FACULTY OF ENGINEERING AND SUSTAINABLE DEVELOPMENT
Department of Building, Energy and Environmental EngineeringViktor Archakis
2018
Student thesis, Advanced level (Master degree, one year), 15 HE Energy Engineering
Master Programme in Energy Engineering, Energy Online Supervisor: Professor Taghi Karimipanah
Assistant Supervisor: Roland Forsberg Examiner: Dr. Mathias Cehlin
Preface
At this point I would like to thank my supervisor Professor Taghi Karimipanah for his assistance and the support that he provided to me during the dissertation. Furthermore, I would like to thank Mr. Roland Forsberg for providing me data and drawings of the house and for all his help from the beginning until the end of the project and Arman Ameen, for his advices regarding the IDA ICE software.
Finally, I would like to thank my fiancé Danai Christina Themeli, for supporting me during the dissertation and for proof reading my thesis and my family for the moral support.
Abstract
About 25 % of the total buildings in the European Union have been categorized as ”old buildings”. Followed the recent strickt rules for carbon emissions reduction, each house has to approximetely cut 20 % of CO2 by 2020. Countries like England, have taken the issue very seriously and planning to reduce the carbon emissions by 30 % until the end of 2020 and by an extra 80 % by 2050 (Francis Moran, 2014). The aim of the report is to present how a traditional house can be retroffited into a passive house and also to identify the key points that every passive house should have. For the purpose of the project an avtual house, based in Gävle, was provided and all the simulations are based on actual data. The initial design of the house which was used for the simulation and the 3D design, was provided by the house owner. The building was built in 1953,
information regarding the current insulation of the house was provided by the owner as well. For the simulations and the 3D design a software know as IDA ICE was used, license and access to the software were given by the University of Gävle. The report simulates the current house and compares the results with two possible scenarios that are reducing the energy demand of the house. Furthermore, the possible ways and tools that could be used to reduce the energy demand of the house and cost estimation for the retrofitting is available in the paper.
The first simulations were occured on the actual house, the first retrofitting package introduces new simulations based on new insulation materials, like wood and cement, that are placed mainly on the roof and on the outer walls. Also, the thickness have changed, thus the new insulations are thicker.
Moreover, the second and final retrofitting package, introduces an HVAC system, which is a standard system. The aim is to achieve further energy demand reductions and prove that simple and basic changes can improve the quality of living and reduce CO2 emissions.
After the completition of the first analysis, a reduction equal to 60 % and after the addition of the HVAC a further 20 % reduction achieved.
Table of Contents
1 Introduction... 1
2 The Design of a Passive House ... 3
2.1 Airtightness ... 3
2.2 Ventilation System ... 3
2.3 Solar Power ... 3
2.4 Windows ... 4
2.5 Louver shading devices ... 4
2.6 Heating ... 4
2.7 Building Envelope ... 5
2.8 U-Values ... 5
3 Estimated cost of a passive house ... 7
4 Model ... 9
5 Method ... 13
6 Results ... 15
6.1 Initial Case ... 20
6.2 Retrofit package one ... 24
6.3 Retrofit package two ... 30
7 Conclusion ... 35
8 Future Work ... 37
9 References ... 39
1
1 Introduction
In the EU Union the old buildings are about 25 % of the total number of buildings. It is a challenge for the European countries, because approximately each house will have to reduce its carbon emissions by at 20 % by 2020. Moreover, several countries like the UK have set tougher goals for the regions. In England the government decided to reduce the carbon emissions by 30 % by 2020 and 80 % by 2050 (Francis Moran, 2014). It is a challenge for the UK as more of 35% of the houses in the country have been built before 1946 (Francis Moran, 2014).
From the previous statement, can be seen that the European Union’s main aim is to improve as much as it is possible the energy efficiency of the buildings, which
consumes about 35 % of the total main energy use. Furthermore, Sweden has set its own aims, the Swedish government will reduce total energy use per building by at least 15 % by 2020 and 45 % by 2050. For this measure, the records from 1995 will be used as a reference (Ambrose Dodoo, 2010).
For achieving this aim, more energy buildings should be built which will contribute to the reduction of the carbon dioxide in the following years. The current issue is that the rate of new buildings is low, hence there is no short-term improvement (Ambrose Dodoo, 2010).
Almost 60 % of the total energy use in Sweden is used for space and tap water heating, more than half a million houses are expected to proceed with major renovations in the next years and that create chances of improvement of energy efficiency in Sweden the upcoming years (Ambrose Dodoo, 2010).
The primary goal of the passive house project is to reduce the energy demand, mainly for space heating, and generally cut the required energy for heating and cooling. Thus, reduction in the final energy use for heating can be fulfilled by retrofitting houses to passive house standard (Ambrose Dodoo, 2010).
The passive house standards are different in every region. For example, in Germany and Austria a maximum energy use for heating of 15 kWh/m2/year and total overall
operating main energy use of 120 kWh/m2/year is needed to meet the passive house
standard. Whilst in Sweden, maximum bought energy of 45 to 55 kWh/m2/year, depends the climate zone, is required to fulfil the Swedish passive house requirements (Ambrose Dodoo, 2010).
Some extra standards must be achieved to a building in case the owner is willing to certify the house as a passive building. The main requirement for a passive house certification is the reduction of about 80 % of the current energy demand. The general purpose is to reduce the energy consumption of the house and improve the quality of life and air, to make the building more sustainable and more pleasant for the occupants. The idea of the passive house project created at the University of Lund in the
Department of Building Science by Professor Bo Adamson and Wolfgang Feist in May 1988. Between 1980 and 1990 Adamson worked together with the Ministry of
Construction concerning “Design of energy efficient houses in thePeople’s Republic of China including utilization of passive solar energy”. In that project the need and the use of passive solar space heating was developed. In order to improve the thermal comfort in the building and reduce the energy demand, better insulation, windows and
airtightness were required. The initial project took place in cold climate combined with high solar radiations. The heat, which was produced by the sun was used for space heating. From the results of the project, Professor Adamson and his PhD student,
2 Wolfgang, proved that a passive building is feasible even in cold climates
(Janson, 2010).
After the completion of the research, Adamson and Wolfgang with the assistance of architects Bott and Ridder built the first passive house in Darmstadt, Germany in 1991. Once the house was completed the two researchers had the chance to introduce a new direction for the future buildings. The future buildings would be able to combine energy efficiency, and sustainability with high comfort, affordability and indoor air quality. Four families are currently living in the first passive house building in Darmstadt. After a couple of decades, the annual energy consumption has measured approximately 15 kWh per square meter of living space each year (Institute, 2014)
In general, a passive house has extremely high levels of insulation, good insulated window frames and glazing, good thermal bridges, is an airtight building and has a ventilation system with high heat efficient or energy recovery (Institute, 2014). Each passive building has five main advantages which makes it more attractive compared to the traditional buildings. It has high levels of comfort, produces fresh air throughout the building, structural longevity which reduces the chances of moisture damage, very low heating and cooling costs which are not affected by any possible adjustment on the energy cost and a very improved indoor climate. The heating demand of each passive house is approximately 75 % lower than any other low-energy house (Institute, 2014).
The construction of the passive house varies and it is depending on the local climate. In general, the main principles are almost the same all over the globe, but for example in warm climates the passive cooling measures, like shading and window ventilation are more important, whilst in cooler areas opposite measures are required. Due to that fact, almost every area has different standards. The general standard that each passive house must fulfil are split on five main categories (Institute, 2014).
For space heating, the demand must not go more than 15 kWh per year or 10 W per square meter of usable. Almost identical with the space heating demand are the numbers for the cooling space demand, again it is depended on the climate of each region. The primary energy demand, should not be higher than 120 kWh per year for heating, cooling, hot water and electricity. Regarding the airtightness, maximum of 0.6 air changes hourly at 50 Pascals pressure is allowed. Finally, thermal comfort is required for all the living areas during the year with not more that 10 % of the hours in any given year over 25 °C (Institute, 2014).
There are more than 30 different passive house building certificates, which are required to qualify a passive building, every certificate is accredited by the Passive House Institute. Moreover, in the case of the retrofitting, where passive house materials have been used, there is a certificated which is required and is known as EnerPHit Standard. Furthermore, there are also certified passive house designers and consultants which can assist and provide the correct materials to the engineers (Institute, 2014).
3
2 The Design of a Passive House
There are some important factors which must be covered in the design of the passive houses, that playing a crucial role in the energy demand of the buildings. This sector, will analyse and describe some of the key factors (Janson, 2010).
2.1 Airtightness
Airtightness is one of the most complex sections in a passive house, the target for airtightness in passive building is below 0.6 ACH-1 at 50 Pa for new buildings and less than 1 ACH-1 at 50 Pa for retrofitting houses. There is a 25 % tolerance in the above values, due to possible air leaks that are often spotted to services that installed after the first airtightness test.
There are some typical requirements that must be met at an airtightness test. At least seven readings at five pascals must be taken, minimum one testing at a pressure difference of magnitude more than 50 Pa, no readings must be taken at pressure
differentials of magnitude more than 100 Pa, the zero-flow pressure difference including winds, should have a value of not more than five pascals, furthermore the correlation coefficient r2 has to be more than 0.980 and finally, the airflow exponent n should be between 0.5 and 1. The airflow exponent, n, measures the turbulence of the airflow through the leaks (Jonathan Hines, 2015).
2.2 Ventilation System
A mechanical ventilation system is necessary in passive houses, a good mechanical system supplies air that meets the national requirements. To have a good indoor air quality a value between 0.3 to 0.5 ACH is required, the number is also depending on the area and the local standards. Moreover, a good ventilation system can transform
moisture and carbon dioxide into fresh air, the tenants are able to open or close the windows, but for optimum quality the occupants must open their windows almost every three to four hours for a few minutes. If the ventilation system is placed correctly, then the heat exchanger will not mix the fresh air with exhaust air but it will only dismiss heat to reduce the heating requirements.
Finally, it is important that the mechanical ventilation system has a good efficiency in order to save as much energy in the exhaust air. It must also be silent and have
adjustable filters. The total energy use of the fans has to be low and also the system must have a bypass for the heat exchanger to keep low temperature throughout the summer. Insulation in the ducts could also be needed to reduce the thermal losses (Jonathan Hines, 2015).
2.3 Solar Power
Over the past years the energy need of each building has been increased. For that reason, clean energy is preferred among the other types of energy, hence solar panels are being placed on the roofs of buildings. For the specific house, a 10 kW photovoltaic panels could be placed on the roof (Mirella Mihai, 2017). The estimated cost of that panel is 123000 Swedish kroner, including the installation cost and the inverter. The inverter converts the DC current to AC and distributed, by a board, to the grid to export and import energy. The average energy which will be produced by the PV will be more than 1600 kWh/year which covers a fair percentage of required energy for the house. The payoff period for the photovoltaic panels is between 10 to 12 years. Furthermore, the owner is also able to see electricity and cover part of the expenses by the margin (Anon., 2018 )
4
2.4 Windows
Windows are also important for the design of a passive house, because are allowed to keep cool the house during the summer period and also assisting in avoidance of high space heating. The position that the windows will be placed is also important, because if windows are facing the south side of the building extra advantage can be gained from the solar gains (Janson, 2010).
The windows must be at least triple glazed and a U-value of 0.8 W/m2K should be
achieved. By using triple glazed windows, the tenants won’t understand any thermal discomfort from the temperature differences over the year and that is achieved because the surface temperatures of the windows are identical to the temperature of the
surrounding surfaces (Rob Mcleod, 2014).
2.5 Louver shading devices
Louver shading devices, are mechanisms that are not allowing the sun to enter the house but the light goes through. During the summer, the shading device is blocking the sun, but at the same time wind is passing through and cooling the area. However, during the winter period, the period allows the sun to enter the house, thus increases the
temperature around the areas and increases the heat of the building. The louvers, could be placed on the southeast side of the house at horizontal position and rotate up to 45 degrees (Taleb, 2014).
2.6 Heating
A heating system known as “Unglazed transpired solar façade”, could be installed to increase the heat of the house.
Figure 1 Unglazed transpired solar façade
A metal plate, with holes, is been placed close to the wall at the roof of the building (see figure 1). Furthermore, the metal sheet is warmed by solar radiation, the air which passes through the ventilation holes is being heated and then is ducted into the house through the fun that is connected to the main ventilation system. Studies have shown that this heating system could save up to 1 MWh/m2 /year of energy consumption. The
5 savings relate to the solar collector design. The cost of the project is not high and is suitable for retrofitting (Hoy-Yen Chan, 2010).
2.7 Building Envelope
The requirements for a passive house are different and are defined by its location. The same principal applies to the construction plans that are used for every passive house. For example, the passive buildings in Central Europe cannot have the same principals with those in Northern Europe and in the rest of the world. The most important is to create a construction that meets the local requirements of each location, local buildings and traditional houses should also be considered as an example.
A way to reduce the cost and improve the quality of a new passive house is with prefabrication. Passive houses are almost similar to standard buildings and no special requirements for construction are required. The minimization of thermal bridges is something that all the types of buildings must aim for.
The reduction of peak load on the heating system and the elimination of cold down draught can be achieved by using well insulated doors and windows. The position of the windows in the house, plays a significant role in the passive solar gains. If the windows are facing the south side of the house, the optimal solar gain can be made. Nonetheless, for the Scandinavian climates the solar gains are low, especially during the winter season, but a correct positioning of the windows could improve the heating of the house in the cold months by allowing the sun to enter the building. Furthermore, an overhang like a roof could also decrease the outer condensation on the window pane (Janson, 2010).
2.8 U-Values
The average value of “opaque” building envelopes in Swedish passive buildings is approximately 0.1 W/m2K. In other places in Europe that number is different, but the mean U-value of the building envelope (walls, roof, floors) must be less than 0.15 W/m2K. To reduce the U-values, well insulated materials should be used. A good
example is the U-value of the outer wall. If the aim is to get a value close to 0.13 W/m2K, then at least 15.8 metres of concrete with thermal conductivity equal to 2.1 W/mK or six meters of solid brick with thermal conductivity of 0.8 W/mK has to be used.
The benefit of having windows with low U-values is not only for low heat losses, it also assists to reach and keep comfortable temperatures during cold outdoor conditions. Moreover, improves the comfort experienced by occupants. For example, a window with U-value of less than 0.8 W/m2K , in Middle Europe, has a result a better comfort for the occupants, directly in front of the window, which is positive when there is no radiator.
Windows must have to be in the correct position to keep the thermal bridges low. In case the windows are placed in the insulation place on the thermal envelope and the insulation overlaps the window frame, the thermal bridge loss coefficient could be close to zero. In any other case, the average U-value could be increased by 50 %
7
3 Estimated cost of a passive house
The cost of a passive house varies and depends on the preferences of the owner. Moreover, the price is affected by the design and by the category of certificate that the architect selects. For an example a finished house designed by EkoBuilt can cost up to $337130. The concrete floor costs $3750, a weather tight installation will cost $33563, the total cost for the roof is $15500, while the HVAC (heating, ventilation, air
conditioning) and insulation cost $15000 and $12500 respectively. Moreover, there are some minor prices for electricity, plumbing, drywall, interior finishes and siding and trim. The specific home is 1424 square feet with three bedrooms and two bathrooms (Anon., 2018).
The annual energy demand for a passive house is about 8628 kWh/yr, whilst a normal building requires 39300 kWh/yr, almost 30000 kWh/yr extra energy is needed for traditional house.
In Sweden, the costs are different and each component has its own price. For the retrofitting, better insulation is required, thus cost of each material must be considered and included in the total cost of the house. Furthermore, the cost of the material dependeds on the amount that is required. The main tools that needed are cement and wood. Cement was placed for external insulation whilst wood was used for internal purposes.
In 2017, the factor price index for new building increased approximately by 0.5 %, between April and May 2017 in Sweden. Moreover, the contractor’s costs increased by 0.6 %, while the construction materials by 0.1 %. The electrical materials noted the highest increase, whilst iron, steel, concrete, woodwork didn’t rise much (Jonsson, 2018).
From 2016 to 2017, the factor price rose by 2.7 %, the contractor’s costs increased by 2.9 % and a 4.5 % increase noted in fuel and electric power which affected the
contractor’s cost (Jonsson, 2018).
It is not possible to accurately estimate the exact cost of a passive house or how much a retrofitting will cost but there are certain optional factors that affecting the final cost of the building and improving the performance at the same time.
First is the continuous layer, that is used for super insulation. It is positioned over the entire building and have zero thermal bridging. The insulation requires to perform resistance values R20 for basement, R40 for walls and R60 for the roof (Freeman, 2018).
The second factor is related to the high-performance windows and doors. Triple paned, airtight windows and doors to reduce the heat loss and keeping the daylight and passive solar energy. All windows and doors should have a U-value equal and less than 0.14. Windows with “low-e” are not keeping the unwanted solar heat gain (Freeman, 2018). The HVAC is responsible for the thermal balance of the house. Thus, it controls the heat, coolness and moisture. These conditions could also be altered by using mechanical space conditioning systems (Freeman, 2018).
The blower door tested building envelope, is another premium tool that could be used for extra comfort in the house. The role of that tool is to prevent the outside air to enter the house, hence reduces the losses. For a passive house the requirement that should be meet is 0.6 ACH50 (Freeman, 2018).
Finally, the optimal orientation assists the building to use at its maximum the sun and collect energy for heating and cooling during the warm and cold months respectively (Freeman, 2018).
9
4 Model
A traditional house model was required for this project, the house that was used is a three-floor building based in Sweden. The drawings provided by the current owner of the house and details regarding the size of the rooms and the height of the floors were included.
Figure 2 Southeast view
The southeast view of the house presents an overall picture of the dimensions and the layout of the building. The small building with the window which is attached to the main house is the garage. Furthermore, there is an entrance from the balcony.
Figure 3 Southwest view
From the next picture, more details regarding the basement and the entrances can be observed. There are two main entrances to the house, one is from the terrace which is connected to the living room and the other again from the balcony that is connected to the hall and the kitchen. Moreover, there is a small window in the roof of the house, but the top floor doesn’t have any rooms.
10
Figure 4 Section of the house
The figure 4, presents the actual height of the rooms. It can be seen that the distance from the basement to the first floor is 2250 mm and from the first floor to the loft is 2450 mm. The line that goes through the building represents the ground. The dimensions of the house are 12.6 x 15.5 meters.
Figure 5 Basement
The floor that is presented above is the basement. That floor has seven rooms, two storage rooms, one large room, one food cellar, a laundry room, a small library and the boiler of the house. Furthermore, there stairs are being placed in one of the storage
11 rooms, which connects the basement with the first floor. Moreover, in the basement there are eleven windows and five doors.
Figure 6 First floor
The next floor is the ground floor. Two bedrooms, one toilet, two balconies, one living room and a hall that it is in the same room with the kitchen are composing the first floor. Moreover, the garage is attached on the outside side of the house. There are also two stairs one relates to the basement and the other to the loft. Finally, the floor has in total eleven windows and ten doors. In the garage, there are two doors, one is the main for the vehicles and the other a smaller one for entering and exiting from the room. The final floor of the house is the loft. It is the only floor that doesn’t have any rooms neither doors. There are only stairs and a window.
For all the simulations of the house, the actual drawings were used with the real dimensions of the rooms and the exact number of windows and doors.
12 .
13
5 Method
For the research, the IDA ICE software was used. IDA Indoor Climate and Energy has been created by EQUA and it is a simulation tool. EQUA appeared for the first time in the eighties at the Swedish Institution of Applied Mathematics and it was used for a specific program which was funded for an oil and gas company. The first sample of the IDA Simulation software was published in 1989 (EQUA, 2018). Access to the software provided by the University of Gävle and was mainly used for simulation and design purposes.
Furthermore, for the report, actual dimensions and drawings of a house located in Gavle were provided by its owner and the 3D design can be seen in the next chapter. All the simulations were applied on the actual house and data collected for all the scenarios that were needed. Moreover, information which was used for the initial scenario, like
insulation material and thickness were also given. Data which were missing but were required for the simulations were assumed. For example, thermal bridges assumed to be on a typical level, the occupants placed in large rooms like bedroom and kitchen, output air value was also assumed.
For retrofitting package one and two, possible tools that can be used for the refurbishment of the building were applied. The first scenario reduced the energy demand by about 60 %, while the second one by 20 % extra reduction in the energy demand. Total 80 % of reduction was achieved by combining the two projects. The changes that were made on the house and used for simulations in the two scenarios are feasible and payoff is applied in a short period of time.
The first case, simply improves the insulation of the building, by changing the material and the thickness of the insulation. The new materials and thickness size were selected after a research and those materials (mainly cement and wood) have low heat loss and low U-values. Improvement of the insulation was mainly needed in the outer walls and on the roof, these are the places which the most losses occur. For the outer walls and the roof, the material that was preferred was cement, whilst for the inner walls and floors, wood was the appropriate material. Windows were also improved by three glazed to four double glazed and finally the thermal bridge conditions improved from typical to good.
The second and final case, is similar to the first one with the only difference that a standard HVAC system is installed in the house. The purpose of that example is to show the difference that a good air handle system can make to a house and also to prove that these changes improving the quality of living in the house. By applying only that change, the energy demand of the building is reduced by almost 20 %.
More ways to improve and reach the required energy demand that each passive house must meet, have been presented above. The two examples are based on economically feasible solutions and suggested as two simple ways to reduce the energy demand and the yearly costs of the building. Moreover, the alterations are improving the quality of life of the occupants.
All the simulations were made for the period of one year, from 01/01/2017 until 31/12/2017. That period was selected because the 2018 year have not been completed yet, hence the data will not be accurate. In addition, for the weather and temperature data, logs from the local area was used. That way allows to have accurate and precise data from the region that the house is placed.
15
6 Results
This section presents the results that were obtained after the simulation of the three models. The initial model shows the actual data of the house, whilst the other two simulations present the results after applying upgrades on the house, also a comparison with the initial model is also presented.
An assumption that was made for the simulation, is that the outer doors and windows are always closed, whilst the inner doors are open. The specific names of each room in the house and the initial drawings are placed in the previous sections.
As it was mentioned, the initial model is based on actual drawings and dimensions which were given.
Figure 8 Basement
The figure above, presents the basement of the house, the blue lines indicating the zones that created to cover the rooms on each floor, the yellow the doors and the light blue are the windows of the apartment. In the basement the windows are located on the upper half of the walls and are slightly above the ground, which allows the sun and the light to enter the basement.
The following fixture reveals the drawings that made in IDA ICE software for the first floor of the building.
16
Figure 9 First floor
Like the previous figure, the blue lines are for the zones, the yellow for the doors and the light blue for the windows. It can also have been seen that there are grey zones which indicating the zones of the basement. The only room with no zone, is the book room and that is because above the room there is a porch and a door which can be used as an entranced for the house. Another entrance is located on “f3a” which is from the hall/kitchen of the house.
17
Figure 10 Attic
Figure 10, is the final and represents the top floor of the building, also known as the attic. It is a simple floor, compared to the previous floors and does not have any room neither windows or doors. It is an important section of the building, as the attics are responsible for a large percentage of energy loss. The garage and the porch are not connected with the attic, the garage has its own roof and the porch has not the roof. The grey sections represent the floors below the attic.
The “f” following by a number or a symbol indicate the face of the wall and was used while the drawings was setting up for the simulation.
The previous figures represent the drawings of the building, the following graphs presents the 3D layouts of the building which were used for the better understanding of the complexity of the building, the accurate connection between the zones and the nodes has a result a better representation of the house. In case there is a big overlapping in the zones, issues will appear on the simulation, hence corrections will be required.
18
Figure 11 3D representation of the house
In figure 11, the three floors of the house can be observed. Furthermore, the layout of the doors and windows can be seen. The room that is attached on the side of the building is the garage, the black surfaces at the top of the house and on the top of the garage represent the roof. The surfaces in the basement are connected to ground whilst the rest of the walls are connecting on the appropriate faces. The white surface
represents the entrance from the porch, it is white because there are stairs and assumed to have been placed at the entrance.
Figure 12 3D layout, Front view of the house
The graph above shows the front view of the house, whilst the figure 13 presents the back side of the building. On these drawings, the position of the windows in the basement can be noted. As mentioned before, there are placed on the upper half of the wall and just a bit above the ground.
19
Figure 13 Back side of the building
The final picture of the 3D layout, shows the design of all the floors and how the inside of the house looks. In white, the inner rooms are represented and also the inner windows and doors can be seen.
20
6.1 Initial Case
The chapter presents the results of the initial case, that is based on actual information which provided for this paper.
Table 1 Systems Energy
Systems energy kWh Zone heating 32899,1 Zone cooling 0 AHU heating 0 AHU cooling 0
Dom. hot water 6170,9
Cooling 0
Heating 39070
From the table above the total energy demand for the house can be observed. After the simulation the heating demand for one year is 39070 kWh.
Figure 15 Energy losses
The figure above, presents the energy losses in all zones. It can be seen that most losses are creating by envelope and thermal bridges, mainly during heating. Openings are also causing losses, but less compared to thermal bridges. The following figure, shows the graph of the losses, during a twelve month period.
21
Figure 16 Net losses
Below the graphs are showing more detailed and specific data regarding the losses of the building over 12 month period.
Figure 17 Detailed losses of the building
As it can be being seen most of the energy losses of the building are in walls, a result that was expected and occurs due to poor insulation. The roof is the second area that affects the energy demand of the house, again the roofs are usually have high energy losses. Floor and windows are also affecting the total energy of the house, but not as much as the walls and the roof.
22
Figure 18
Winter is affecting the energy demand of the building, the graph above is a twelve-month representation of the energy losses. December and January are the two twelve-months with the highest losses.
23
Table 2 U-values Initial Case
In the above table, a representation of the U-value of each material is presented, highlighted. It is important for the reduction of the losses to use materials with low U-values, by that way the insulation is better and the losses are reduced.
The thickness, material, the type and the areas that each one is connected it to, are included in the table.
Moreover, the last graph of the initial scenario displays the temperature in the house over the year related to the return air dry bulb temperature.
Type Wetted area, m2 Connecte d to Azimuth, Deg Slope, Deg Construct ion U-value, W/(m2 K) Thicknes s, m Layer material Layer thickness , m Layer material Layer thickness , m Layer material Ext. floor 18,32 Ground 0 [Default] Concrete floor 250mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 18,32 Bedroom 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Ext. wall 9,338 Building body.f1c; Ground0 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 8,152 Room 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 8,336 TVroom; Passage180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation 65% Ext. wall 9,752 Garage 270 90 <mixed> <mixed> 0.27 / 0.146
Ext. floor 15,03 Ground 0 [Default] Concrete floor 250mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 15,03 Hall/Kitchen; Bedroom2; WC; Bedroom180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 5,829 Passage room 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 4,994 TVroom 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 2,275 Foodcellar 180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 4,318 Foodcellar 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. wall 4,556 Building body.f3c; Ground180 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 11,21 Building body.f4a; Ground270 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. floor 11,67 Ground 0 [Default] Concrete floor 250mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 11,67 Hall/Kitchen; Bedroom2; Living room; Bedroom180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 7,07 Room; Passage room0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 8,694 Boiler room 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation 72% Ext. wall 6,569 Foodcellar; Building body.f3a; Ground180 90 <mixed> <mixed> 0.27 / 0.146
Int. wall 1,771 Foodcellar 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 0,1518 None 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 5,323 Passage 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. floor 14,34 Ground 0 [Default] Concrete floor 250mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 14,34 Hall/Kitchen; Living room 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 8,68 Room 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. wall 7,613 Building body.f2; Ground90 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 8,455 Building body.f3a; Ground180 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 0,4278 None 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 8,74 TVroom 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. floor 3,723 Ground 0 [Default] Concrete floor 250mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 3,723 Bedroom2 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 2,001 Passage 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 1,84 TVroom 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 2,208 TVroom 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. wall 3,804 Building body.f3b; Ground90 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 4,209 Building body.f3c; Ground180 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 4,044 Passage 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. floor 20,92 TVroom; Passage; Passage room0 [Default] Concrete floor 150mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 20,92 Attic 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Ext. wall 10,01 Building body.f1c 0 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 10,31 Living room 90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 3,83 Hall/Kitchen 180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 0,02 None 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 5,555 WC 180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation 56% Int. wall 11,89 Garage 270 90 <mixed> <mixed> 0.27 / 0.146
Int. floor 27,32 Room; Boiler room; TVroom 0 [Default] Concrete floor 150mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 27,32 Attic 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Ext. wall 4,55 Building body.f1c 0 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 0,0375 None 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. wall 8,365 Building body.f1e 0 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 10,63 Building body.f2 90 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. wall 12,92 Hall/Kitchen 180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 10,14 Bedroom 270 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. floor 3,55 Passage 0 [Default] Concrete floor 150mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 3,55 Attic 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 5,448 Bedroom 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 2,472 Hall/Kitchen; Hall/Kitchen90 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 5,448 Bedroom2 180 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Ext. wall 4,072 Building body.f4a270 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. floor 14,15 Foodcellar; TVroom; Passage 0 [Default] Concrete floor 150mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 14,15 Attic 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood Int. wall 5,665 WC 359,9241 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation Int. wall 3,343 Hall/Kitchen 0 90 [Default] Interior wall with insulation0,6187 0,146 Gypsum 0,026 © Air in 30 mm vert. air gap0,032 Light insulation 99% Int. wall 4,278 Hall/Kitchen 90 90 <mixed> <mixed> 0.27 / 0.146
Ext. wall 0,2825 Building body.f3b180 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 4,173 Building body.f3b90 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 9,353 Building body.f3c180 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Ext. wall 8,442 Building body.f4a270 90 [Default] Rendered l/w concrete wall 2500,5372 0,27 Render 0,01 L/W concrete 0,25 Render Int. floor 22,57 Boiler room; TVroom; Passage0 [Default] Concrete floor 150mm0,85 0,146 Wood 0,016 Light insulation 0,03 Concrete Int ceiling 22,57 Attic 180 [Default] Concrete floor 150mm0,85 0,146 Concrete 0,1 Light insulation 0,03 Wood
24
Figure 18 Temperature over the year
6.2 Retrofit package one
For the first scenario, the assumptions that were made at the initial case and generally for this project were used as well.
In this chapter, the thermal bridges of the building have been improved from typical to good, also new insulation materials have been used. The materials are mainly wood and concrete. Changes applied on the roof and the outer walls, both surfaces have now better insulation and the thickness of the insulation increased. Furthermore, small changes also applied on the inner surfaces and walls of the house, to slightly increase the insulation by using wooded material with low U-value.
As the building is already built, it is suggested to change the insulations during
maintenance or after some years, which changes or improvements on the house will be needed. By that way the cost for the retrofitting will not be high, because the
improvement on the insulation of the house will be already planned and will be achieved during maintenance.
The results are presenting an energy loss reduction compared to the initial case.
Table 2 Energy demand for the first retrofitting package
Systems energy kWh Zone heating 8687,4 Zone cooling 0 AHU heating 0 AHU cooling 0 Dom. hot water 6170,9 Cooling 0 Heating 14860
25 The yearly energy demand is 14680 kWh, whilst in the previous case it was 39070 kWh, a reduction of about 62 % have been achieved after these changes.
Figure 19 Energy losses
Figure 20, presents the energy losses of the building after the changes applied. The most losses are noted in the infiltration and openings and in the thermal bridges. By
comparing the results of the two cases, it can be seen that the losses on the thermal bridges have been reduced and that achieved with the improvements on the thermal bridges and the insulations of the house.
Figure 20 Thermal losses
The graph shows an overall of the losses that presented above, it can be also seen that in December and January the losses were higher compared to the other months.
26
Figure 21 Detailed losses
It can be noted that a significant improvement in the energy losses has been achieved. On the initial case the total losses due to the walls was 14272 kWh, whilst in this case is just 3615 kWh. The same can be noted for the roof, the initial number was 13507 kWh and after the new insulations on the roof the losses are 1266 kWh. An average reduction of about 80 % have been achieved in both cases.
Figure 22 Detailed results of energy losses
It can be also seen that in November and January there was a positive value for the walls. That means that less energy is required for heating the building, thus less expenses over the years for the house owners.
27
Figure 23 HVAC System
As it was mentioned earlier, for the current scenario only insulation and thermal bridges have been upgraded. The HVAC system remained the same as the original one, it can be seen in the figure above. It is a simple return air system which is connected in every room.
28 Moreover, the plant system remained the same as well. A standard plant system was used for this project, with an average temperature of 17 °C. On the graph above the boiler and chiller operations can be seen and the connection between the nodes of the house is also included in the graph.
Figure 25 Thermal Bridges
Furthermore, a figure of the condition of the thermal bridges is presented. It can be seen that the U-value is low for all the parts, the table below shows more details regarding the U-value on each material.
29 The main insulation materials are concrete, wood and gypsum. It is clear that the
average U-value is below 0.13, that improves the insulation of the house and decreases the energy losses.
Name Group Type
Wetted area, m2 Connecte d to Azimuth, Deg Slope, Deg Construct ion U-value, W/(m2 K) Thicknes s, m Layer material Passage room.Floor Ext. floor 18,32 Ground 0 [Default] Concrete floor 250mm0,1349 1,106 Wood Passage room.CeilingInt ceiling 18,32 Bedroom 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Passage room.Wall 1Ext. wall 9,338 Building body.f1c; Ground0 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Passage room.Wall 2Int. wall 8,152 Room 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage room.Wall 3Int. wall 8,336 TVroom; Passage180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage room.Wall 465% Ext. wall 9,752 Garage 270 90 <mixed> <mixed> 17.3 / 1.042 Passage.Floor Ext. floor 15,03 Ground 0 [Default] Concrete floor 250mm0,1349 1,106 Wood Passage.Ceiling Int ceiling 15,03 Hall/Kitchen; Bedroom2; WC; Bedroom180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Passage.Wall 1 Int. wall 5,829 Passage room 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage.Wall 2 Int. wall 4,994 TVroom 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage.Wall 3 Int. wall 2,275 Foodcellar 180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage.Wall 4 Int. wall 4,318 Foodcellar 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Passage.Wall 5 Ext. wall 4,556 Building body.f3c; Ground180 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Passage.Wall 6 Ext. wall 11,21 Building body.f4a; Ground270 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete TVroom.Floor Ext. floor 11,67 Ground 0 [Default] Concrete floor 250mm0,1349 1,106 Wood TVroom.Ceiling Int ceiling 11,67 Hall/Kitchen; Bedroom2; Living room; Bedroom180 [Default] Concrete floor 150mm0,1349 1,106 Concrete TVroom.Wall 1 Int. wall 7,07 Room; Passage room0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum TVroom.Wall 2 Int. wall 8,694 Boiler room 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum TVroom.Wall 3 72% Ext. wall 6,569 Foodcellar; Building body.f3a; Ground180 90 <mixed> <mixed> 17.3 / 1.042 TVroom.Wall 4 Int. wall 1,771 Foodcellar 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum TVroom.Wall 5 Int. wall 0,1518 None 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum TVroom.Wall 6 Int. wall 5,323 Passage 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Boiler room.Floor Ext. floor 14,34 Ground 0 [Default] Concrete floor 250mm0,1349 1,106 Wood Boiler room.Ceiling Int ceiling 14,34 Hall/Kitchen; Living room 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Boiler room.Wall 1 Int. wall 8,68 Room 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Boiler room.Wall 2 Ext. wall 7,613 Building body.f2; Ground90 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Boiler room.Wall 3 Ext. wall 8,455 Building body.f3a; Ground180 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Boiler room.Wall 4 Int. wall 0,4278 None 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Boiler room.Wall 5 Int. wall 8,74 TVroom 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Foodcellar.Floor Ext. floor 3,723 Ground 0 [Default] Concrete floor 250mm0,1349 1,106 Wood Foodcellar.Ceiling Int ceiling 3,723 Bedroom2 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Foodcellar.Wall 1 Int. wall 2,001 Passage 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Foodcellar.Wall 2 Int. wall 1,84 TVroom 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Foodcellar.Wall 3 Int. wall 2,208 TVroom 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Foodcellar.Wall 4 Ext. wall 3,804 Building body.f3b; Ground90 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Foodcellar.Wall 5 Ext. wall 4,209 Building body.f3c; Ground180 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Foodcellar.Wall 6 Int. wall 4,044 Passage 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Bedroom.Floor Int. floor 20,92 TVroom; Passage; Passage room0 [Default] Concrete floor 150mm0,1349 1,106 Wood Bedroom.Ceiling Int ceiling 20,92 Attic 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Bedroom.Wall 1 Ext. wall 10,01 Building body.f1c 0 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Bedroom.Wall 2 Int. wall 10,31 Living room 90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Bedroom.Wall 3 Int. wall 3,83 Hall/Kitchen 180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Bedroom.Wall 4 Int. wall 0,02 None 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Bedroom.Wall 5 Int. wall 5,555 WC 180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Bedroom.Wall 6 56% Int. wall 11,89 Garage 270 90 <mixed> <mixed> 17.3 / 1.042 Living room.Floor Int. floor 27,32 Room; Boiler room; TVroom 0 [Default] Concrete floor 150mm0,1349 1,106 Wood Living room.Ceiling Int ceiling 27,32 Attic 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete Living room.Wall 1 Ext. wall 4,55 Building body.f1c 0 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Living room.Wall 2 Int. wall 0,0375 None 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Living room.Wall 3 Ext. wall 8,365 Building body.f1e 0 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Living room.Wall 4 Ext. wall 10,63 Building body.f2 90 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete Living room.Wall 5 Int. wall 12,92 Hall/Kitchen 180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum Living room.Wall 6 Int. wall 10,14 Bedroom 270 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum WC.Floor Int. floor 3,55 Passage 0 [Default] Concrete floor 150mm0,1349 1,106 Wood WC.Ceiling Int ceiling 3,55 Attic 180 [Default] Concrete floor 150mm0,1349 1,106 Concrete WC.Wall 1 Int. wall 5,448 Bedroom 0 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum WC.Wall 2 Int. wall 2,472 Hall/Kitchen; Hall/Kitchen90 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum WC.Wall 3 Int. wall 5,448 Bedroom2 180 90 [Default] Interior wall with insulation0,1337 1,042 Gypsum WC.Wall 4 Ext. wall 4,072 Building body.f4a270 90 [Default] Rendered l/w concrete wall 2500,09665 17,3 Concrete
30
6.3 Retrofit package two
The second scenario is the final one, it uses the results and data from the previous case with the only difference that a better HVAC have been install in the house. The
difference, as it can be seen is significant and proves that a good ventilation system can make the difference in the quality of a building.
Table 4 Energy Demand
Systems energy kWh Zone heating 345,7 Zone cooling 0 AHU heating 1355,1 AHU cooling 355,6 Dom. hot water 6170,9
Cooling 355,6
Heating 7872
The table presents the total energy demand for the house for one year. The difference with the previous cases is that there is a cooling demand as well and that is because the ventilation system keeps constant the temperature of the house at 17 °C.
Figure 26 HVAC system
It is a standard air handling unit, with heat exchanger and fan operations, air supply and air exhaust systems and with heat and cooling systems. The supply air temperature is set to a constant 17 °C.
With that addition, there is an 80 % reduction in the energy demand of the house, compared to the initial structure and a further 46 % compared to the previous case.
31 The diagram of the plant is the same with the one in the last case (Figure 25), also the thermal bridges are also the same as no change applied to them.
Figure 27 Energy losses
The losses in the thermal bridges are less compared to the losses on the package one. Also, the walls have improved the heat and energy losses. In some periods the results are positive, which indicating zero heat losses thus less energy demand for the cooling and heating of the house.
Figure 28 Multizone
More detailed results for each system are presented on the diagram above. It can be seen on which period of the year, each system gaining or losses energy and which months are affecting the energy demand of the building.
32
Figure 29 Transmission details
In the above figure, the losses on each part of the house are displayed. As it was expected the number are lower compared to the previous cases. Especially during the heating, the energy losses in walls and roof have been decreased by about 81 % and 28 % respectively
The results can be also be seen in the graph below, which shows a diagram of the losses during 365 days.
33
Figure 31 Total heating and cooling
The total heating and cooling of the house is presented above, it is clear that the most heating energy consumption takes place in December, whilst energy for cooling is needed during the summer months. The figure also displays the values for domestic hot water, ideal coolers and heaters, the required AHU heating coil power and the AHU cooling coil power.
Figure 32 Used Energy
The used energy of the building can be observed above, AHU heating and hot water have the highest values, while zone heating and AHU cooling do not require much usage energy.
The U-value of the materials have not been changed, because the insulation materials remained the same with the first scenario.
34
Table 5 Delivered energy
Delivered Energy Meter Total, kWh Per m2, kWh/m2 Peak demand, kW Lighting, facility 7994,4 25,91 1,197 HVAC aux 1322,4 4,286 0,1588 District cooling 355,6 1,152 1,573 District heating 7871,9 25,52 3,687 Equipment, tenant 5550,6 17,99 0,8 Total 23094,9 74,858 7,4158
The table shows where the energy has been distributed, the heating and lighting consumes large amount of energy followed by the equipment in the house and the tenants. The low consumption level for cooling was expected, as the house is in a northern country where the temperatures are not high during the season, only the summer the temperature can rise.
35
7 Conclusion
The results of the above scenarios, are indicating that after the retrofitting the house will reduce the energy demand by about 80 %, the first retrofit package improves the
condition of the house by almost 60 % whilst the HVAC system which was placed in the second package contributes to a 20 % reduction in the energy demand. The expenses for the additions and the changes will be paid off in a short period of time due to the savings that the house provides the owner through the energy consumption reductions. As it is mentioned in the previous chapters, it is difficult to estimate the exact cost of the retrofitting, as it is depended on the service and material costs and the owner’s selection on which package prefers. Furthermore, the expenses are depended on the owner’s willingness to apply for a passive house certificate or simply reduce the energy demand and improve the comfort of the house.
In the case of the solar panel, the payoff time is estimated to 12 years, but with that addition the house will require less energy and will be more efficient. In the design of a passive section, there are some additional changes that are suggested but are not
included in the scenarios. The reason is because the report presents two feasible and low-cost scenarios which can be implemented in a short period of time.
Even if the owner is not willing to proceed with both cases, the first scenario is enough to reduce the demand by almost 60 % and improve the quality of air and life in the house.
The walls and the roof are the two main areas which affecting the energy demand of the building. Usually the external walls require thicker insulation, furthermore for the roof material like concrete is good to be used.
In Europe, there are more than 85 certified passive houses, whilst in Sweden the total number of the passive houses are thirteen. Only one of them has been retrofitted and is in Gothenburg, the building was built in 1969, composed of by several apartments and in total is 3320 m2 (Passivehaus-Datenbank, 2019)
37
8 Future Work
More focus to subjects related to future techonologies that could be used in order to reduce the emissions and improve the quality of live on every house and also on materials which can be used with lower cost and less U-value than wood and cement. Finally, a deeper research on renewable souces like wind power and hydro power that combined with solar panels can deliver extra energy resources could also be considered as future projects.
39
9 References
1. Ambrose Dodoo, L. G. S., 2010. Resource,Conservation and Recycling. Life cycle
primary energy implication of retrofitting a wood-framed apartment building to passive house standard, pp. 1152-1160.
2. Anon., 2018 . Svea Solar. [Online]
Available at: https://sveasolar.se/solceller/ 3. Anon., 2018. ekoBuilt. [Online]
Available at: https://ekobuilt.com/ekobuilts-services/ottawa-passive-house/cost-analysis-for-building-an-eko-passive-house/
4. EQUA, 2018. EQUA. [Online]
Available at: https://www.equa.se/en/about-us/history
5. Francis Moran, T. B. S. N. A. S., 2014. Energy Buildings. The Use of Passive House
Planning Package to reduce energy use and CO2 emmisions in historic dwellings, pp.
216-217.
6. Freeman, R., 2018. POPLAR. [Online]
Available at: https://www.poplarnetwork.com/news/what-does-passive-house-cost 7. Hoy-Yen Chan, S. B. R. J. Z., 2010. Renewable and Sustainable Energy Reviews. Revuew
of passive sikar heating and cooling technologies, pp. 781-789.
8. Institute, P. H., 2014. Active for more comfort:Passive House. Darmstad: International Passive House Association.
9. Jonathan Hines, S. G. B. B. M. S. P. J. N. G. C. M. P., 2015. How to build a
passivhaus:Rules of Thumb. How to build a passivhaus:Rules of Thumb, pp. 4-42. 10. Jonsson, J., 2018. SCB. [Online]
Available at: http://www.scb.se/en/finding-statistics/statistics-by-subject-area/prices-
and-consumption/building-price-index-and-construction-cost-index-for- bu/construction-cost-index-for-buildings-cci-input-price-index/pong/statistical-news/constuction-cost-index-for-
11. Mirella Mihai, V. T. D. A. B. V., 2017. Energy Buildings. Passiv house analysis in terms of
energy perfomance, pp. 74-86.
12. Passivehaus-Datenbank, 2019. Passivehaus-Datenbank. [Online] Available at: Passivehaus-Datenbank
13. Rob Mcleod, K. M. S., 2014. Passivhaus primer:Designer's guide. Passivhaus
primer:Designer's guide, pp. 1-12.
14. Taleb, H. M., 2014. Frontiers of Architectural Research. Using passive cooling strategies
to iprove thermal perfomance and reduce energy consumption of residential buildings in U.A.E. buldings, pp. 154-165.
15. Janson, U., 2010. Passive Houses in Sweden. From Design to Evaluation of Four
41
Appendix A
Table 1 Delivered Energy Initial Case
Delivered Energy Meter Total, kWh Per m2, kWh/m2 Peak demand, kW Cost CO2 Emission, kg Primary energy, kWh Lighting, facility 7994,2 25,91 1,197 HVAC aux 629,2 2,04 0,07183 District cooling 0 0 0 District heating 39070,5 126,6 17,43 Equipment, tenant 5550,5 17,99 0,8 Total 53244,4 172,54 19,49883 0 0 0
Table 2 Energy Balance Initial Case
Energy balance (sensible only)
Envelope & Thermal bridges, kWh Internal Walls and Masses, kWh Window & Solar, kWh Mech. supply air, kWh Infiltra-tion & Openings, kWh Occu-pants, kWh Equip-ment, kWh Lighting, kWh Local heating units, kWh Total -33625,3 12,1 1424,9 0 -16678,2 2399,8 5550,7 7994,4 32897,9 During heating -30569,4 579,1 -107,6 0 -14531 1663,4 3780,3 6267,5 32899,2 During cooling -1872,4 -550,2 1016,1 0 -1308,4 478,2 1184,3 1048,1 0 Rest of time -1183,4 -16,8 516,4 0 -838,8 258,2 586,1 678,8 -1,3
Table 3 Energy Balance Retrofitting package one
Energy balance (sensible only)
Envelope & Thermal bridges, kWh Internal Walls and Masses, kWh Window & Solar, kWh Mech. supply air, kWh Infiltra-tion & Openings, kWh Occu-pants, kWh Equip-ment, kWh Lighting, kWh Local heating units, kWh Total -8071,3 80,1 1412,2 0 -17871,3 2192,3 5550,3 7993,7 8688,4 During heating -4495,7 644,2 -345,3 0 -13069,3 767,2 2300,4 5492,5 8687,6 During cooling -2823,2 -534,2 1388 0 -3154,8 978,9 2415,4 1724,7 0 Rest of time -752,4 -29,9 369,5 0 -1647,2 446,1 834,4 776,5 0,8
42
Table 4 Delivered Energy Retrofitting package one
Delivered Energy Meter Total, kWh Per m2, kWh/m2 Peak demand, kW Lighting, facility 7993,8 25,91 1,197 HVAC aux 629,2 2,04 0,07183 District cooling 0 0 0 District heating 14859,2 48,16 8,743 Equipment, tenant 5550,3 17,99 0,8 Total 29032,5 94,1 10,81183
Table 5 Delivered Energy Retrofitting package two
Delivered Energy Meter Total, kWh Per m2, kWh/m2 Peak demand, kW Lighting, facility 7994,4 25,91 1,197 HVAC aux 1322,4 4,286 0,1588 District cooling 355,6 1,152 1,573 District heating 7871,9 25,52 3,687 Equipment, tenant 5550,6 17,99 0,8 Total 23094,9 74,858 7,4158
Table 6 Energy Balance Retrofitting package two
Energy balance (sensible only)
Envelope & Thermal bridges, kWh Internal Walls and Masses, kWh Window & Solar, kWh Mech. supply air, kWh Infiltra-tion & Openings, kWh Occu-pants, kWh Equip-ment, kWh Lighting, kWh Local heating units, kWh Total -6017,4 -115,7 -687,4 -6968,5 -1337,1 1239,7 5550,7 7994,3 345,7 During heating -2084,8 857,4 -283,6 -870,3 -531,1 0 2,9 2562,3 345,8 During cooling -2842,4 -1314 -425,7 -5463,3 -691,7 1239,7 5427,5 4077,5 0 Rest of time -1090,2 340,9 21,9 -634,9 -114,3 0 120,3 1354,5 -0,1
