Analysis and optimization of building energy efficiency in Hammarby Sjöstad
ABOLFAZL SOUSANABADI FARAHANI MOHAMMADHASSAN MOHAMMADI
Analysis and optimization of building energy efficiency in Hammarby Sjöstad
By
ABOLFAZL SOUSANABADI FARAHANI MOHAMMADHASSAN MOHAMMADI
Thesis Submitted to the Department of Energy Technology, Royal Institute of Technology (KTH), in Fulfilment of the Requirement for the Degree of Master of Science
July 2013
LIST OF FIGURES ... 5
ABSTRACT ... 6
1. INTRODUCTION ... 7
1.1. OVERVIEW ... 7
1.2. HAMMARBY SJÖSTAD ... 7
1.2.1. Hammarby Model ... 8
1.2.2. Ventilation systems ... 10
1.3. OBJECTIVES ... 13
2. METHODOLOGY ... 14
2.1. OVERVIEW ... 14
2.2. DATA GATHERING AND DATA BASE CREATION ... 14
2.3. ENERGY MAPPING ... 16
2.4. PATTERN RECOGNITION ... 16
2.5. ENERGY INSPECTION ... 17
2.6. MEASUREMENT TECHNIQUES ... 17
2.7. BUILDING ENERGY SIMULATION ... 17
2.8. ANALYSIS RESULTS AND PRACTICAL PROPOSALS ... 18
3. RESULTS AND DISCUSSIONS ... 19
3.1. ENERGY MAPPING ... 19
3.2. PATTERN RECOGNITION ... 20
3.2.1. Specific energy consumption vs. Built year ... 20
3.2.2. Energy consumption vs. Byggherre ... 24
3.2.3. Byggherre (private & public) vs. Energy consumption ... 26
3.2.4. Technical Installation vs. Specific energy consumption ... 27
3.2.5. Electricity usage vs. Total specific energy consumption ... 29
3.2.6. OVK status vs. Specific energy consumption ... 30
3.3. INFRARED PHOTO (IR-‐PHOTOS) ... 31
3.3.1. Good case ... 32
3.3.2. Bad case ... 33
3.4. ENERGY INSPECTIONS ... 35
3.4.1. Unnecessary lighting ... 35
3.4.2. Pressure sensors ... 37
3.4.3. Temperature sensors ... 38
3.4.4. Lighting sensors ... 39
3.4.5. Frequency regulators ... 39
3.4.6. Filters ... 41
3.4.7. Fans ... 41
3.4.8. Inlets ... 41
3.4.9. Individual measurements ... 42
3.4.10. Operation and maintenance ... 42
3.4.11. Potential for development ... 43
3.4.12. Other observations and proposals ... 44
3.5. ENERGY AUDIT REPORTS AND RECOMMENDED SOLUTIONS ... 45
3.5.1. Report for BRF Hamnkranen ... 45
3.5.2. Report for BRF Sjöstadshamnen ... 46
3.5.3. Report for BRF Sjöresan ... 47
3.5.4. Report for BRF La Dolce Vita ... 49
3.5.5. Report for BRF Innanhavet 1 ... 49
3.5.6. Report for BRF Båtbyggaren ... 51
3.5.7. Report for BRF Älven ... 51
3.5.8. Report for BRF Hammarby Kaj ... 52
3.5.9. Report for BRF Farleden ... 52
3.5.10. Report for BRF Sickla kanal ... 53
3.5.11. Report for BRF Seglatsen ... 55
3.5.12. Report for BRF Sjöportalen ... 56
3.6. GOOD CASES VERSUS BAD CASES ... 56
3.7. MEASUREMENT TECHNIQUES ... 59
3.7.1. Fortum real–time information ... 59
3.7.2. Automatic meter reading system (AMR) ... 63
3.8. BUILDING ENERGY SIMULATION ... 64
3.8.1. Geometry ... 64
3.8.2. Individual effects on building energy performance ... 65
3.8.3. Conclusion ... 69
4. CONCLUSIONS AND RECOMMENDATIONS ... 70
4.1. CONCLUSIONS ... 70
4.2. RECOMMENDATIONS ... 72
BIBLIOGRAPHY ... 73
List of figures
Figure 1.1: Overview of Hammarby Sjöstad (Stockholms stad, 2008) ... 7
Figure 1.2: Hammarby model (Hammarby Sjöstad, 2013) ... 9
Figure 3.1: Energy mapping of Hammarby Sjöstad ... 19
Figure 3.2: Specific energy consumption vs. Built year ... 20
Figure 3.3: Specific energy consumption, Electricity usage vs. Built year ... 21
Figure 3.4: Number of buildings with no air treatment vs. Built year (Time periods) ... 22
Figure 3.5: Number of buildings with FTX system vs. Built year (Time periods) ... 23
Figure 3.6: Number of buildings with FVP system vs. Built year (Time periods) ... 23
Figure 3.7: Specific energy consumption vs. Byggherre, Dashed red lines represent buildings with FVP system installed ... 24
Figure 3.8: Specific energy consumption (heating only) vs. buildings with/without FVP system installed ... 25
Figure 3.9: Specific energy consumption (electricity only) vs. buildings with/without FVP system installed . 25 Figure 3.10: Specific energy consumption vs. buildings with/without FVP system installed ... 26
Figure 3.11: Specific energy consumption vs. Byggherre (Private & Public) ... 26
Figure 3.12: Effect of education in specific energy consumption (Familjebostader) ... 27
Figure 3.13: Average specific energy consumption for different types of ventilations systems ... 29
Figure 3.14: Percentage of electricity usage versus total specific energy consumption ... 30
Figure 3.15: OVK status versus specific energy consumption ... 31
Figure 3.16: Good case – building ... 32
Figure 3.17: Good case – Entrance ... 32
Figure 3.18: Good case – balcony door ... 33
Figure 3.19: Bad case – heat loss through windows and walls ... 34
Figure 3.20: Bad case – heat loss through poor insulation around the windows ... 34
Figure 3.21: Bad case – heat loss through windows and walls ... 34
Figure 3.22: Unnecessary lighting in garage ... 36
Figure 3.23: Unnecessary lighting in the building ... 36
Figure 3.24: Unnecessary lighting in town (Hammarby Sjöstad) ... 37
Figure 3.25: Pressure sensor (False installation) ... 37
Figure 3.26: Temperature sensor (ground surface sensor) ... 38
Figure 3.27: Temperature sensor in garage (false installation) ... 39
Figure 3.28: Lighting sensor (false installation) ... 39
Figure 3.29: Frequency regulator ... 40
Figure 3.30: Frequency regulator (Setting manual) ... 40
Figure 3.31: Dirty Filter ... 41
Figure 3.32: Clogged inlet ... 42
Figure 3.33: Wasting of hot water in a local restaurant ... 42
Figure 3.34: An example of technician visit timetable ... 43
Figure 3.35: Waste of heated air through vents on the roof ... 44
Figure 3.36: Best buildings versus worst buildings ... 57
Figure 3.37: Examples of windows in buildings with poor energy performance ... 58
Figure 3.38: Examples of windows in buildings with good energy performance ... 58
Figure 3.39: Energy account – real time data for electricity ... 60
Figure 3.40: Energy account – real time data for heating ... 60
Figure 3.41: Energy account – example of monthly data for heating ... 61
Figure 3.42: Energy account – daily electricity usage data, comparison between a sample day this year and the same day last year ... 62
Figure 3.43: Energy account – monthly heating data (comparison between year 2012 and 2013 ... 62
Figure 3.44: Specific energy consumption (only district heating) from Energy declaration vs. real-‐time data ... 63
Figure 3.45: Building layout ... 64
Figure 3.46: Building physical model ... 65
Figure 3.47: Glazing effect ... 66
Figure 3.48: Windows to wall ratio effect ... 67
Figure 3.49: Air tightness effect ... 68
Figure 3.50: Ventilation technique effect ... 69
Abstract
It is often considered that building performance in an operational phase is not as good as its designed performance. In fact, approximately 40% of the world’s total primary energy consumption is accounted existing buildings. Therefore, it would be of a great importance to analyze and optimize the existing buildings performance by taking total energy consumption and comfort situation into consideration. This is possible through measuring and analyzing the current building performance.
Hammarby Sjöstad is a high profile example of sustainable city development which has been chosen as a case study in this research project because most of the operational buildings located there have not reached their projected efficiency during the design phase. Therefore, the main objective of this research study is to investigate this problem and formulate cost-‐effective, high performance solutions in order to increase the overall efficiency of the buildings in Hammarby area. In this study a “Case Study” methodology has been performed with literature studies, in-‐depth interviews, seminars and gathering of quantitative data, concerning the operational goals of the environmental program of Hammarby Sjöstad.
To gather the required data, meetings with different organizations were scheduled.
More than 15 important parameters were gathered for more than 100 buildings in Hammarby Sjöstad.
Going through all the data, some relations were discovered which led to interesting yet simple solutions for the low energy efficiency of the buildings in the area. Patterns were recognized however they had to be evaluated and their accuracy had to be tested.
Moreover, to further evaluate the performance of the buildings, Energy audits were done with the help of an energy expert. The aforementioned buildings were visited and their performance was checked in detail to further prove the pattern results. Different parameters were considered during the visits including the architecture, technical installations and maintenance. Meanwhile, by taking advantage of the DesignBuilder software, a number of simulations were performed in order to further examine the previous findings. Finally, some practical recommendations and also conclusions are presented.
Keywords: Energy efficiency, building energy performance , sustainable energy, Optimization, Smart city, Green building, Ventilation technique, Energy audits, Energy simulation
1. Introduction
1.1. Overview
Existing buildings account for approximately 40% of the world’s total primary energy consumption and 24% of the world’s CO2 emissions, according to the International Energy Agency, (IEA, 2006).
There is a great opportunity in real estate sector to make significant reductions in energy consumption, therefore reducing the need for supply and end-‐use energy costs.
It is therefore essential to introduce effective energy efficiency measures in the built environment if governments and business tend to successfully address energy security and ambitious carbon reduction targets.
On the other hand, rising energy costs encourage households and businesses to reduce their energy consumption rate. It is evident now that ‘greener’, more energy efficient buildings are more valuable in the property market than conventional buildings, which increases the commercial incentive to invest in properties with improved sustainability performance.
1.2. Hammarby Sjöstad
Hammarby Sjöstad is a high profile example of sustainable city development located on both side of lake Hammarby sjö, bordering Nacka Municipality to the east. An overview highlighted picture of this area taken by Stockholms stad in 2008 is represented below in Fig. 1.1.
Figure 1.1: Overview of Hammarby Sjöstad (Stockholms stad, 2008)
The city of Stockholm has high ambitions for environmental issues and sustainable development. New areas are planned or in developing process and the most valuable input for these projects would be the experience from environmental profile of Hammarby Sjöstad. In Hammarby Sjöstad, the goal has been to implement the environmental profile in the urban district, both internally and externally, in order to create a sustainable residential environment.
The development of the area has not interfered with the people life style, as there are many residential buildings, several workplaces and business properties already in use.
The overall goal for Hammarby Sjöstad project was set on 50% lower environmental impact comparing to the early 1990s. (Sofie Pandis Iverot, 2011)
The most noticeable reduction in energy consumption and environmental impact was expected to happen within the buildings in the operational phase. A huge save was expected in in the amount of heating demand and drinking water. The reason behind this expected outcome was the effort and investment of developers in order to save energy by using extra insulation, energy efficient windows, proper ventilation, electrically efficient installations, lighting control and so on. Some buildings have installed heat pumps in the exhaust air to recover heat.
Also, choice of eco-‐friendly building products and materials, proper fittings with reduced water flow and low-‐flush toilets have helped with regard to indoor air quality, water and sewage control.
According to previous study (Brick, 2008), the percentage of car journeys has been decreased, while the number of journeys using Tvärbanan and the ferry, have increased in comparison with 1990s level.
1.2.1. Hammarby Model
Everyone in Hammarby Sjöstad is a part of an eco-‐cycle. The eco-‐cycle solution in Hammarby Sjöstad is called the Hammarby Model. In this model transportation systems, waste management, water treatment and energy production are considered as key parameters toward sustainability.
The Hammarby model has been developed jointly by Stockholm Water Company, Fortum and Stockholm Waste Management Administration.
There are many eco-‐city models being developed in the world today however, smart interaction of different sustainable technologies in Hammarby model makes it a unique example among others. (Figure 1.2)
Figure 1.2: Hammarby model (Hammarby Sjöstad, 2013)
The Hammarby model is recognized by its unique interaction among three main parameters; Energy, Waste and Water. A brief description for each part is given below.
1.2.1.1. Energy
According to Hammarby model, the residents are supposed to produce half the amount of energy they need. This can be achieved by e.g. reusing the heat from the purified wastewater, and by utilizing the energy from the combustible household waste, which has been separated at source.
1.2.1.2. Waste
Waste management in Hammarby area is a well-‐developed system, where with collaboration of residents, waste is being separated at source, which will lead to reduced amount of waste transports in the area.
In courtyard chutes, the residents can leave combustible household waste and food waste at a certain spot with separate intakes. The waste is collected via an automated underground pneumatic system. Other type of waste, such as paper, metal, glass, bulky waste and plastic packaging material is collected in block-‐based recycling rooms.
Hazardous waste, such as varnish, paint, nail polish, solvents and cleaning agents are collected at area-‐based hazardous waste collection points.
1.2.1.3. Water and sewage
• The natural cycle of water in Hammarby Sjöstad
The collected water from lake Mälaren is purified in Norsborg water treatment plant up to drinking purification level. The treated water is then sent through pipes to residents in Hammarby area and is used for e.g. cooking, drinking, washing, showering and flushing toilets. This water after being used becomes sewage, which is then sent to Henriksdal’s wastewater treatment plant to be treated by mechanical, chemical and biological means.
• District heating and cooling
District heating in Hammarby Sjöstad is a part of a larger Stockholm district heating grid. In Hammarby Sjöstad, before the purified wastewater is released into the Baltic Sea, it is pumped to Hammarby District Heating plant. In district heating plant the energy in the water, in form of heat, is being extracted by taking advantage of heat pumps. This heat is further used for district heating purposes. The cold water produced in the process, is used for district cooling of the area.
• Biogas
About 1000 apartments in Hammarby area have biogas cookers. This biogas is the byproduct of sludge, from wastewater treatment, digestion. Interestingly, the biogas
"produced" from the waste product of an average family in Hammarby area, is almost equal to the amount of biogas they use for cooking. The use of biogas-‐powered cookers in Hammarby area has resulted in 20 percent lower electricity consumption.
(Hammarby Sjöstad, 2013)
1.2.2. Ventilation systems
A lack of proper ventilation can cause too much humidity, condensation, overheating and creation of odors, smokes and pollutants. Ventilation is a part of HVAC (heating, ventilation and air-‐conditioning) system, which is very energy intensive, usually including of large fans, air-‐conditioning and heating components.
Therefore it is also of much importance for this area to consider proper type of ventilation system with cost effective low energy consumption rate. Proper ventilation should be continuously monitored and that is why the house must be provided with a ventilation system. Below, brief descriptions of different techniques being used in Hammarby Sjöstad are given.
Five different methods of ventilation are as follows:
• S = Natural ventilation (Självdrag)
• F= Mechanical exhaust air system (Mekaniskt frånluftsystem)
• FT = Mechanical exhaust and supply air system (Till-‐ och Frånluftsystem)
• FTX = Mechanical exhaust and supply air system with heat recovery (Från-‐ och tilluftsventilation med värmeåtervinning)
• FVP = Exhaust air heat pump (Frånluft värmepump) 1.2.2.1. Natural ventilation (Självdrag)
This ventilation system is the most commonly used system in private buildings. Natural ventilation system is usually found in older type of buildings where the air naturally enters through running, leaks and sometimes through special windows. This system works poorly in the summer and provides overall uneven ventilation. Modern houses are too tight and not suitable for natural ventilation. Besides, the air coming into the house is not filtered which can cause problem for the tenants.
• Advantage of Natural ventilation
− It is inexpensive to install
− It is maintenance-‐free (doesn’t require regular maintenance)
• Disadvantages of Natural ventilation
− It is extremely weather dependent
− It doesn’t provide a proper thermal comfort
− It is difficult to control supply air
1.2.2.2. Mechanical exhaust air or extraction system (Mekaniskt frånluftsystem)
It is a common type of ventilation in houses today. The basis is to "pull" the air through the house and creating negative pressure. A centrally located fan sucks the air continuously in moderation. The fan can be mounted on different places such as roof or stove hood.
Controlling the flow is done either by a separate speed control or stove hood controls.
Supply air/fresh air enters through the vent in the living areas or grilles in windows. Fresh air is taken in the same way as in “S” system and the inconveniency of the unfiltered air remains.
• Advantages of Mechanical exhaust air
− It often provides good ventilation
− It is rather inexpensive to install
• Disadvantages of Mechanical exhaust air
− Ventilation can be noisy
− Operating expenses are high
− There is often little or no recovery
− It is difficult to control the supply air
1.2.2.3. Mechanical exhaust and supply air system (Till -‐ och Frånluftsystem)
It is an unusual way of ventilation, which is not allowed nowadays in new constructions. The basic principle of ventilation is to take in the fresh air (supply)
through clean spaces such as bedrooms and living room while taking out the used air (exhaust) through the kitchen and bathroom. In systems with controlled airflow can have both supply and exhaust air in the same room. (energimyndigheten, 2013)
• Advantage of Mechanical exhaust and supply air system
− It provides very good and controlled indoor air.
• Disadvantages of Mechanical exhaust and supply air system
− It is quite expensive to install
− Ventilation can be noisy
− Operating expenses are high
− There is no recovery
1.2.2.4. Mechanical exhaust and supply air system with heat recovery (Från -‐ och tilluftsventilation med värmeåtervinning)
This technique is very similar to FT ventilation system. A heat exchanger in the air-‐
handling unit recycles the heat from the exhaust air to preheat the supply air before entering the building. This technique can potentially recover about 30-‐60% of the exhaust heat.
Fans can be mounted to the attic, roof or adjacent to the hood. Controlling the flow is done either with a separate speed control or with stove hood controls.
• Advantages of Mechanical exhaust and supply air system with heat recovery
− Recycling heat from exhaust air results in a higher efficiency
− It provides good air quality thanks to controlled supply and exhaust air
• Disadvantages of Mechanical exhaust and supply air system with heat recovery
− It is expensive to install
− Operating expenses are high (It requires more maintenance than other systems)
− Ventilation can be noisy. (There is some risk of noise if the unit is not installed properly)
1.2.2.5. Exhaust air heat pump (Frånluft värmepump)
The apparent efficiency or coefficient of performance (COP) of a heat pump can reach up to 500%. The working principle of a heat pump is basically the same as in a refrigerator.
Exhaust air heat pump recovers heat from the ventilation system exhaust air.
Afterward, The recovered energy will be transferred through a heat exchanger in air handling unit thus warming the fresh air. The exhaust air heat pump can be used for water heating during the hot season when the fresh air does not need to be pre-‐heated.
• Advantages of exhaust air heat pump (FVP):
− The installation is relatively easy, especially for the buildings with F-‐type of ventilation system
− It is a complete package that can provide heat, hot water, ventilation and heat recovery
− In comparison to FTX, more heat can be extracted by this method. In fact, the amount of heat is limited to the sensible heat in the ventilated air which means that it corresponds to the energy extracted when the air is cooled and dehumidified from 20C to the ambient temperature
• Disadvantage of exhaust air heat pump (FVP):
− It is expensive to install for old buildings with natural ventilation system since a duct system is required to be built
1.3. Objectives
A number of evaluations and research projects have been performed focusing on different aspects of sustainable development of Hammarby Sjöstad. Hellström conducted a research with a focus on Hammarby model (Hellström, 2005), Engberg and Svane worked on the implementation of the Environmental strategy (Engberg, 2007) and the evaluation of environmental profile of Hammarby Sjöstad was investigated by the department of industrial ecology at KTH (Sofie Pandis Iverot, 2011). However, despite the great effort regarding the reduction of energy consumption in real estate sector in Hammarby Sjöstad, most of the buildings have not reached the projected efficiency during the design phase.
Therefore, the main objective of this research study is to investigate this problem and formulate cost-‐effective, high performance solutions in order to increase the overall efficiency of the buildings in Hammarby area. In this study a “Case Study” methodology has been performed with literature studies, in-‐depth interviews, seminars and gathering of quantitative data, concerning the operational goals of the environmental program of Hammarby Sjöstad.
To gather the required data, meetings with different organizations were scheduled.
More than 15 important parameters were gathered for more than 100 buildings in Hammarby Sjöstad. Going through all the data, some relations were discovered which led to interesting yet simple reasons for the low energy efficiency of the buildings in the area. Patterns were recognized however they had to be evaluated and their accuracy had to be tested. To have a better sense of the problem and to further evaluate the performance of the buildings, Energy audits were done with the help of an energy expert, Willy Ociansson, for 12 selected BRFs. The aforementioned buildings were visited and their performance was checked in detail to further prove the pattern results.
Different parameters were considered during the visits including the architecture, technical installations and maintenance. Meanwhile, by taking advantage of the DesignBuilder software, a number of simulations were performed in order to further examine the previous findings.
2. Methodology
2.1. Overview
To achieve the objectives of this study the research process was structured within seven different phases as follows:
• Data gathering and database creation
• Energy mapping
• Pattern recognition
• Energy inspection
• Measurement techniques
• Building energy simulation
• Result analysis and presenting practical proposals
2.2. Data gathering and data base creation
In this stage of the study, literature studies were carried out in order to get an overall view and a better understanding about the problem. Considering the involvement of HS2020/Energi in initiation of this project, the baseline for low energy consumption goal was set at 100 kWh/(m2.year) for the existing buildings in Hammarby Sjöstad.
Therefore, creating a database for more than one hundred buildings to illustrate the current situation in energy consumption seemed to be a fundamental need to begin the project.
Database generation has begun based on a primary excel sheet received from the Stockholm county environmental administration (Stockholmsstad Miljöförvaltningen).
The database was categorized based on known priorities and different parameters were chosen by the board members of the HS2020/Energi to be included in the database.
These parameters are as follows:
• Energy declaration date
• Building’s built year
• Address
• Location on the map
• Owner
• Tenant owner’s association (BRF or bostadsrättsföreningar)
• Membership in Hammarby Sjöstad local association (Medlemskap i sjöstadsföreningen)
• Name of property (Fastighetsbeteckning)
• Constructor (Byggherre, “The organization initiating the construction, the owner”)
• Architect company
• Entrepreneur
• Atemp, m2 (Areas that are intended to be heated to over 10 degrees Celsius)
• BOA, m2 (Boarea, The living space together with the auxiliary areas building floor space)
• LOA, m2 (Area of the premises including garage)
• Number of apartments in the building
• Number of stairways
• Specific Energy Consumption, kWh/(m2.year)
• Share of electricity usage in Specific Energy Consumption, kWh/(m2.year)
• Ventilation system type
• OVK status (Mandatory ventilation control)
• Visited buildings (This refers to the buildings which have been visited by the energy expert during the preparation of energy declaration)
• Avgift (fee per Square meter: This is a monthly fee which will cover the common costs, such as property maintenance, repairs, heating, garbage collection, administration, and the association's expense. This fee normally must be paid no later than the last working day before the new month begins)
• Maintenance company (Driftfirma)
• Technical Installation
• Comments and additional information
Considering the importance, availability and time, different meetings and interviews were scheduled, questionnaires were sent via email or telephone conversations and energy declaration documents beside some dated maps were fetched from Stockholm energy centrum.
Some of the data resources include:
• Boverket (Energy declarations)
• Stockholms stad (Energy and environment department)
• BRFs (bostadsrättsföreningar or condominium associations)
• Sjöstadsföreningen (Hammarby Sjöstad local association)
• Fortum
• Riksbyggen
• KTH
• Glashus Ett
• Other sources
Database generation happened to be the most time consuming and complicated phase of this project. The list below shows different type of questions in the questionnaire, which has been used in the meetings and interviews with condominium associations (BRF’s) based on priorities of HS2020/Energi. Some of the main questions include:
• Who are the “Byggherre/Entreprenör/Arkitekt” of this building
• Who is/was responsible for maintenance and which type of contract do you have with them? When is/was the expiry date of this contract? Any contact person for future follow-‐up? (Avtal med vilken driftfirma? Avtalet löper ut när?
Kontaktperson?)
• Does BRF own the flats or is it a “renting out” type (Allmännyttig/hyresrätt eller BRF?)
• How is the monthly Fee per m2 (Avgift per kvm)?
• Technical installations
• Is garage heated (Värmda garage)
• Is there electricity heating in downpipes (Elvärme i stuprör)
• Is there individual hot water measurement? (Individuell mätning av värme-‐
varmvatten)
• How is the remaining guaranty time (Kvarstående garantiärenden)
In conclusion, some factors were chosen as “General Factor” which were collected for all of the buildings and were further used in Energy Mapping and Pattern Recognition phase. Other factors, has been considered as “Special Factors” which has been gathered more in detail for Energy Inspection phase and have been used in Pattern Recognition, Building Energy Simulation and also Presenting Practical Proposal.
2.3. Energy mapping
A basic energy map of Hamarby Sjöstad was created previously however, the new database made it possible to have a more detailed and more precise mapping solution for the area. The purpose of this phase has been to provide sufficient data for energy consumption visualization. Some practical issues have been discussed about the real time visualization.
Regarding the real time visualization, considering the previous mapping by “Mikael Östling” and also meeting Greencon Company, it has been concluded that there are not enough means to finance real time visualization at this stage.
2.4. Pattern recognition
The comprehensive database has made it possible to perform a proper and up to date energy mapping. Furthermore, this huge source of data has been utilized in order to search, discover, discuss and analyze some patterns among the existing buildings in Hammarby Sjöstad and derive conclusions to detect unseen problems and come up with proposals to reduce or eliminate the negative effect and even in some cases, practical solutions are suggested.
The investigated patterns are presented as follows:
• Energy consumption versus building’s built year
• Electricity consumption versus building’s built year
• Energy consumption versus Byggherre1
• Privat & Allmännyttan versus Energy Consumption
• Ventilation type versus specific energy consumption (Teknisk installation -‐ Specifik energianvändning)
• Electricity usage versus total energy consumption (El användning -‐ Totalt energiförbrukning)
• OVK (Mandatory Ventilation Control) status versus specific energy consumption (OVK status -‐ Specifik energianvändning)
• IR-‐photos
Each pattern will be explained and discussed in detail in the results and discussion part of this report.
2.5. Energy inspection
Twelve different condominium associations (bostadsrättsföreningar or BRFs) have been visited one by one and inspected in collaboration with Willy Ociansson, the award winning energy expert in energy efficiency from Karlstad. An abstract report with the most important headlines of the inspection results has been prepared and sent out to each condominium association (BRF) to indicate general and special deficiencies and help them to obtain a better understanding of the situation and give them the possibility of planning to take relevant action to tackle (at least some of those) problems. The detailed results together with proposals for lowering the energy consumption and improve indoor climate will be presented in the results and discussion part.
2.6. Measurement techniques
The different measurement techniques have been studied. Moreover, the available measurement instruments in technical installations have been investigated. Considering the importance of access to real time data, a considerable amount of time have been spent on searching for the best way to get hold of such data. The findings will be presented in the results and discussion section.
Furthermore, the placement of the measuring instruments according to their relevant functions has been assessed during the energy inspections. Possible adjustments and/or replacement are presented in the proposal phase.
2.7. Building energy simulation
Currently, many different factors should be taken into consideration and balanced accordingly to provide well-‐functioned, comfortable and good quality buildings.
Besides, buildings must comply with building regulations, the environmental impacts must be reduced and the current energy systems should be optimized in order to decrease the energy consumption (and consequently energy costs).
To accomplish the goal of this study and complete the framework, a sample building has been modeled with building performance analysis software called DesignBuilder. This software is acknowledged as the most comprehensive interface to the state of the art EnergyPlus building simulator. (DesignBuilder)
A number of parameters such as building type, windows size, glazing type, etc. were assumed in the simulation to be able to perform a comparison of different building designs and their performance. The results will be illustrated and discussed in detail in results and discussion section.
2.8. Analysis results and practical proposals
At last, the results of all the previously mentioned phases were presented, discussed and analyzed. Finally, considering different assessment methods, evaluations overall understanding of the situation, some practical proposals are provided for different cases in order to reduce (and in some cases minimize) the total energy consumption.
3. Results and Discussions
3.1. Energy mapping
Energy mapping helps with providing municipalities, researchers and utilities a simple way to evaluate existing energy use in a community and plan to improve energy efficiency by means of utilizing better building standards and alternative energy resources.
The mapping process represents the idea that maximizing the energy efficiency in Hammarby area requires planning to go beyond integration of transportation issues, improvements in the built environment and orientation of the buildings but making sure that unavoidable energy needs are met in the most effective way, such as obtaining the highest and best use from a given primary-‐energy resource.
Inputs to energy mapping can potentially maximize the amount of energy savings and greenhouse gas (GHG) emissions reduction. The mapping itself is the means by which these enhancements are communicated to researchers, decision makers and end users.
To maintain the economic attractiveness and competitiveness of a community, a futuristic municipal long term planning for maintaining and encouraging access to secure, affordable sources of energy is required.
Figure 3.1: Energy mapping of Hammarby Sjöstad
Considering the positive aspects of energy mapping process and based on a primary database, a basic visualization map was designed (Fig. 3.1) to illustrate the purpose of energy mapping in Hammarby area. With completion of this study, the newly generated comprehensive database has made it possible for the design group to prepare a more detailed and precise mapping solution for HS2020 project.
In this study, the purpose of this phase has been to provide sufficient data for energy consumption visualization and some practical issues have been discussed about the real time visualization. In this map, users will be able to find details of real time, monthly and annual energy consumption data for individual buildings across the Hammarby area derived from statistical data and broken down into specific energy uses like electricity and district heating.
The red blocks represent the buildings with the highest specific energy consumption and the green blocks represent the buildings with the best (i.e. lowest) specific energy consumption. The other colors represent the buildings with the specific energy consumption in between.
3.2. Pattern Recognition
3.2.1. Specific energy consumption vs. Built year
As it is shown in the figure below (Fig. 3.2), buildings in Hammarby Sjöstad, which are considered in this study, were built during a 60 years period from 1944 till 2012.
However, the vast majority of these buildings were built in a 15 years period from 1997 to 2012 as illustrated in the figure below.
Figure 3.2: Specific energy consumption vs. Built year
Red bars in the figure represent the specific energy consumption (only district heating) and the black horizontal line represents the 100 kWh/(m2.year) goal of HS2020/Energi project. Considering the technology development, environmental goals and increased public awareness, one would expect the energy consumption in the buildings to be decreased during this period of time. However, as it's shown in the figure, there is no notable change in specific energy consumption from 1944 to 2012.
In the next figure (Fig. 3.3), the amount of energy as electricity2 from total specific energy is shown in the same period of time (blue bars). In this figure once again the red bars represent the specific energy consumption (only district heating). Once again, by introduction of efficient electrical instruments, appliances, lamps and etc., the electricity consumption could have been decreased; however the figure represents no special trend.
Figure 3.3: Specific energy consumption, Electricity usage vs. Built year
Several parameters have been considered in this study to find out about the reasons behind the high rate of energy consumption in new buildings.
Most of the considered parameters are set into two different categories as follows:
• Architecture
• Energy efficient installation
3.2.1.1. Architecture
After the energy crisis of the 1970's, an entirely different building design approach began to take hold toward saving energy. Small windows along with tight building envelope resulted in lower energy consumption comparing to past 1970s.
Buildings were sealed without thought of the importance of fresh air and proper ventilation. The new, tight, energy efficient buildings did not perform properly in ventilating the indoor pollutants, thereby creating a whole host of problems. Also, hidden moisture problems due to tight construction began to surface, which were leading to an increasing incidence of mold growth and related health problems. (Center of desease control and prevention, 2013)
Tight, energy efficient construction to save energy is an excellent idea, so is the fresh air and no interior moisture problems. Attention has to be focused on the importance of good indoor air quality and its effect on health. Good building practices and proper
2 It is only the external electricity usage of the building that is considered here. The individual electricity usage of each apartment is NOT included.
