of course in the environmental view, buildings that spend less energy are better for the environment and this topic the company Gavlegårdarna cares about, and Sweden country too. For notice the impact of the proposal and the improvement of this it was studied the buildings their consumption and their construction, the last one with a lot of difficulties due to the oldness of the buildings and the lack of information about plans and internal structure. But it can give a good approximation of the real consumption and the savings of the proposals mentioned in the project. In the project can be find a global view of the energy of Sweden and the rest of the world and of course a presentation of the buildings and the presentation of Gavlegårdarna AB and EURHONET and the retrofitting together project. The energy survey of all losses in the biuldings and also how they was calculated. Then it can be find the proposal and the impact in the building with a investment study of them. Finally a discussion and conclusion about all the project.

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7 LIST OF CONTENTS 1 INTRODUCTION Global view of planet situation Global view of Sweden s situation Energy consumptions Energy use in residential and service sector Electricity District heating Gavlegårdarna AB Company EURHONET Buildings studied Location Areas Building Structure Foundations External walls Windows and doors Ceiling to outside Ceiling to attic store Attic store Heated Volume Glaciärvägen Glaciärvägen 23 and Pinnmovägen Purpose Limitations Method... 37

8 2 THEORETICAL FRAMEWORK District heating system Gävle climate and Degree Days Energy Survey Energy Ratio Energy Survey: Consumption Energy Survey: Losses U-Values Calculation Foundation External Walls Windows and doors Ceiling to outside Ceiling to attic store Thermal photography Windows and doors improvement Ceiling to attic improvement Solar Energy proposal Investment study Net Present Value Payback... 56

9 3 PROCESS and RESULTS Energy Survey: Consumption Summary information District heating Electricity Total Energy Cost District heating Electricity Total Cost Energy Survey: Losses Foundation External walls Store Wall Concrete Wall Concrete-Wood Wall Curtain Wall Summary total losses of external walls Windows and doors Ceiling to outside Ceiling to attic store Summary Total looses Conduction losses Ventilation losses Total losses... 80

10 3.3 Windows proposal Summary information Energy report Energy looses Energy Savings Economic report Savings in energy cost Investment study Ceiling to attic store proposal Summary information Energy report Energy losses Energy savings Economic report Savings in energy cost Investment study Solar Energy proposal Summary information Energy report Economic report DISCUSSION Energy survey: consumption Energy survey: losses Windows proposal Ceiling to attic store proposal Solar Energy proposal Energy consumption with proposals

11 5 CONCLUSION REFERENCES APPENDICES Buildings Plans Glaciärvägen Glaciärvägen Pinnmovägen Sätra District Heating Net Plan Energy Consumption Tables Year Year Solar Energy Plans Investment study year by year Windows proposal Ceiling to attic store proposal Solar Energy proposal Resume of Materials

12 LIST OF FIGURES Figure 1. World energy supply 1 Figure 2. Global primary energy supply Figure 3. Global energy use by sectors Figure 4. Supply of energy in Sweden Figure 5. Use of energy in Sweden Figure 6. Use of energy in Sweden Figure 7. Energy use Figure 8. Energy use with loses in their sectors 6 Figure 9. Final Energy use in residential Figure 10. Electricity use in Sweden by sectors Figure 11. Per-capita electricity production by types of production Figure 12. District heating use Figure 13. Energy input to district heating systems Figure 14. Use of bio-fuels in district heating plants Figure 15. EURHONET companies 13 Figure 16. Building picture, Summer (I) 15 Figure 17. Building picture, Summer (II) 15 Figure 18. Building picture, Summer (III) 16 Figure 19. Building picture, Summer (IV) 16 Figure 20. Building picture, Winter (I) 17 Figure 21. Building picture, Winter (II) 17 Figure 22. Gävle in Sweden 18 Figure 23. Sätra in Gävle 19 Figure 24. Buildings in Sätra 19 Figure 25. Heat Volume ground floor Glaciärvägen Figure 26. Heat Volume residential floors Glaciärvägen Figure 27. Heat Volume section Glaciärvägen Figure 28. Heat Volume ground floor Glaciärvägen 23 and Pinnmovägen Figure 29. Heat Volume residential floors Glaciärvägen 23 and Pinnmovägen Figure 30. Heat Volume section Glaciärvägen 23 and Pinnmovägen 26 35

13 Figure 31. Temperatures of Gävle, Normal, 2008, 2009 and 2010 until April 41 Figure 32. Heating Degree Days of Gävle, Normal, 2008, 2009 and 2010 until April 43 Figure 33. Heating Degree Days of Gävle, per year Normal, 2008, 2009 and 2010 until April 43 Figure 34. Foundation losses 47 Figure 35. Ceiling losses 49 Figure 36. Thermal picture (I) 50 Figure 37. Thermal picture (II) 51 Figure 38. Thermal picture (III) 51 Figure 39. Thermal picture (IV) 52 Figure 40. Thermal picture (V) 52 Figure 41. Thermal picture (VI) 53 Figure 42. Thermal picture (VII) 53 Figure 43. Energy used of General district heating in Pinnmovägen group of buildings in years 2009 and Figure 44. Energy used of General district heating in Glaciärvägen group of buildings in years 2009 and Figure 45. Energy used in heating in Pinnmovägen group of buildings in years 2009 and Figure 46. Energy used in heating in Glaciärvägen group of buildings in years 2009 and Figure 47. Energy used in warm water in Pinnmovägen group of buildings in years 2009 and Figure 48. Energy used in warm water in Glaciärvägen group of buildings in years 2009 and Figure 49. Windows ventilation gap 81

14 LIST OF TABLES Table 1. Buildings requirements 14 Table 2. Areas of building Pinnmovägen Table 3. Areas of building Pinnmovägen Table 4. Areas of building Glaciärvägen Table 5. Areas of building Glaciärvägen Table 6. Total Areas of group of buildings 24 Table 7. Continuous foundation structure 25 Table 8. Store wall structure 26 Table 9. Concrete-Wood wall structure 26 Table 10. Concrete wall structure 26 Table 11. Curtain wall structure 27 Table 12. Ceiling to outside structure 27 Table 13. Ceiling to attic store structure 28 Table 14. Attic store walls structure 28 Table 15. Attic store roof structure 29 Table 16. External surface wall Glaciärvägen Table 17. Heat Volume Glaciärvägen Table 18. External surface wall Glaciärvägen 23 and Pinnmovägen Table 19. Heat Volume Glaciärvägen 23 and Pinnmovägen Table 20. Temperatures of Gävle, Normal, 2008, 2009 and 2010 until April 41 Table 21. Heating Degree Days in Gävle in 2008, 2009 and 2010 until April 42 Table 22. Heating Degree Days per day in Gävle in 2008, 2009 and 2010 until April 42 Table 23. Inside temperatures inresidential floors of the buildings 44 Table 24. Windows and doors areas per building 48 Table 25. District heating energy consumption in of the two groups of buildings in 2009 and Table 26. District heating energy consumption of each buildings in Table 27. District heating energy consumption of each buildings in

15 Table 28. District heating energy consumption in of the two groups of buildings per m² in 2009 and Table 29. Electricity consumption in 2009 and Table 30. Electricity consumption per meter square in 2009 and Table 31. Total Energy use for buildings in Table 32. Total Energy use for buildings in Table 33. Summary cost of district heating in Table 34. Summary cost of district heating in Table 35. Summary cost of electricity in Table 36. Summary cost of electricity in Table 37. Total cost of Building in Table 38. Total cost of Building in Table 39. Foundation losses in Glaciärvägen 21 for normal year, 2008 and Table 40. Foundation losses in Glaciärvägen 23 or Pinnmovägen 26 for normal year, 2008 and Table 41. Foundation losses in the three buildings for normal year, 2008 and Table 42. Store Wall losses in Glaciärvägen 21 in Normal year, 2008 and Table 43. Store Wall losses in Glaciärvägen 23 and Pinnmovägen 26 in Normal year, 2008 and Table 44. Store Wall losses in the three buildings in Normal year, 2008 and Table 45. Concrete wall losses per building in Normal year, 2008 and Table 46. Concrete wall losses in the three buildings in Normal year, 2008 and Table 47. Concrete-wood wall losses per building in Normal year, 2008 and Table 48. Concrete wall losses in the three buildings in Normal year, 2008 and Table 49. Curtain wall losses per building in Normal year, 2008 and

16 Table 50. Concrete wall losses in the three buildings in Normal year, 2008 and Table 51. Summary Total Energy losses External Walls losses in Glaciärvägen 21 in Normal year, 2008 and Table 52. Summary Total Energy losses External Walls losses in Glaciärvägen 23 and Pinnmovägen 26 in Normal year, 2008 and Table 53. Summary Total Energy losses External Walls losses in the three buildings in Normal year, 2008 and Table 54. Windows and doors looses per building in Normal year, 2008 and Table 55. Windows and doors looses in the three buildings in Normal year, 2008 and Table 56. Ceiling to outside looses per building in Normal year, 2008 and Table 57. Ceiling to outside looses in the three buildings in Normal year, 2008 and Table 58. Attic temperature in Normal year, 2008 and Table 59. Ceiling to attic store looses per building in Normal year, 2008 and Table 60. Ceiling to attic store looses in the three buildings in Normal year, 2008 and Table 61. Conduction losses in the three buildings in Normal year, 2008 and Table 62. Ventilation losses in the three buildings in Table 63. Total losses in the three buildings in year Table 64. Energy losses with new windows and doors in Normal year, 2008 and Table 65. Energy savings with new windows and doors in Normal year, 2008 and Table 66. Saving in energy cost with new windows and doors in Normal year, 2008 and Table 67. Investment Information in Windows and doors proposal 85 Table 68. NPV and Payback of the Investment of Windows and doors proposal 85

17 Table 69. Ceiling to attic store proposal 86 Table 70. Attic temperature with the ceiling improvement in Normal year, 2008 and Table 71. Energy losses ceiling to attic store with new ceiling in Normal year, 2008 and Table 72. Energy savings with new ceiling to attic store in Normal year, 2008 and Table 73. Saving in energy cost with new ceiling to attic store in Normal year, 2008 and Table 74. Investment Information in Ceiling to attic store proposal 91 Table 75. NPV and Payback of the Investment of Ceiling to attic store proposal 91 Table 76. Aquasol s solar collectors models 92 Table 77. Aquasol s solar collectors models areas 93 Table 78. Study of tilt in flat collector 93 Table 79. Flat collectors with 40º tilt 94 Table 80. Flat collectors with 90º tilt 94 Table 81. Total Energy of Flat collectors with 40º and 90º tilt 95 Table 82. Investment Information in Solar energy proposal 95 Table 83. NPV and Payback of the Investment of Solar energy proposal 95 Table 84. Total savings of the proposals in the buildings 101 Table 85. New consumption with proposal 101 Table 86. New consumption cost with proposals 102

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19 1 INTRODUCTION 1.1 Global view of planet situation The energy supply of the world is almost all by fossil fuels, around 80%, oil, coal and natural gas are the fossil fuels most used. Oil is the most important with 34% followed by coal, 26%, and natural gas, 21%. Renewable energy is finally getting importance too in the energy supply of the world with a percentage of 13% including hydropower and the rest of the global energy is 6% of nuclear power, Figure 1. World energy supply 13% 6% 34% Oil Coal 21% Natural gas Renewable energy 26% Nuclear power Figure 1. World energy supply Figure 2. Global primary energy supply

20 Figure 3. Global energy use by sectors In figure 3 it is showed the importance of residential and service sector with 36% of total global energy use. It is a big number that can be reduce using better efficiency an improving buildings for save energy this will reduce impact to the planet of the energy use in residential and service sector. Transport and industry are 28% and 27% respectively, others uses are Global view of Sweden s situation Residential buildings uses a lot of energy for different kind of uses the most important uses is: electricity, warm water and heating/cooling. Unfortunately in the past was not common in residential buildings use it in an efficient way and design the buildings in an efficient energy way. Nowadays our mind is changing and use energy in an efficient way is very important and this efficient is focus too in the residential buildings area. This focus in the efficiency use of the energy is a significant part of the Swedish energy strategy in the Government s bill no. 2008/09:162, A Coordinated Climate and Energy Policy Climate. It is said in this document that Swedish objective for greenhouse gas emission reductions that goes beyond its agreed allocation under the EU Burden Sharing Agreement. Under the terms of the EU allocation, which is legally binding, Sweden s emissions over the period may not exceed 104 % of its emissions in Sweden has gone further and, as its target, has elected that its greenhouse gas emissions shall not exceed 96 % of 1990 emissions (i.e. an actual reduction of 4 % in its emissions), 2

21 achieving this without compensation for uptake in carbon sinks (uptake of greenhouse gases in vegetation and the ground), or by using flexible mechanisms 1. So reduce the amount of energy that is used increasing the efficiency is a green way for reduce greenhouse emission, reduce pollution and act like the fixed way that the strategic document approved by the Government. For know more about the energy consumption of Sweden it is necessary have a look some graphics that describe which the situation of Sweden is Energy consumptions In Figure 4 it is showed the total amount of supply of energy in Sweden in year 2008 in TWh and the different energetic origin of the energy. The total energy supply is 612 TWh. Figure 4. Supply of energy in Sweden 2008 Figure 5 shows the use of energy classifying by sector and the way of supply this energy 1 Swedish Energy Agency, Energy in Sweden

22 Figure 5. Use of energy in Sweden 2008 Figure 5 showed too that the total use of energy is 397 TWh with 151 to Industry, 105 to transport and 141 to Residential and services. The amount of loses are 216 TWh. Figure 6 is a part of figure 2 that shows the same information of the energy use but without classify it per sector. Figure 6. Use of energy in Sweden 2008 It is really useful how we can see the importance of the sector of residential buildings and services, in our case only residential buildings. Telling the importance in numbers 35.5% of the final energy use of all the energy that is really used without counting losses that is a total of 35.2%. It is a big percent that is has to be reduced and is one reason more for study the efficiency and try to reduce these big losses. 4

23 The part of energy use that is more interesting for this project about residential buildings is electricity and district heating energies, being 50.3% and 30.5% respectively and together an amount of 80.8% of total energy used in residential buildings and services. The proportion of renewable energy sources in the country s total energy supply amounted to over 30 % in Renewable energy sources include bio-fuels, hydro power and wind power. It is necessary to save energy in this important amount of energy because saving energy in residential building is an important aspect to avoid polluting of the planet over. Save energy in this area it s the objective of the project. Figure 7 shows the Sweden s total energy use between 1970 and In the part of residential area shows that the consumption is almost the same this fact is relevant because that shows that in the residential buildings nobody take a look for improve the systems for try to save energy and reduce this high consumption that can be reduced. Figure 7. Energy use Figure 8 Total energy uses in Sweden, Conversion losses in the production sector are apportioned to end users. 5

24 Figure 8. Energy use with loses in their sectors Considering all these figures we can determinate that residential buildings is a very important part of the energy consumption and the total consumption of energy suffers big losses. For solve the problem of the high consumption in the area that is relevant for us, the residential buildings, it has to be improved the efficiency and search solutions for try to consume less energy that is spending without needing it all this, improving the systems in residential buildings, reducing loses, or searching new sources of energy that can be used like renewable energy applied to buildings, solar, wind, etc. These solutions will save energy of district heating and electricity too. It was show before in the Figure 5 that almost all the consumption of energy in residential buildings came from this consumption. One thing that it can t be changed with this project is the behavior of the people. It is possible reduce energy with the solutions described before but one of the best solutions is change the behavior of people about use a lot of energy that they don t have to spend and this behavior is caused because energy in Sweden is too cheap. So make people aware to use less electricity, use less warm water, less heating and even less air conditioning and combine this green behavior with technical solutions proposed in this project will be a perfect fit for the Swedish energy strategy. 6

25 1.2.2 Energy use in residential and service sector Energy use in the residential and service sector in Sweden in 2008 is 141 TWh, accounts for 36 % of Sweden s total final energy use. The sector consists of residential buildings, holiday homes and non-residential premises (excluding industrial premises), land use, and other service activities. Of the total energy use in the sector, about 86 % is used in residential buildings and non-residential premises 2. Around 61 % of the energy use in the sector is used for space heating and domestic hot water production. This use of the energy in residential sector is affected by temperature conditions; there can be variations in energy demand from one year to another. Figure 9. Final Energy use in residential Swedish Energy Agency, Energy in Sweden

26 1.2.3 Electricity In figure 10 it is showed that in 2008, total electricity use in Sweden amounted to 144 TWh, residential and service sector is almost half of this energy, and industry is around 39 %. The rest is due to the transport sector, district heating, refineries and distribution losses. Figure 10. Electricity use in Sweden by sectors Lighting is the largest user of domestic electricity, followed by electricity use for refrigerators and freezers in second position, and entertainment electronics (TV, computers etc.) in third position. Per-capita electricity use in Sweden is around kwh per year. The high electricity use in Sweden is due to a high proportion of electricity-intensive industries, a cold climate, a high proportion of electric heating and historically low electricity prices. For know better the importance of the Swedish per-capita electricity use it is necessary take a look to the rest of the world in figure 11. 8

27 Figure 11. Per-capita electricity production by types of production 2008 Figure 11 shows that only Canada, Norway and Iceland have more per capita electricity production and this countries and Sweden have the most hydropower production. It has to be remarked too that Norway and Iceland produce only hydropower. Spain per-capita production is around kwh in District heating District heating is the most used system in Sweden supplying heat for space heating and domestic hot water production for residential buildings commercial premises and industries. It has been used since 1950s. A technical definition of district heating can be: centralized production and supply of hot water, distributed through a piping system and used for the space heating of buildings 3.It is used in the 84.5% of the 290 Sweden s municipalities, so it is clearly the commonest system for heating in apartment buildings, commercial premises and the main form for heating in the city centers. 3 Swedish Energy Agency, Energy in Sweden

28 Combined heat and power, CHP, production is the way for supply the heat in the district heating. CHP power stations supply both, electricity and heat for the hot water distribution. This technology for the district heating grow up quickly since 1970s that it can be seen in the figure 12. Total district heating energy supplied in 2007 was 48 TWh, around 60% for residential heating, apartment buildings and detached houses, 30% for commercial premises and the rest, 10%, is for industry. Figure 12. District heating use The replacement of individual boilers by district heating plants reduces substantially the emissions of sulphur dioxide, soot and nitrogen oxide. It can be seen in the improvement of the air quality in urban areas. A big disadvantage is that district heating system requires an expensive infrastructure and distribution system works as a monopoly. District heating in apartment buildings supply heat to around 82% of the heated floor area while commercial and other premises is 66% heated by it. On the other hand in detached houses only 9% of them use district heating it is due to the expensive infrastructure for build pipes only to this houses that are not in the close to municipality. One important advantage of district heating is the flexibility of what kind of fuel it can be used. In figure 13 shows the evolution in the past years and now around 70% of the energy input comes from bio-fuels. 10

29 Figure 13. Energy input to district heating systems Bio-fuels are significant on district heating. In figure 14 shows the proportion of different bio-fuels in district heating plants. The name of wood fuels includes not densified (logging residues, low quality wood, fire wood, bark, saw dust, dry chips, recycled wood), and densified (pellets, briquettes and powder). Figure 14. Use of bio-fuels in district heating plants * Figures of Swedish Energy Agency, Energy in Sweden

30 1.3 Gavlegårdarna AB Company Gavlegårdarna AB is Gävle s public housing company. Founded in 1917, the company is today one of the oldest and largest in Sweden. The company has around 200 employees and owns apartments with approximately residents and commercial premises. The company builds houses in the municipality of Gävle for sell and rent but the most of them are rented apartment for all different kinds of tenant also for students doing a campus for foreign students from different countries and also from different towns of Sweden. In the case of the buildings studied, also is the case of many buildings that Gavlegårdarna offers, the energy cost is included in the rent, it s mean that if the tenant wastes more energy one month his money rent will not be affected, doesn t matter how much energy is wasted (district heating, warm water and electricity). It is a big reason for try to be more efficient in the energy supply for Gavlegårdarna. Gavlegårdarna is a company part of EURHONET network of European housing companies in both, social and public housing. 12

31 1.4 EURHONET EURHONET is a network of European housing companies in both social and public housing. It is a professional network aiming at: developing European projects of research and development of innovative methods in social and public housing; exchanging ideas and benchmarks between the members; sharing experiences in order to conceive models of best practices; organizing international workshops and seminars related to these issues; reinforcing the debates on social and public housing with public authorities in Europe 4. Figure 15 shows the extension of EURHONET, the countries, companies, etc. Figure 15. EURHONET companies EURHONET has different kinds of projects one of this projects that works Gavlegårdarna and this project was part of it is called retrofitting together project. The retrofitting together project aims to compare the working methods and tools of each EURHONET housing company regarding the rehabilitation process in the context of energy performance. At each step, best practices would be identified and assessed in order to be 13

32 shared among all of the partners. The implication of the knowledge would be tested and evaluated on the pilot site and the result would be the improvement of the energy performance in the retrofitting operation while reducing the cost 4. Retrofitting together project has special requirements for the buildings that can be include for the study. Table 1 shows these requirements that the buildings studied fulfill and objectives like objective energy and cost that EURHONET has like a goal. Table 1. Buildings requirements (*) The results of this project, residential building energy survey and improvement proposal, about the retrofitting together project were presented in the EURHONET meeting in Stockholm, June 2010, by Andres Holmsten, project director of this project in Gavlegårdarna AB. 4 EURHONET Association, (*) Initial Energy Consumption: High Energy Consumption >200 kwh/m² 14

33 1.5 Buildings studied The buildings analyzed in this project, Residential building energy survey and improvement proposal, were built in 1966 with concrete as main material so two of principal objectives of retrofitting together project of EURHONET are fulfilled. They have balconies, a minimum of 3 stores and in the next pages it is showed that they have energy consumption more than 200kWh/m 2 year, this requirement is very important. Figure 16. Building picture, Summer (I) Figure 17. Building picture, Summer (II) 15

34 Figure 18. Building picture, Summer (III) Figure 19. Building picture, Summer (IV) 16

35 Figure 20. Building picture, Winter (I) Figure 21. Building picture, Winter (II) 17

36 1.5.1 Location These buildings are three buildings of the Sweden s municipality of Gävle. They are located in a neighborhood of Sätra. In figures 16, 17 and 18 it is showed the locations of municipality of Gävle, Sätra neighborhood and the buildings. The addresses of the buildings are Glaciärvägen 21, for building number 2, Glaciärvägen 23 for building number 1 and Pinnmovägen 26 for building number 3. Figure 22. Gävle in Sweden 18

37 Figure 23. Sätra in Gävle Figure 24. Buildings in Sätra Plans of the house are in Appendix 7.1 Buildings Plans. They are buildings with ground floor with stores and all four except Glaciärvägen 23 with an apartment in this ground floor too and four residential floors with six apartments per floor of different meter square. 19

38 1.5.2 Areas In the table 2, 3, 4 and 5 it is showed the area of the apartments of the buildings Glaciärvägen 21, Glaciärvägen 23, Pinnmovägen 26 and Pinnmovägen 24. Pinnmovägen 24 is out of the project but is necessary to know information about this for the energy survey. The buildings are quiet similar, Pinnmovägen 26 and Glaciärvägen 23 they have the same plans in residential and ground floor the other two buildings have the same kind of apartments for residential floors. The heated area of the buildings is the residential floors, the apartment in the ground floor and the store also located in the ground floor. 20

39 Pinnmovägen 24 Fastighet I II III IIII m² rk 111, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67,1 m² Area per residential floor Total residential area Store area 216 Total Heated area Table 2. Areas of building Pinnmovägen 24 21

40 Pinnmovägen 26 Fastighet I II III IIII m² rk 112, rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42,7 m² Area per residential floor Total residential area Store area 167 Total Heated Area Table 3. Areas of building Pinnmovägen 26 22

41 Glaciärvägen 21 Fastighet I II III IIII m² rk 111, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67, rk 68, rk 86, rkv 43, rk 98, rk 84, rk 67,1 m² Area per residential floor Total residential area Store area 216 Total Heated Area Table 4. Areas of building Glaciärvägen 21 23

42 Glaciärvägen 23 Fastighet I II III IIII m² rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42, rk 98, rk 84, rk 67, rk 67, rk rkv 42,7 m² Area per residential floor Total residential area Store area 167 Total Heated Area Table 5. Areas of building Glaciärvägen 23 m² Total residential area Total Heated Area Glaciärvägen 21 and Glaciärvägen 23 Pinnmovägen 26 and Pinnmovägen Table 6. Total Areas of group of buildings 24

43 1.5.3 Building Structure The information given by Gavlegårdarna was not completed because buildings are old and they didn t have all the plans due to the age of the buildings they only have a little plan of constructive details and a short report of one page, so a some details had to be supposed by the drawings of the plans and with the short report. The structures of the walls are from outside to inside Foundations In the short report don t give a lot information about the foundation. It s a continuous foundation in all the ground area. The composition has to be supposed of a little constructive detail that is wasn t clear. Gavlegårdarna was ok with this supposition. Continuous Foundation cm Concrete 160 Lightweight concrete 320 Coating < 1 Total 480 U-Value [W/m²K] 0.41 Table 7. Continuous foundation structure External walls Store wall is the external wall in the ground floor that separates interior of store and ambient. In residential floors there are different kinds of external walls, a light concrete wall, a light concrete and wood in the exterior around windows, in pictures of buildings it can see and a curtain wall is the wall behind the windows next to the door balcony they are thin and the main material is insulation. 25

44 Store Wall mm Gypsum 25 Lightweight concrete 350 Gypsum 25 Total 400 U-Value [W/m²K] Table 8. Store wall structure Concrete-Wood Wall mm Wood 20 Light Insulation 45 Lightweight concrete 200 Gypsum 13 Total 278 U-Value [W/m²K] Table 9. Concrete-Wood wall structure Concrete Wall mm Gypsum 25 Lightweight concrete 250 Gypsum 25 Total 300 U-Value [W/m²K] Table 10. Concrete wall structure 26

45 Curtain Wall mm Wood 20 Light Insulation 45 Gypsum 25 Total 78 U-Value [W/m²K] Table 11. Curtain wall structure Windows and doors The windows and door of this section are the windows and doors of residential floors. The doors are the ones that let go to the balconies. The U-Value is according to the short report. Windows and doors are provided with 2-glass. U-Value [W/m²K]: Ceiling to outside It s the ceiling between the apartments and the outside. It was made improvements due to a bad comfort in the apartments. Ceiling to outside mm Asphalt Coated paperboard - Wood 20 Light Insulation 450 Concrete 400 Total 870 U-Value [W/m²K] Table 12. Ceiling to outside structure 27

46 Ceiling to attic store It s the ceiling that is between the apartments and the attic store. The attic store is a place over the fifth floor of residential floors that locate the ventilation room, elevator engine room and other services of the building. Also it can find there some tenant stores like in the stores located in the ground floor. The difference between the stores in the ground floor and the attic stores is the first ones are heated and not the second ones and both are very ventilated, so in the attic stores the temperature is really low in winter. Ceiling to attic store mm Concrete 400 Total 400 U-Value [W/m²K] Table 13. Ceiling to attic store structure Attic store Attic store Walls and Ceiling mm Wood 20 Insulation 100 Wood 20 Total 140 U-Value [W/m²K] 0.32 Table 14. Attic store walls structure 28

47 Attic store Roof mm Asphalt Coated paperboard - Wood 20 Insulation 100 Wood 20 Total 140 U-Value [W/m²K] 0.32 Table 15. Attic store roof structure 29

48 1.5.4 Heated Volume Heat volume is defined as the volume of the building that is heated. In this case are the four floors of residential area and the store in the ground floor. In the project is excluded of the study the residential areas of ground floor or rooms with internal heating like laundry room, because Gavlegårdarna plans to change the distribution or uses, so Gavlegårdarna said that losses to this areas from heated volume as not to be counted. For the retrofitting together project is necessary to show the ratio between external walls and heat volume by this formula: Glaciärvägen 21 External Surface Wall Length [m] Height [m] Area [m²] Residential floors North 20,5 11,0 226,32 East 30,4 11,0 335,62 South 20,5 11,0 226,32 West 30,4 11,0 335,62 Store North 11,4 2,5 28,50 East 25,6 2,5 64,00 South 7,3 2,5 18,25 West 0 2,5 0,00 Roof 448 Total 1683 Table 16. External surface wall Glaciärvägen 21 30

49 Heat Volume Area [m²] Height [m] Volume [m 3 ] Store 216 2,5 540 Residential floors , Total 5023 Table 17. Heat Volume Glaciärvägen 21 Figure 25. Heat Volume ground floor Glaciärvägen 21 31

50 Figure 26. Heat Volume residential floors Glaciärvägen 21 Figure 27. Heat Volume section Glaciärvägen 21 32

51 Glaciärvägen 23 and Pinnmovägen 26 External Surface Wall Length [m] Height [m] Area [m²] Residential floors North 20,5 11,0 226,32 East 30,4 11,0 335,62 South 20,5 11,0 226,32 West 30,4 11,0 335,62 Store North 17,8 2,5 44,50 East 9,5 2,5 23,75 South 0 2,5 0,00 West 16 2,5 40,00 Roof 447 Total 1679 Table 18. External surface wall Glaciärvägen 23 and Pinnmovägen 26 Heat Volume Area [m²] Height [m] Volume [m 3 ] Store 167 2,5 417,5 Residential floors , Total 4891 Table 19. Heat Volume Glaciärvägen 23 and Pinnmovägen 26 33

52 Figure 28. Heat Volume ground floor Glaciärvägen 23 and Pinnmovägen 26 Figure 29. Heat Volume residential floors Glaciärvägen 23 and Pinnmovägen 26 34

53 Figure 30. Heat Volume section Glaciärvägen 23 and Pinnmovägen 26 35

54 1.6 Purpose The aim of the project is to know where it is spent the energy of the buildings studied and find solutions for reduce the energy that the building use for reduce waste of energy, consequence of that is reduce money spend by Gavlegårdarna, and be in concordance with the energy strategy and environmental policy of Sweden making the buildings more efficient showing that the company cares about the environment. In the project apart of the proposal given also gives an approximately economic study of money that has to spend and money save in the different proposal. It s a not exactly economic study it s only approximately study due to difficulty of know how much can cost the proposals studied. The part of ventilation of the buildings is not studied in this project it is studied in other project of the company but the results have to be included in this for be complete the energy survey and the retrofitting together project of EURHONET. 1.7 Limitations Inside the limitations of this project it was the fact that the buildings are quite old and without a good maintenance, it was watched too that some measurements, drawings or information about structure interesting in the project was impossible to take because the pipes net didn t had the instruments or Gavlegårdarna didn t give to us give us late. It was difficult to find companies interested in shows us a budget or a way that can be made the proposal due to the knowledge of be a university project even a well-know company was behind the project. Of course Swedish language was a difficulty to break for understands drawings and information and also a completely different system used in Sweden for climate, ventilate, and offer warm water. 36

55 1.8 Method The method followed in the project was first of all having an agreement with Gavlegårdarna about aims and objectives of the project and about what they wanted. Following this was search information about the buildings, climate, etc. and gets it from the company too. Studying the buildings with the information it can be made a little energy survey about how much it waste the energy during the years 2008 and 2009 and give an approximate amount of money for compare years. It is necessary to know that the waste of energy depends of climatology so it was to be compare to with a normal year, an average year from years past in municipality of Gävle. After it was presented from Gavlegårdarna to me and the responsible of the ventilation project the retrofitting together project from EURHONET, for make it in less time we did together the tests that is necessary to do for the project, ventilation tests and thermal images. It was presented to Gavlegårdarna the proposals and preliminary results for retrofitting together project. Fitting with the ideas given by Gavlegårdarna it was finished the objectives of the company and it was presented for the company a report and a presentation of the results that they need to present this presentation in the EURHONET meeting in Stockholm about retrofitting together project in June For make it the project it was necessary the collaboration of teacher Björn Karlsson, Mathias Chelinn and of course the supervisor of the university Roland Forsberg and supervisor of the company Anders Holmsten. It was used for the project the program IDA Indoor climate and energy 3.0 and Winsun, programs from Högskolan i Gävle. 37

56 2 THEORETICAL FRAMEWORK 2.1 District heating system The district heating system is used for provide thermal energy to the buildings. It s not necessary consume of other kind of energy except electricity that buildings take of the general net of Gävle. A consequence of that is buildings don t have a boiler for burn natural gas, oil, coal or other kinds of primary energy this it is burned in a big central close to the town and other little plants inside the town operated by Gävle Energi AB. This company use like fuel bio-fuel products from wood. They burn it and in big boilers they produce heat to heat water and then have like a product hot water or even steam when it is necessary a big temperature. This heat that water or steam stores flows through big net of pipes for distribute this energy to the town. Pipes are underground as the others urban installations needed. Pipes has to be big and most important has to be with a lot of insulation to avoid looses of circulation of big distances. The net of district heating that provide energy to the buildings is showed in the Appendix 7.2 Sätra District Heating net plan. It can be seen that the net has two inputs for four buildings first input for buildings Pinnmovägen 26 and Pinnmovägen 24 and second input for buildings Glaciärvägen 21 and Glaciärvägen 23. Pinnmovägen 24 is out of the project. This way of distribution makes that Glaciärvägen 23 and Pinnmovägen 26 has a district heating room that there are three heat exchangers. The heat exchangers exchange the energy offered by Gävle Energi through the district heating net. Heat exchangers take the energy for heat water for the grid of radiators of the two buildings and for the warm water for the two buildings too and then give back to the return pipe the energy that is not used. Taking Glaciärvägen 21 and Glaciärvägen 23 has example, in Glaciärvägen 23 is located the district heating room with the heat exchangers then the water heated in the heat exchangers has to flow from the heat exchangers to the all the houses of Glaciärvägen 23 but also to the all the houses of Glaciärvägen 21. So there is a interal grid that connect 38

57 Glaciärvägen 23 and Glaciärvägen 21 by pipes that are underground. Two heat exchangers are used for heating the two buildings and the other heat exchanger is used for provide warm water to the two buildings. The same occur with buildings Pinnmovägen 26 and Pinnmovägen 24; the first one has the district heating room and take the energy from the district heating system and distribute the energy exchanged to the two buildings, but Pinnmovägen 24 is out of the project. It s not possible to know exactly how much energy uses each building because there isn t a meter for measure it. The meter is only located in the district heating room and measure how much is taking from the district heating grid. This was the data provide by Gavlegårdarna. 39

58 2.2 Gävle climate and Degree Days In this section it is showed the normal climate in Gävle and the temperatures in 2008 and 2009 and some months of 2010 for show differences. For understand the climate and compare it internationally it is used the concept of degree day. Degree days are a specialist type of weather data, calculated from readings of outside air temperature. There are three main types of degree days: heating degree days, cooling degree days, and growing degree days. In our case we only use heating degree days. Heating degree days are a measure of how much (in degrees), and for how long (in days), the outside air temperature was below a certain level. They are commonly used in calculations relating to the energy consumption required to heat buildings. 5 This certain level change between winter and summer. Degree days provided by Gavlegårdarna are 17ºC in winter season and 11ºC in summer season. Summer season correspond from half of May until half of September, the rest of the year is winter season. The temperatures 17ºC and 11ºC chosen by Gavlegårdarna are because they assume an internal heating increase of 3ºC from lights, computers, electrical appliances and people in winter and in summer it is added the solar radiation, so with the previous internal heating, solar radiation and windows without blind, only curtains, the internal heating increases is 9ºC. The temperature inside the building it can be assumed as 20ºC in winter season and in summer months it is assumed as 20ºC in months with less average temperature than 11ºC and the months with a more average temperature than 11ºC is the average temperature of the month plus 9ºC. In the following tables are showed the normal temperatures of Gävle, from VVS- Handboken , and degree days from Gavlegårdarna. 5 Web page: 6 Most normal temperatures used in Gävle. Average of thirty years

59 Temperatures Month Normal Average 2008 Average 2009 Average 2010 Average Temp. Temp. Temp. Temp. January -5,1 0, ,9 February -4,9 1,3-5,9-8 March -2,2 0,3-0,8-2 April 3,3 5,1 6,4 4,4 May 8,7 9,6 11,3 June 13,8 14,8 12,5 July 16,6 16,7 16,4 August 15,3 14,2 16 Septembe r 10,7 9,8 12,4 October 5,3 6,8 3,6 November 0,9 0,9 4,4 December -2,1-1 -4,8 Average year 5 6,6 5,8-1,3 Table 20. Temperatures of Gävle, Normal, 2008, 2009 and 2010 until April 20 Temperatures Temperatures Normal Average Temp. Temperatures 2009 Average Temp. Temperatures 2008 Average Temp. Temperatures 2010 Average Temp.* Figure 31. Temperatures of Gävle, Normal, 2008, 2009 and 2010 until April 41

60 Heating Degree Days Month Normal 2008 HDD 2009 HDD 2010 HDD January February March April May June July August September October November December Total Table 21. Heating Degree Days in Gävle in 2008, 2009 and 2010 until April Heating Degree Days per Day Month Normal HDD/Day HDD/Day HDD/Day HDD/Day January 21,2 16,1 20,0 27,9 February 19,3 14,7 20,7 22,6 March 17,7 16,7 17,8 19,0 April 13,6 11,2 9,9 12,2 May 6,1 5,5 3,5 June 1,1 0,2 2,8 July 0,0 0,0 0,0 August 0,4 0,2 0,0 September 6,4 6,5 3,5 October 11,6 10,1 13,4 November 15,8 15,6 12,2 December 20,1 18,0 21,8 Table 22. Heating Degree Days per day in Gävle in 2008, 2009 and 2010 until April 42

61 Heating Degree Days Heating Degree Days Normal Heating Degree Days 2009 HDD Heating Degree Days 2008 HDD Heating Degree Days 2010 HDD* Figure 32. Heating Degree Days of Gävle, Normal, 2008, 2009 and 2010 until April. Heating Degree Days per year 2010 HDD* 2009 HDD 2008 HDD Normal Figure 33. Heating Degree Days of Gävle, per year Normal, 2008, 2009 and 2010 until April. 43

62 Inside Temperature [ºC] Normal January February March April May ,3 June 22,8 23,8 21,5 July 25,6 25,7 25,4 August 24,3 23,2 25 September ,4 October November December Table 23. Inside temperatures inresidential floors of the buildings 2.3 Energy Survey Energy Ratio The energy Ratio is defined as quotient between the consumption of primary energy and the consumption of secondary energy. Definition of primary energy and secondary energy is: Primary energy is the raw fuel that is burned to create heat and electricity, such as natural gas or fuel oil used in onsite generation. Secondary energy is the energy product (heat or electricity) created from a raw fuel, such as electricity purchased from the grid or heat received from a district steam system. 7 The Primary energy used in this building is zero; the building only uses secondary energy, electricity and district heating energy. 7 Web site: ldgs 44

63 2.3.2 Energy Survey: Consumption For calculate the energy survey Gavlegårdarna gave the information about the combined consume of district heating, heating and warm water, of buildings Glaciärvägen 21 and Glaciärvägen 23 and the combined consume of buildings Pinnmovägen 26 and Pinnmovägen 24 also the areas of the apartments and the plans of the buildings. With this information it was calculated the how much energy is waste in the combination of the two different group of buildings, energy per meter square, thanks this an approximation of how much per building, and how much per apartment. For separate the energy for heating and energy of warm water it was necessary transform the demand volume of warm water in energy. The demand volume was information given from Gavlegårdarna. The volume was transformed thanks to the equation: q = m C p ΔT (eq.1) q is Heat (in MWh or kwh), m is mass, C p is Specific heat and ΔT is Difference of temperature. With the equation and this input it can be calculated: Kcal = 4,186 KJ d water [Kg/m3] = 1000 (density) C p,water [Kcal/KgºC] = 1 ΔT warm water [ºC] = 50 The difference of temperature of 50ºC is because the water has to be heated from 10ºC, taken of the water grid of Gävle from 60ºC for provide healthy warm water without bacteria. Now it is known how much energy equals the volume of water supplied. For now the energy waste in heating is the difference between the total heat taken of the district heating minus the energy of the warm water. 45

64 2.3.3 Energy Survey: Losses U-Values U-Values were calculated thanks program IDA Climate and Energy 3.0 from Högskolan i Gävle with license ICE30:10JUL W6C457 to Ricardo Moya Jaraba except windows U-Value that was an information given in the structure short report. IDA software calculate U-values with the information of which part of the structure and with the design of the structure, materials and thickness. Thanks this information and the internal formula of equation 2 IDA calculate the U-value to the user. (eq. 2) Calculation For calculate the losses from the different parts of the building it was necessary calculate how much area from the different parts of the structure because each part has a different U-Value. With this input and the following formula it can be calculated the energy transferred by the different structural parts. E = U A ΔT Time (eq. 3) E is energy in MWh or kwh, U is U-Value in W/m 2 ºC, Time is in hours and ΔT is the difference of temperatures from inside to outside in ºC. 46

65 Thanks to the concept of degree days that include the product of ΔT Time the equation can be written like this. E = U A DegreeDays (eq. 4) The only change for have the same result is multiply degree days per twenty four, the number of hours per day, due to the unit of time in degree days are days and with this little change the energy it will be expressed like, MWh or kwh, the most commons units for energy Foundation Foundation has a particularly way of calculation because the distance of one meter from outside to inside is calculated like the heat is transfer to outside; it means to outside temperature and the interior part of the foundation since this limit of one meter is transferred to the ground. The ground temperature is 5ºC provide by supervisor Roland Forsberg, SWECO AB Company. The area transferred to outside it will be calculated with equation 4 and the area that is transferred to ground it is calculated with equation 3, T inside for winter season of 17ºC because in the store there aren t people living, electric appliances, etc, T inside of 11ºC for summer season and T outside of 5ºC, for Time term it will be the hours for winter season and summer season the sum of the two season it is the total losses to the ground in a year. Figure 34. Foundation losses 47

66 External Walls External Walls are calculated with equation 4 and with the information that the three buildings have the same facade in the same orientations, north, south, east and west in the residential floors only in ground floor is different. So the three buildings have the same losses in the residential floors looking the external walls Windows and doors Windows and doors looses are calculated in the same way like external walls with equation 4. The different areas of the windows and doors balconies are showed in the next table. Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Ground floor Length [m] Height [m] Area [m²] Number Windows 0,6 0,78 0,5 1 Floor 1 & 2 & 3 & 4 Length [m] Height [m] Area [m²] Number per floor Total Area per floor [m²] Total Area [m²] 1,23 1,13 1, ,4 5,6 1,33 1,43 1, ,8 15,2 Windows 1,83 1,43 2, ,9 83,7 2,23 1,43 3, ,7 114,8 3,13 1,43 4, ,0 35,8 Doors 0,9 2,28 2, ,3 49,2 Total Area per building [m²] 304,8 Table 24. Windows and doors areas per building 48

67 Ceiling to outside Ceiling to outside looses are calculated in the same way like external walls and windows and doors looses, with the equation 4. Figure 35. Ceiling losses Ceiling to attic store For calculate the losses from ceiling to attic store and the temperature in the no-climate attic store but ventilated it was necessary the information of how much ventilation has the attic store. This information is 180 l/s or 0.18 m 3 /s. The balance is, the heat transferred from fifth floor apartments to attic store (Q) equal to attic walls and ceiling transmission (Q ) and ventilation losses (Q v ). Thanks this information and the following formula the temperature in the attic store it can be calculated. Q = Q + Q v (eq. 5) Q v = ṁ C v, air (T attic -T out ) (eq. 6) Q = U ceiling to attic A (T in -T attic ) (eq. 7) Q = U attic walls and roof A (T attic -T out ) (eq. 8) In equation 5 the unknown factor is T attic or attic temperature and with the information of U-Values, the areas of transmission and C v, air =1293 [J/ºCm 3 ] it can be calculated. 49

68 With the value of T attic known the losses from fifth floor to attic store can be calculated with equation 3. ΔT it s between T inside and T attic and for Time term is the total hours of the months Thermal photography Thermal pictures was token for retrofitting together project for show the windows leaks, and good or bad state of other windows and doors. The leaks where located in most of the cases in the corners. In the picture (I) it can be seen the big leaks of one window the date is 17 th of March of 2010 at 20:13h, this information can be seen in the picture also the temperature of the infiltration, -2ºC, when outside temperature was around -4ºC. Other window with big leaks is showed in picture (II) Thermal photography was used to show the leaks in the construction and the different temperatures in the materials, pictures (III) and (IV). Leaks in the main door of the building are showed in picture (V). At the end in picture (VI) is showed a good window without leaks only the regular window gap for ventilation and the radiator and picture (VII) it is showed Ricardo Moya Jaraba at 36ºC, healthy and without fever, pointing a window gap. Figure 36. Thermal picture (I) 50

69 Figure 37. Thermal picture (II) Figure 38. Thermal picture (III) 51

70 Figure 39. Thermal picture (IV) Figure 40. Thermal picture (V) 52

71 Figure 41. Thermal picture (VI) Figure 42. Thermal picture (VII) 53

72 2.4 Windows and doors improvement For calculate how much improvement it has the proposal it is calculated the new losses with the new windows and doors in the same way like the old ones. After this calculation of the new losses, the difference between the old losses and the new ones is the improvement savings. 2.5 Ceiling to attic improvement Ceiling to attic improvement has the same calculation method as windows and doors improvement. 2.6 Solar Energy proposal For calculate the solar energy it was used the software WinSun given by teacher Björn Karlsson, WinSun based on TRNSYS/TRNSED/PRESIM 14.2 Bengt Peres and Björn Karlsson EBD_LTH With the software it was studied which tilt can get the most energy in a year in the situation of Gävle, but the problem is that WinSun don t have the weather dates of Gävle so for simulate this it was done an approximation between Stockholm and Gävle because the software can calculate it for Stockholm. Thanks to the information obtained in WinSun, kwh/m² and per month, and the distribution design of solar collectors, total area, it can be calculated how much energy can take from solar collectors by month. The distribution of the solar collectors was calculated with a shadow of collectors of 20º in horizontal surface, due to the surface of the top of the building is almost horizontal this little tilt is not so important. 54

73 2.7 Investment study The investment study is calculated with two common information methods, the Net Present Value (NPV) and Payback. The investment of the proposal was searched in different Swedish companies, for windows and doors is the company Elitefönster AB, for the improvement of ceiling to attic store it is Skanska AB, and for the Solar Collectors it s an information given by Björn Klarsson thanks to his contacts in the Solar Energy in Sweden. For do it more complete the it is study with an increase of the energy of 2%, 4% and 6%, because it is supposed that the energy cost will increase this 30 years Net Present Value It is calculated with an interest rate of 6% and a invest duration of 30 years, because it is a common information in building construction. The formula for Net Present Value including the increase of energy cost is: I is the investment of the proposal. R is the recovery of the investment and the formula for recovery is: 55

74 E is the Energy saved in a year of the proposal, and C is the cost of district heating energy provided by Gavlegårdarna, 0.43 SEK/kWh, and factor (1+i e ) n for the increase of the cost of energy, with the rate i e, the cost of energy increase in the study 2%, 4% and 6%, n is the numbers of years. The rate i is the interest rate of 6% constant in the 30 years. If the NPV is more than 0 it is a good investment and money is earned if it is less than 0 is a bad inversion and money is wasted. NPV don t say information about when the investment start to be profitable for this it is used Payback Payback It says when the investment starts to be profitable and the way for calculate it is sum the factors of NTV year by year and see when the result change from a less than zero result to more than zero result. These tables with the result year by year of the paybacks proposals are in the Appendix X. 56

75 3 PROCESS and RESULTS In this section it is showed the process and the results of the energy survey and also the different proposal studied with an approximation in the economic aspect of the different proposal. The proposals are change of old windows, study of infiltration in the fifth floor and an amount of energy can be used with solar collectors. 3.1 Energy Survey: Consumption Summary information Energy survey of the buildings shows thanks to the tables how the buildings waste the energy in the years 2008 and It was calculated by the information obtained by Gavlegårdarna. The consume of warm water and the consume of space heating has to be separated in the way mentioned in the theoretical framework, as it has to be separated the consume of the buildings because the data was consume of Glaciärvägen 21 and Glaciärvägen 23 and the consume of Pinnmovägen 26 and Pinnmovägen 24, as it is mentioned in the theoretical framework the way for calculate the energy survey. The all tables of the energy survey is in Appendix 7.3 Energy Consumption, here it is showed the most important information and figures District heating [MWh] Glaciärvägen 21 & 23 Pinnmovägen 24 & 26 Glaciärvägen 21 & 23 Pinnmovägen 24 & 26 General Heating Warm Water Warm Water [m 3 ] Table 25. District heating energy consumption in of the two groups of buildings in 2009 and

76 [MWh] 2009 Glaciärvägen 21 Glaciärvägen 23 Pinnmovägen 26 Pinnmovägen 24 General Heating Warm Water Table 26. District heating energy consumption of each buildings in 2009 [MWh] 2008 Glaciärvägen 21 Glaciärvägen 23 Pinnmovägen 26 Pinnmovägen 24 General Heating Warm Water Table 27. District heating energy consumption of each buildings in 2008 [kwh]/[m2] Glaciärvägen 21 & 23 Pinnmovägen 24 & 26 Glaciärvägen 21 & 23 Pinnmovägen 24 & 26 General Heating Warm Water Table 28. District heating energy consumption in of the two groups of buildings per m² in 2009 and

77 January February March April May June July August September October November December January February March April May June July August September October November December Ricardo Moya Jaraba 120 [MWh] District heating Pinnmovägen 24 & 26; 2009 Pinnmovägen 24 & 26; 2008 Figure 43. Energy used of General district heating in Pinnmovägen group of buildings in years 2009 and [MWh] District heating Glaciärvägen 21 & 23; 2009 Glaciärvägen 21 & 23; 2008 Figure 44. Energy used of General district heating in Glaciärvägen group of buildings in years 2009 and

78 January February March April May June July August September October November December January February March April May June July August September October November December Ricardo Moya Jaraba 120,00 100,00 80,00 60,00 40,00 20,00 0,00 [MWh] Heating Pinnmovägen 24 & 26; 2009 Pinnmovägen 24 & 26; 2008 Figure 45. Energy used in heating in Pinnmovägen group of buildings in years 2009 and ,00 120,00 100,00 80,00 60,00 40,00 20,00 0,00 [MWh] Heating Glaciärvägen 21 & 23; 2009 Glaciärvägen 21 & Figure 46. Energy used in heating in Glaciärvägen group of buildings in years 2009 and

79 January February March April May June July August September October November December January February March April May June July August September October November December Ricardo Moya Jaraba 18,00 16,00 14,00 12,00 10,00 8,00 6,00 4,00 2,00 0,00 [MWh] Warm Water Pinnmovägen 24 & 26; 2009 Pinnmovägen 24 & 26; 2008 Figure 47. Energy used in warm water in Pinnmovägen group of buildings in years 2009 and ,00 25,00 20,00 15,00 10,00 5,00 0,00 [MWh] Warm Water Glaciärvägen 21 & 23; 2009 Glaciärvägen 21 & Figure 48. Energy used in warm water in Glaciärvägen group of buildings in years 2009 and

80 Electricity [MWh] Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Table 29. Electricity consumption in 2009 and 2008 [kwh/m²] Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Table 30. Electricity consumption per meter square in 2009 and Total Energy 2009 Energy [MWh] [kwh/m²] Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Total - - Total Buildings studied Table 31. Total Energy use for buildings in

81 2008 Energy [MWh] [kwh/m²] Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Total - - Total Buildings studied - - Table 32. Total Energy use for buildings in Cost The price of the money between SEK and Euro in this period of time changes between 9.5 and 10.5, in this project the change it is stabilized in 10. So 1 Euro equals 10 SEK District heating The cost of the district heating, information given by Gavlegårdarna, it is 0.43 SEK/kWh. General information about the district heating s cost in the buildings is showed in the next tables Energy Cost [MWh] SEK Glaciärvägen 21 & , ,6 Pinnmovägen 24 & , ,4 Glaciärvägen , , ,8 Glaciärvägen , , ,8 Pinnmovägen , , ,0 Pinnmovägen , , ,4 Total 1705, , ,0 Total Buildings studied 1361, , ,0 Table 33. Summary cost of district heating in

82 2008 Energy Cost [MWh] SEK Glaciärvägen 21 & , , ,7 Pinnmovägen 24 & , , ,9 Glaciärvägen , , ,7 Glaciärvägen , , ,0 Pinnmovägen , , ,1 Pinnmovägen , , ,8 Total 1780, , , Electricity Total Buildings studied 1414, , ,5 Table 34. Summary cost of district heating in 2008 The cost of electricity, information given by Gavlegårdarna, it is 1.3 SEK/kWh. So general information about the district heating s cost in the buildings are showed in the next table Energy Cost [MWh] SEK Glaciärvägen 21 30, , ,0 Glaciärvägen 23 37, , ,0 Pinnmovägen 26 20, , ,0 Pinnmovägen Total Total Buildings studied 88, , ,0 Table 35. Summary cost of electricity in

83 2008 Energy Cost [MWh] SEK Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Total Total Buildings studied Table 36. Summary cost of electricity in Total Cost 2009 Cost SEK Glaciärvägen , ,8 Glaciärvägen , ,8 Pinnmovägen , ,4 Pinnmovägen Total - - Total Buildings studied Table 37. Total cost of Building in Cost SEK Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Total - - Total Buildings studied - - Table 38. Total cost of Building in

84 3.2 Energy Survey: Losses Foundation Glaciärvägen 21 Ground losses Months Energy [MWh] January 0,63 February 0,57 March 0,63 April 0,61 May 0,47 June 0,31 July 0,32 August 0,32 September 0,31 October 0,47 November 0,61 December 0,63 Total Energy [MWh] 5,87 66

85 Perimeter Ground losses Area 43,6 m² Energy [kwh] U A Normal January 17,9 281,4 214,5 266,0 February 17,9 256,6 195,2 275,9 March 17,9 235,5 222,2 237,3 April 17,9 180,6 148,9 131,3 May 17,9 81,5 73,4 46,3 June 17,9 15,0 3,0 36,9 July 17,9 0,0 0,0 0,0 August 17,9 5,1 3,0 0,0 September 17,9 84,9 86,2 45,9 October 17,9 154,9 134,3 178,5 November 17,9 209,8 207,2 162,2 December 17,9 266,9 239,0 290,4 Energy [MWh/year] 1,8 1,5 1,7 Total Energy Glaciärvägen 21 [MWh/year] 7,6 7,4 7,5 Table 39. Foundation losses in Glaciärvägen 21 for normal year, 2008 and 2009 Glaciärvägen 23 or Pinnmovägen 26 Ground losses Months Energy [MWh] January 0,46 February 0,42 March 0,46 April 0,45 May 0,35 June 0,22 July 0,23 August 0,23 September 0,22 October 0,35 November 0,45 December 0,46 Total Energy [MWh/year] 4,31 67

86 Perimeter Ground losses Area 40,6 m² Energy [kwh] Month U A Normal January 16,6 262,1 199,8 247,7 February 16,6 238,9 181,8 256,9 March 16,6 219,3 206,9 220,9 April 16,6 168,2 138,6 122,2 May 16,6 75,9 68,3 43,1 June 16,6 14,0 2,8 34,4 July 16,6 0,0 0,0 0,0 August 16,6 4,8 2,8 0,0 September 16,6 79,1 80,3 42,7 October 16,6 144,2 125,0 166,2 November 16,6 195,4 193,0 151,0 December 16,6 248,5 222,5 270,5 Energy [MWh/year] 1,7 1,4 1,6 Total Energy Glaciärvägen 23 or Pinnmovägen 26 [MWh/year] 6,0 5,7 5,9 Table 40. Foundation losses in Glaciärvägen 23 or Pinnmovägen 26 for normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 19,6 18,8 19,3 Table 41. Foundation losses in the three buildings for normal year, 2008 and

87 3.2.2 External walls Store Wall Glaciärvägen 21 Area 120 m² Energy [kwh] Month U A Normal January 43,9 691,9 527,3 653,9 February 43,9 630,7 479,9 678,1 March 43,9 579,0 546,3 583,2 April 43,9 444,0 366,0 322,7 May 43,9 200,4 180,3 113,9 June 43,9 36,9 7,4 90,7 July 43,9 0,0 0,0 0,0 August 43,9 12,7 7,4 0,0 September 43,9 208,8 212,0 112,8 October 43,9 380,7 330,1 438,7 November 43,9 515,7 509,4 398,7 December 43,9 656,0 587,4 714,0 Total Energy Glaciärvägen 21 [MWh/year] 4,4 3,8 4,1 Table 42. Store Wall losses in Glaciärvägen 21 in Normal year, 2008 and

88 Glaciärvägen 23 or Pinnmovägen 26 Area 110,25 m² Energy [kwh] Month U A Normal January 40,4 635,6 484,5 600,8 February 40,4 579,4 440,9 623,0 March 40,4 532,0 501,9 535,8 April 40,4 407,9 336,2 296,5 May 40,4 184,1 165,7 104,6 June 40,4 33,9 6,8 83,3 July 40,4 0,0 0,0 0,0 August 40,4 11,6 6,8 0,0 September 40,4 191,9 194,8 103,7 October 40,4 349,8 303,3 403,1 November 40,4 473,8 468,0 366,3 December 40,4 602,7 539,7 656,0 Total Energy Glaciärvägen 23 or Pinnmovägen 26 [MWh/year] 4,0 3,4 3,8 Table 43. Store Wall losses in Glaciärvägen 23 and Pinnmovägen 26 in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 12,4 10,7 11,7 Table 44. Store Wall losses in the three building in Normal year, 2008 and

89 Concrete Wall Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Area 843,9 m² Energy [MWh] Month U A Normal January 408,9 6,4 4,9 6,1 February 408,9 5,9 4,5 6,3 March 408,9 5,4 5,1 5,4 April 408,9 4,1 3,4 3,0 May 408,9 1,9 1,7 1,1 June 408,9 0,3 0,1 0,8 July 408,9 0,0 0,0 0,0 August 408,9 0,1 0,1 0,0 September 408,9 1,9 2,0 1,0 October 408,9 3,5 3,1 4,1 November 408,9 4,8 4,7 3,7 December 408,9 6,1 5,5 6,6 Total Energy per building [MWh/year] 40,5 34,9 38,2 Table 45. Concrete wall losses per building in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 121,6 104,8 114,6 Table 46. Concrete wall losses in the three buildings in Normal year, 2008 and

90 Concrete-Wood Wall Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Area 62,1 m² Energy [kwh] Month U A Normal January 21,0 330,7 252,0 312,5 February 21,0 301,4 229,3 324,1 March 21,0 276,7 261,1 278,7 April 21,0 212,2 174,9 154,2 May 21,0 95,8 86,2 54,4 June 21,0 17,6 3,5 43,3 July 21,0 0,0 0,0 0,0 August 21,0 6,0 3,5 0,0 September 21,0 99,8 101,3 53,9 October 21,0 182,0 157,8 209,7 November 21,0 246,5 243,5 190,5 December 21,0 313,5 280,8 341,2 Total Energy per building [MWh/year] 2,1 1,8 2,0 Table 47. Concrete-wood wall losses per building in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 6,2 5,4 5,9 Table 48. Concrete wall losses in the three buildings in Normal year, 2008 and

91 Curtain Wall Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Area 46,3 m² Energy [kwh] Month U A Normal January 28,6 449,6 342,7 424,9 February 28,6 409,8 311,8 440,7 March 28,6 376,3 355,0 379,0 April 28,6 288,5 237,8 209,7 May 28,6 130,2 117,2 74,0 June 28,6 24,0 4,8 58,9 July 28,6 0,0 0,0 0,0 August 28,6 8,2 4,8 0,0 September 28,6 135,7 137,8 73,3 October 28,6 247,4 214,5 285,1 November 28,6 335,1 331,0 259,1 December 28,6 426,3 381,7 464,0 Total Energy per building [MWh/year] 2,8 2,4 2,7 Table 49. Curtain wall losses per building in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 8,5 7,3 8,0 Table 50. Concrete wall losses in the three buildings in Normal year, 2008 and

92 Summary total losses of external walls Glaciärvägen 21 Energy [MWh] Month Normal January 7,91 6,03 7,48 February 7,21 5,49 7,75 March 6,62 6,25 6,67 April 5,08 4,18 3,69 May 2,29 2,06 1,30 June 0,42 0,08 1,04 July 0,00 0,00 0,00 August 0,14 0,08 0,00 September 2,39 2,42 1,29 October 4,35 3,77 5,02 November 5,90 5,82 4,56 December 7,50 6,72 8,16 Total Energy External Walls Glaciärvägen 21 [MWh] 49,8 42,9 46,9 Table 51. Summary Total Energy losses External Walls losses in Glaciärvägen 21 in Normal year, 2008 and

93 Glaciärvägen 23 or Pinnmovägen 26 Energy [MWh] Month Normal January 7,85 5,99 7,42 February 7,16 5,45 7,70 March 6,57 6,20 6,62 April 5,04 4,15 3,66 May 2,27 2,05 1,29 June 0,42 0,08 1,03 July 0,00 0,00 0,00 August 0,14 0,08 0,00 September 2,37 2,41 1,28 October 4,32 3,75 4,98 November 5,85 5,78 4,53 December 7,45 6,67 8,10 Total Energy External Walls Glaciärvägen 23 or Pinnmovägen 26 [MWh] 49,5 42,6 46,6 Table 52. Summary Total Energy losses External Walls losses in Glaciärvägen 23 and Pinnmovägen 26 in Normal year, 2008 and 2009 Summary Total Energy External Walls Energy [MWh/year] Normal Glaciärvägen 21 49,8 42,9 46,9 Glaciärvägen 23 or Pinnmovägen 26 49,5 42,6 46,6 Total Energy in the three buildings 148,7 128,1 140,2 Table 53. Summary Total Energy losses External Walls losses in the three buildings in Normal year, 2008 and

94 3.2.3 Windows and doors Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Area 304,8 m² Energy [MWh] Month U A Normal January 823,1 13,0 9,9 12,2 February 823,1 11,8 9,0 12,7 March 823,1 10,8 10,2 10,9 April 823,1 8,3 6,9 6,0 May 823,1 3,8 3,4 2,1 June 823,1 0,7 0,1 1,7 July 823,1 0,0 0,0 0,0 August 823,1 0,2 0,1 0,0 September 823,1 3,9 4,0 2,1 October 823,1 7,1 6,2 8,2 November 823,1 9,7 9,5 7,5 December 823,1 12,3 11,0 13,4 Total Energy per building [MWh/year] 81,6 70,3 76,9 Table 54. Windows and doors looses per building in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 244,8 210,9 230,8 Table 55. Windows and doors looses in the three buildings in Normal year, 2008 and

95 3.2.4 Ceiling to outside Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Area 329,7 m² Energy [kwh] Month U A Normal January 25,7 404,8 308,6 382,6 February 25,7 369,0 280,8 396,8 March 25,7 338,8 319,7 341,3 April 25,7 259,8 214,1 188,8 May 25,7 117,3 105,5 66,6 June 25,7 21,6 4,3 53,1 July 25,7 0,0 0,0 0,0 August 25,7 7,4 4,3 0,0 September 25,7 122,2 124,0 66,0 October 25,7 222,8 193,2 256,7 November 25,7 301,8 298,1 233,3 December 25,7 383,9 343,7 417,8 Total Energy per building [MWh/year] 2,5 2,2 2,4 Table 56. Ceiling to outside looses per building in Normal year, 2008 and 2009 Energy [MWh/year] Normal Total Energy in the three buildings 7,6 6,6 7,2 Table 57. Ceiling to outside looses in the three buildings in Normal year, 2008 and

96 3.2.5 Ceiling to attic store Attic Temperature [ºC] Area ceiling to attic 118,6 m² Area attic walls and roof 267,5 m² Normal January February March April May June July August September October November December Table 58. Attic temperature in Normal year, 2008 and 2009 Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 ΔT [ºC] Energy [MWh] Month U A Normal Normal January 290,8 13,1 10,0 12,0 2,8 2,2 2,6 February 290,8 13,0 9,8 13,5 2,8 2,1 2,9 March 290,8 11,6 10,3 10,9 2,5 2,2 2,4 April 290,8 8,7 7,8 7,1 1,9 1,7 1,5 May 290,8 5,9 5,4 4,7 1,3 1,2 1,0 June 290,8 4,7 4,7 4,7 1,0 1,0 1,0 July 290,8 4,7 4,7 4,7 1,0 1,0 1,0 August 290,8 4,7 4,7 4,7 1,0 1,0 1,0 September 290,8 4,9 5,3 4,7 1,1 1,2 1,0 October 290,8 7,7 6,9 8,6 1,7 1,5 1,9 November 290,8 10,0 10,0 8,2 2,2 2,2 1,8 December 290,8 11,5 11,0 13,0 2,5 2,4 2,8 Total Energy per building [MWh/year] 21,8 19,6 20,9 Table 59. Ceiling to attic store looses per building in Normal year, 2008 and

97 Energy [MWh/year] Normal Total Energy in the three buildings 65,3 58,8 62,8 Table 60. Ceiling to attic store looses in the three buildings in Normal year, 2008 and Summary Total looses Conduction losses Energy [MWh/year] Normal Glaciärvägen ,4 142,4 154,7 Glaciärvägen 23 or Pinnmovägen ,3 140,4 152,7 Total Energy in the three buildings [MWh] 486,0 423,3 460,2 Table 61. Conduction losses in the three buildings in Normal year, 2008 and Ventilation losses Ventilation losses Energy 2009 [MWh] Glaciärvägen 21 Glaciärvägen 23 Pinnmovägen 26 January 29,8 29,9 30,5 February 30,1 30,2 30,8 March 28,2 28,3 15,6 April 23,7 23,9 12,8 May 17,8 18,0 9,1 June 9,3 9,4 3,5 July 2,8 2,8 0,0 August 4,6 4,6 0,5 September 9,8 9,9 3,9 October 19,9 20,1 10,4 November 19,3 19,5 20,3 December 28,5 28,6 29,3 Total [MWh] 224,0 225,2 233,4 Table 62. Ventilation losses in the three buildings in

98 Total losses 2009 Energy [MWh] Glaciärvägen 21 Glaciärvägen 23 Pinnmovägen 26 January 53,40 53,24 53,84 February 54,73 54,59 55,19 March 49,38 49,27 36,52 April 35,90 35,86 24,82 May 22,87 22,89 13,99 June 13,42 13,42 7,59 July 4,16 4,10 1,25 August 5,93 5,88 1,73 September 14,65 14,65 8,66 October 35,94 35,92 26,27 November 34,11 34,04 34,87 December 54,22 54,08 54,74 Total [MWh] 378,71 377,95 319,46 Table 63. Total losses in the three buildings in year

99 3.3 Windows proposal Summary information Widows buildings are the same windows since 1966, when the building was built, only a few ones has a little repair but still the same ones. Windows has a little gap in the top and its function is for ventilation and provides fresh air from outside. The gap is showed in the next figure. Figure 49. Windows ventilation gap The areas of the windows are showed in the table 23 in section Windows and doors, page 48. The U-Value of the windows and doors building s is defined in section Windows and doors page 27. The improvement for the windows is changing it for others with better U-value. In the market there is a lot of kind of windows with several U-values and the actual U-value is the worst U-Value offered in the market. The proposal is change the actual windows and doors in the residential floors and the little window in the store of ground floor to Elit fönster tradition 2+1 glass from company ELITFÖNSTER. This type of windows with open to inside, the same type like the actual ones, have a U-Value of 1.1 [W/m 2 ºC]. The range tradition 2+1 glass has a model for balconies doors with the same U-Value. 81

100 3.3.2 Energy report Energy looses Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 U-Value 1,1 W/m 2 ºC Area 304,8 m² Energy [MWh] Month U A Normal January 335,3 5,3 4,0 5,0 February 335,3 4,8 3,7 5,2 March 335,3 4,4 4,2 4,5 April 335,3 3,4 2,8 2,5 May 335,3 1,5 1,4 0,9 June 335,3 0,3 0,1 0,7 July 335,3 0,0 0,0 0,0 August 335,3 0,1 0,1 0,0 September 335,3 1,6 1,6 0,9 October 335,3 2,9 2,5 3,3 November 335,3 3,9 3,9 3,0 December 335,3 5,0 4,5 5,4 Total Energy per building [MWh/year] 33,2 28,6 31,3 Total Energy in 99,7 85,9 94,0 the three buildings [MWh/year] Table 64. Energy losses with new windows and doors in Normal year, 2008 and

101 Energy Savings Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 U-Value 1,1 W/m 2 ºC Area 304,8 m² Savings [MWh] Month Normal January 7,7 5,9 7,3 February 7,0 5,3 7,5 March 6,4 6,1 6,5 April 4,9 4,1 3,6 May 2,2 2,0 1,3 June 0,4 0,1 1,0 July 0,0 0,0 0,0 August 0,1 0,1 0,0 September 2,3 2,4 1,3 October 4,2 3,7 4,9 November 5,7 5,7 4,4 December 7,3 6,5 7,9 Energy Savings per building [MWh/year] 48,4 41,7 45,6 Energy Savings in the three buildings [MWh/year] 145,1 125,0 136,7 Energy Savings 59,3% Table 65. Energy savings with new windows and doors in Normal year, 2008 and

102 3.3.3 Economic report Savings in energy cost Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Saving cost SEK Month Normal Normal January February March April May June July August September October November December Total Saving cost per building Total saving cost in the three buildings Table 66. Saving in energy cost with new windows and doors in Normal year, 2008 and

103 Investment study Glaciärvägen 21, Glaciärvägen 23 and Pinnmovägen 26 Cost of energy 0,43 SEK/kWh Investment SEK Duration Investment 30 Years Recovery yearly SEK Energy Savings 145,1 MWh Money savings SEK/year Table 67. Investment Information in Windows and doors proposal NPV [SEK] 2,00% 4,00% 6,00% Payback [years] 2,00% 4,00% 6,00% Table 68. NPV and Payback of the Investment of Windows and doors proposal 85

104 3.4 Ceiling to attic store proposal Summary information Fifth floor ceiling has two different ceiling because it was reformed and improved cause of a lot of losses. It was only reformed the ceiling to outside but the ceiling to the attic store which is not heated. So the heat is transferred to attic store and heat in the fifth floor heat the attic store, all this heat is wasted, because it s not planed a heated attic store. For make a comfortable space not only for people who has to keep their stuff and maintenance building stuff I have set a design of new attic temperature no less than 0ºC in a Normal year. Thanks this limit of temperature and the structure information about the ceiling in section ceiling to attic store, in page 28, it was designed a new floor only in this area. The ceiling to attic store thinness it will increase only in this area and in the attic store side. The thinness increase is in attic side for facilitate the construction and because SWECO knows solution of build this floor because people has to walk there and stuffs it will be kept so it requires resistance. The new ceiling to attic store or the new floor for in the attic store only increase in seven centimeters the new design is showed in the following table. Ceiling to attic store mm Normal Concrete 400 Light insulation 30 Wood 20 Floor coating 20 U-Value [W/m 2 ºC] 0,67 Table 69. Ceiling to attic store proposal 86

105 3.4.2 Energy report Energy losses Attic Temperature U-Value 0,67 W/m 2 ºC Area ceiling to attic 118,6 m² Area attic walls and roof 267,5 m² Normal January February March April May June July August September October November December Table 70. Attic temperature with the ceiling improvement in Normal year, 2008 and

106 Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 U-Value 0,67 W/m 2 ºC Area 118,6 m² ΔT Energy [MWh] Month U A Normal Normal January 79,5 20,1 15,3 18,4 1,2 0,9 1,1 February 79,5 19,9 15,0 20,7 1,2 0,9 1,2 March 79,5 17,8 15,8 16,6 1,1 0,9 1,0 April 79,5 13,4 11,9 10,9 0,8 0,7 0,6 May 79,5 9,0 8,3 7,2 0,5 0,5 0,4 June 79,5 7,2 7,2 7,2 0,4 0,4 0,4 July 79,5 7,2 7,2 7,2 0,4 0,4 0,4 August 79,5 7,2 7,2 7,2 0,4 0,4 0,4 September 79,5 7,4 8,2 7,2 0,4 0,5 0,4 October 79,5 11,8 10,6 13,1 0,7 0,6 0,8 November 79,5 15,3 15,3 12,5 0,9 0,9 0,7 December 79,5 17,7 16,8 19,8 1,0 1,0 1,2 Total Energy per building [MWh/year] 9,1 8,2 8,8 Total Energy in 27,3 24,6 26,3 the three buildings [MWh/year] Table 71. Energy losses ceiling to attic store with new ceiling in Normal year, 2008 and

107 Energy savings Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 U-Value 0,67 W/m 2 ºC Area 118,6 m² Energy [MWh] Month Normal January 1,7 1,3 1,5 February 1,6 1,2 1,7 March 1,5 1,3 1,4 April 1,1 1,0 0,9 May 0,7 0,7 0,6 June 0,6 0,6 0,6 July 0,6 0,6 0,6 August 0,6 0,6 0,6 September 0,6 0,7 0,6 October 1,0 0,9 1,1 November 1,3 1,3 1,0 December 1,5 1,4 1,6 Energy Saving per building [MWh/year] Energy Savings in the three buildings [MWh/year] 12,6 11,4 12,2 37,9 34,2 36,5 Energy Savings 58,15% Table 72. Energy savings with new ceiling to attic store in Normal year, 2008 and

108 3.4.3 Economic report Savings in energy cost Glaciärvägen 21 or Glaciärvägen 23 or Pinnmovägen 26 Saving cost SEK Month Normal Normal January February March April May June July August September October November December Total Saving cost per building Total saving cost in the three buildings Table 73. Saving in energy cost with new ceiling to attic store in Normal year, 2008 and

109 Investment study Glaciärvägen 21, Glaciärvägen 23 and Pinnmovägen 26 Cost of energy 0,43 SEK/kWh Investment SEK Duration Investment 30 Years Recovery yearly SEK Energy Savings 27,3 MWh Money savings SEK/year Table 74. Investment Information in Ceiling to attic store proposal NPV [SEK] Payback [years] 2,00% 4,00% 6,00% 2,00% 4,00% 6,00% Table 75. NPV and Payback of the Investment of Ceiling to attic store proposal 91

110 3.5 Solar Energy proposal Summary information The proposal is use the Solar energy for reduce the consumption of district heating energy. This energy taken of sun it will use of heat water for warm water, so it will reduce the energy consumption of warm water. The decision of use it for warm water and not in space heating is that the warm water is heated until 60ºC doesn t matter in which month and heat the water until 60ºC requires less energy than heated until 80 or 90ºC for heating. The solar collector used in the study was from the Swedish company AQUASOL ( With the sizes of the collectors horizontal and vertical position it was designed the position of the collectors for maximize the total area. For earn more area it was studied too with tilt 90ºC for put flat collectors in south facade in between the fifth floor and the roof. Solar collector s area design is showed in the next table. The facing studied only south because it s the facing that it can get more energy from sun. The tilt chosen is 40º because with this tilt it can get more energy in a whole year and 40º can get more energy from sun in month of july than 45º, this is interesting because it is supposed by the degree days of Gavlegårdarna that in July the don t use district heating for heating, only for warm water. The total energy showed in the next table is in a two buildings system of flat collectors, for Glaciärvägen 21 and 23 is one system, and Pinnmovägen 26 and 24 is other system. Model Height [m] Width [m] Tilt º Number per building Total Number A 2,86 2, B 4,76 2, C 1,91 2, D 0,96 2, E 0,96 4, Table 76. Aquasol s solar collectors models 92

111 Model Area Total Area per building Total Area Construction Useful Construction Useful Construction Useful A 6,6 6,14 6,6 6,14 13,2 12,28 B 11 10, , ,32 C 4,43 4,09 8,86 8,18 17,72 16,36 D 2,23 2,06 4,46 4,12 8,92 8,24 E 4,44 4,10 13,32 12,3 26,64 24,6 Total [m²] 209,24 194,9 418,48 389,8 Table 77. Aquasol s solar collectors models areas Energy report FLAT PLATE COLLECTOR 1 GLASS Average operating t emperature level 70º Slope of surface or traking axis [kwh/m²] (from horizontal) 20º 217,30 25º 231,70 30º 242,90 35º 250,50 40º 254,40 45º 254,40 50º 250,70 55º 243,30 90º 104,50 Table 78. Study of tilt in flat collector 93

112 Slope of surface or traking axis (from horizontal) 40 º MONTH Energy [kwh/m²] Total Area per building Total Area Energy per building [MWh] Total Energy [MWh] JAN 0, ,13 0,26 FEB 5, ,90 1,80 MAR 16, ,99 5,97 APR 22, ,97 7,93 MAY 46, ,36 16,72 JUN 48, ,63 17,27 JUL 43, ,68 15,37 AUG 41, ,36 14,72 SEP 19, ,51 7,01 OCT 9, ,62 3,24 NOV 1, ,22 0,45 DEC 0, ,03 0,07 SUM 254,40 45,40 90,80 Table 79. Flat collectors with 40º tilt Slope of surface or traking axis (from horizontal) 90º MONTH Energy [kwh/m²] Total Area per building Total Area Energy per building [kwh] Total Energy [kwh] JAN 2, ,16 76,32 FEB 7, ,13 242,26 MAR 13, ,03 440,06 APR 8, ,26 280,52 MAY 11, ,25 366,49 JUN 8, ,48 274,97 JUL 9, ,12 308,24 AUG 16, ,29 538,58 SEP 12, ,47 402,95 OCT 10, ,04 350,07 NOV 2, ,39 92,77 DEC 1, ,70 59,41 SUM 104,50 [kwh] 1716, ,63 [MWh] 1,72 3,43 Table 80. Flat collectors with 90º tilt 94

113 Total 40º and 90º MONTH Energy per building [MWh] Total Energy per building group [MWh] JAN 0,17 0,34 FEB 1,02 2,04 MAR 3,21 6,41 APR 4,11 8,21 MAY 8,54 17,08 JUN 8,77 17,54 JUL 7,84 15,68 AUG 7,63 15,26 SEP 3,71 7,42 OCT 1,80 3,59 NOV 0,27 0,54 DEC 0,06 0,13 SUM 47,12 94,23 Table 81. Total Energy of Flat collectors with 40º and 90º tilt Economic report Glaciärvägen 21, Glaciärvägen 23 and Pinnmovägen 26 Cost of energy 0,43 SEK/kWh Investment SEK Duration Investment 30 Years Recovery yearly SEK Energy Savings 188,5 MWh Money savings SEK/year Table 82. Investment Information in Solar energy proposal NPV [SEK] Payback [years] 2,00% 4,00% 6,00% ,00% 4,00% 6,00% > Table 83. NPV and Payback of the Investment of Solar energy proposal 95

114 4 DISCUSSION 4.1 Energy survey: consumption In the analysis of the Energy survey it can be seen that Glaciärvägen buildings waste more energy than Pinnmovägen buildings this is because Pinnmovägen 24 building is a new construction so it is a better system than Glaciärvägen buildings. But a problem due to this was that it can t be known the waste of energy in the buildings of Pinnmovägen 24 and Pinnmovägen 26, because number 24 it is new construction but 26 it is old construction and the information of the energy consumption joins Glaciärvägen buildings and Pinnmovägen buildings due to the district heating net and the district heating rooms, this net was explained in 2.1 District heating net. Due to this situation the information about the consumption of kwh/m² per building in Pinnmovägen 26 and Pinnmovägen 24 are not accorded to the reality because Pinnmovägen 26 will have more waste of energy, and Pinnmovägen 24 will have less, but it is average information that can be managed. Different consumptions per months about heating or warm water can be disconcerting due to one difficulty more, in the apartment s lives students and people who is their residence. The most common is that the students change every year and they don t have the same behavior about waste of warm water or electricity or even some apartments don t have anybody living one year so they have apartments without anybody living there. The students living in these buildings usually they go home in summer months after the end of the courses and exams all this affects to energy consumption and this information is hard to study for all this changes. For example the increase of warm water since September of 2009 in the buildings of Pinnmovägen 26 and 24 it can be explained because now Gavlegårdarna offer one room apartment or one room not for one student, for two students, it is a way for increase the rental of the rooms or apartments but reducing the rental per person, this kind of rooms are offered to Chinese students, so the warm water consumptions rockets easily. It can be seen in figures 38 and

115 The total energy consumption can t be completed due to the lack of information by Gavlegårdarna, the electrical consumption of 2008 and electrical consumption of Pinnmovägen 24 in 2009 and The high consumption of electricity in Glaciärvägen 23 compared with the others buildings it is because this building has laundry room. In the figures 36 and 37 and in the tables of the appendix 7.3 Energy Consumption that in July the buildings have consumption of heating this it can be due to the losses in the heat exchangers that are not counted in the project and internal grid of the buildings and the long route from the district heating room located in Glaciärvägen 23 to Glaciärvägen 21, it is the same with Pinnmovägen buildings, because buildings are separated and the warm water, and heating too, has to come from the district heating room to the other building and provide the energy to the apartments and this is a long route for the pipes. Normal year consumption by moths and total in a Normal year is not calculated due to the different factors of the consumption mentioned before in this section. A way for calculate is relate the degree days of 2009, 2008, Normal year and the consumption of this years and obtain an average of a Normal year consumption and compare it with the consumption results. 4.2 Energy survey: losses Ventilation losses are not calculated in this project, are calculated in other project of Gavlegårdarna and Högskolan i Gävle by Victor Gutierrez Morate, the information given by this project is the losses in year 2009, but it can be calculated roughly for year 2008 and Normal year and then show a complete Energy survey of losses. In the separation of the different elements in the building than take parts in conduction losses per building it can be seen that windows and doors are the element that lose most of the energy, around 50% followed by external walls and ceiling to attic store with 30% and 13% respectively, the rest of losses are in foundation and ceiling to outside elements. 97

116 Almost all the losses in the external walls, 80%, are due to the concrete wall due to his big surface 840 m², it has a U-Value less than 0.5 W/m²K, is not a bad value but it can be improved but it has to be with a wall that keeps the aesthetics of the buildings in Sätra neighborhood, this study is not included in this is project due to the deadline results to Gavlegårdarna. Windows and doors losses as well as ceiling to attic store was studied for improve it. Losses from apartments to landing, the space with the stairs and elevator of the building are not calculated in the project due to Gavlegårdarna didn t give the information about the walls that separate this two areas. Also is not calculated the losses from apartments in the first floor to the space not heated areas of the ground floor due to the difficulty of establish a criteria for the temperature during the months in this space and the unknown materials of the ceiling that separate the ground floor and first floor. This losses wasn t calculated for this two reason but also is because the heated area chosen in the project fits not only with this buildings, fits with a lot of buildings in the Sätra neighborhood, the only difference in the buildings are the ground floor area, so this calculations can be extrapolated to other buildings. Other reason that was not included is because Gavlegårdarna wants to do a redesigning of this area so these spaces can be heated or not in a near future. The same case is with losses from store in the ground floor with these spaces. This lacks of losses can be seen in table 61, because the amount of total losses are less than the district heating energy used by the buildings showed in table 24. The total losses are around 8-10% less that the consumption in district heating energy for heating. 98

117 4.3 Windows proposal With windows proposal it can be saved around 50 MWh per building and per Normal year that s mean a total of SEK per building. Looking the total of the three buildings the number increase 3 times, 150 MWh per building and per Normal year and little more of SEK. Comparing with the actual windows it is a 59.3% of savings. It is a big energy and cost savings but the dark side of this proposal is the high investment that the proposal requires. The Investment was asked in the company Beijer Byggmaterial of Gävle ( This company works with the windows company Elit Fönster AB, the price given includes the installation of the windows too, SEK, it seems too high but it was the only one that was given in time for the project and it was difficult try to find other for compare or search the best one for the proposal. In the Investment study it can be seen that with the terms for the study chosen, constant 6% of interest and 30 years duration, and studying the increase of energy cost, 2%, 4% and 6%, the NPV is always a positive value given profits with increases of 4% and 6% in the years 23 th and 20 th respectively, in the case of 2% only in the last year give profits. 4.4 Ceiling to attic store proposal This proposal saves around 13 MWh per building per Normal year and a total of SEK per building. That s mean a 38 MWh and SEK in the sum of the three buildings. The energy saved in this proposal is 58.15%. The energy saved is not too much but it s a good proposal due to his cheap construction and his big profits in the end of the investment. The Investment is around 500 SEK/m² including the installation. The information is from company Skanska ( through the Högskolan supervisor of the project Roland Forsberg from Sweco Company. It is a reasonable amount for this kind of jobs. 99

118 The investment study give an attractive information, NPV of SEK, SEK and SEK, with an increase of energy cost of 2%, 4% and 6% respectively. It starts to give profits in 5 th year for the 3 cases of increase energy cost. It is an easy construction and it can be done in little time. The other hand of the proposal is the reduction of the temperature in the attic store, is not a heated area so for Gavlegårdarna was not a problem and the law allows it, but for makes it comfortable it was designed with a no less temperature in the attic store of 0º in winter time for a Normal year. The reductions of these losses are important for all the reasons above and because increase comfort in the 5 th floor apartments and it reduce the waste of heating a nonheated space as the attic store is. 4.5 Solar Energy proposal The solar energy proposal saves around 50 MWh per building and per year of warm water, it is a big energy saves. Looking the economy it has an SEK money savings per year of district heating energy cost. It seems a very good way to save energy but like in windows and doors proposal it requires a really big investment, around SEK. This is a big amount and an expensive way for save energy. The economic data was obtained from teacher Björn Klarsson of Högskolan i Gävle due to the difficulty of contact with a company and get information about prices. The price used in the project was a SEK/m² including the installation of the system. The system is not designed in the project and it seems that maybe it can be used this proposal in all the buildings, only in the buildings with district heating room due to the long distance between the buildings, so maybe the final results of this proposal has to be reduce to the half. This information was given has to be studied more and maybe study PV-system for electricity or in the four buildings for see what is the best. This information about the difficulty of the collectors system in the four buildings was given late and it couldn t be changed in the project. 100

119 The investment study for this proposal is a bit negative due to the NPV and Payback results. If the cost of energy increases during 30 years only 2% every year it means it s a bad business, the NPV is negative and the payback more than 30 years, if the increase is 4% the investment is get back in 29 years with a little profits that can be seen in NPV so in this case the energy is reduced during the years but don t get significant profits, and in 6% case it can get big profits, round SEK, from 25 th year of the 30 years of the investment period. 4.6 Energy consumption with proposals In the next table it is showed the total savings per building including the solar panels in Pinnmovägen 24. The information it is showed in MWh and the percentage is the savings compared with the energy consumption of the buildings in the year 2009, it gives the total reduction of energy with the proposals. Improvings [MWh] Glaciärvägen 21 Glaciärvägen 23 Pinnmovägen 26 Pinnmovägen 24 Windows and doors 45,6 45,6 45,6 - Ceiling to Attic savings 8,8 8,8 8,8 - Solar Energy 47,1 47,1 47,1 47,1 Ventilation 100,0 100,0 100,0 - Total savings 201,5 201,5 201,5 47,1 Table 84. Total savings of the proposals in the buildings District Heating Energy 2009 Consumption New consumption Savings [MWh] [kwh]/[m 2 ] [MWh] [kwh]/[m 2 ] Glaciärvägen ,0 275,6 323,6 169,9 38,4% Glaciärvägen ,2 275,6 291,7 163,0 40,8% Pinnmovägen ,1 180,4 141,6 74,5 58,7% Pinnmovägen ,7 180,4 296,6 155,7 13,7% Table 85. New consumption with proposals 101

120 District Heating New consumption Savings 2009 Cost Energy Cost [SEK] Cost Cost Glaciärvägen Glaciärvägen Pinnmovägen Pinnmovägen Total Table 86. New consumption cost with proposals These tables show a resume about how much energy and how much money can reduce in a year with the proposals. It can be seen the direct impact of it. The reduction of the energy is around 40%, in Glaciärvägen buildings, with these proposals it doesn t arrive to the goal of 50-60% of reduction including of course the ventilation savings. Good information is the reduction in the kwh/m² it is reduced from 275 kwh/m² to 160 kwh/m². 102

121 5 CONCLUSION With the proposals for the buildings it can be seen that the objective of retrofitting project together of EURHONET, reduce the energy in 50%-60% is not achieved in this project but it arrive at 40%, the 10%-20% can be achieved with more study and more time due to the deadline and the difficulties for give in the project to the company Gavlegårdarna. This project was thought also for other buildings and not only for this three in the study because the residential floors have the same distribution as other buildings of Gavlegårdarna in Sätra neighborhood. So all the information separated in residential floors of losses can be used for other studies in other buildings. The goal of reduce the energy consumption with this project as it is said before it is almost achieved and this is a big reduction of energy and it goes with the behaivour of take care about the waste of energy and the environment topic that Gavlegårdarna and also Sweden take care. So it is easy to say that with this project or with an improvement of this project Gavlegårdarna improve the environment and it become in a example for other house companies in the world and not only in Sweden. This behavior of Gavlegårdarna give them a good advertisement for future sells because now the buyers not only see if the product is good or cheap also if the company take care about the energy and about the improve behavior. In the investment studies it is difficult to say in some parts that are a good decision or not taking the risk, because there are investments of a lot years and they are calculated with some assumptions and with only one price in the market. If for Gavlegårdarna not lose money and not have big profits in the investment proposals like solar panels or windows will be really good bet in them because the houses will decrease the energy consumption with some proposal they won t win profits but they will win with others. In the end with this project Gavlegårdarna has a good energy survey, that they can use for other buildings too, and some proposals of improve the buildings with their investment studies. Now it is turn of Gavlegårdarna for studied more deep in the economical topic and take a decision about do it in the future and save all the energy and money. 103

122 6 REFERENCES 1 Swedish Energy Agency, Energy in Sweden Swedish Energy Agency, Energy in Sweden Swedish Energy Agency, Energy in Sweden * Figures of Swedish Energy Agency, Energy in Sweden EURHONET Association, 5 Web page: 6 Most normal temperatures used in Gävle. Average of thirty years Web site: ldgs 104

123 7 APPENDICES 7.1 Buildings Plans Glaciärvägen

124

125

126

127

128

129

130

131 7.1.2 Glaciärvägen

132

133

134

135

136

137

138 7.1.3 Pinnmovägen

139

140

141

142

143

144

145 7.2 Sätra District Heating Net Plan 127

146