Nowadays, buildings are responsible for the 40% of energy consumption in the European Union, with energy up to 68% being coherent with thermal loads. Acknowledging the great potential of building sector, a substantial amount of the current building inventory must be refurbished, based on the trade-offs between energy and thermal comfort. To this effect, this study investigates the impact of retrofitting measures in residential envelope for areas experience Mediterranean climate. Seven detached houses, located in Cyprus, were modelled, investigating 253 parameters of envelope interventions and also, 7,056 combinations of these measures. In general, the findings revealed a seasonal performance variation of interventions with regards to the outdoor climate. The application of roof insulation determined as the most economic viable solution during retrofitting (single interventions), achieving a reduction up to 25% of annual energy consumption with enhancement of the indoor thermal environment. In the perspective of synergies between interventions, the application of roof and external walls thermal insulation with upgrade of glazing system with double Low-E demonstrated exemplary levels of performance decreasing on average energy consumption up to 38%.The findings of this research will contribute on the development of guidelines for designers and house builders for a perceptual retrofitting of existing residential envelopes in Cyprus and also, for countries experiencing the Mediterranean climate.

Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SEK. The aim of this project is reducing the amount of the electricity and heat invoice promoting smart energy improvements. The improvements proposals can be divided in three sections; energy savings of the changing rooms, efficiency increase of the compressors and dehumidifier energy savings. For heat the tap water and the changing room’s ventilation it is suggested to take profit from the heat released at the condenser and so reduce its heat load requirements. For this proposal two different configurations are studied. In order to increase the efficiency of the compressors the possibility of reducing the condenser temperature will be studied. Three proposals will be studied to carry out this commitment; Installing a condensing temperature control, installing a evaporate cooler and having a snow storage. Finally, one of the largest consumers of electricity in Kastvallen ice hockey rink is the dehumidifier. The current dehumidifier works with a desiccant wheel. The desiccant material extract the moisture from the processed air flow, after that the desiccant has to be reactivated with ‘fresh air’. This reactivation air needs to be heated 95ºC, so the waste air released after the reactivation of the desiccant is air at high temperature. The first proposal is preheat the reactivation air with the hot waste air in order to reduce the heating requirements, conducting this proposal the total money saved each year would be 41811 SEK with a Pay-back around 1 year. The second step is studied the possibility of heating the air with district heating, taking into account that district heating is three times cheaper than electricity, conducting this proposal the total money saved each year would be 45629 SEK with a Pay-back around 1 year. The last proposal is to combine preheating and heating with district heating, conducting this proposal the total money saved each year would be 61553 SEK with a Pay-back around 1.6 years. All the previous energy improvements proposals are studied with empirical and analytical methods and using the knowledge gained during the previous years of studies. The study concludes that the best proposal for the dehumidifier is combine the preheating and heating with district heating. In addition of the money saved, this measure allows to save 2.71 Tm of CO2 each year. For the refrigeration cycle, the study concludes that installing a controlled temperature control is the best option if the price of that is lower than 334726 SEK. If not the best option is heating the rooms and the ventilation with the condenser of the refrigeration cycle. These measures could reduce between 8% and 20% of the total energy invoice plus a considerable reduction of CO2 emissions. Evaporative cooling and snow storage would be studying after with the data of the first year of the condensing temperature control; if it is installed.

Med det rådande klimathotet ställs högre krav på fastighetsbranschen att minska sin energianvändning. Denna rapport fokuserar på energieffektivisering i KTHs, Kungliga Tekniska Högskolans, huvudbyggnad som förvaltas av Akademiska Hus. Huset, som är en av KTHs minst energieffektiva hus, är byggt i nationalromantisk byggstil och invigdes 1917. Idag klassificeras byggnaden som en blå byggnad, enligt Stockholms Stadsmuseum, vilket är deras högsta klassificering och betyder att den har ett högt historiskt värde. Denna rapport studerar och utvärderar de energibesparingsåtgärder som Akademiska Hus har genomfört i huvudbyggnaden sedan 2016. Ytterligare studeras andra energieffektiviseringsåtgärder i andra hus med kulturhistoriska värden. En undersökning över befintliga tekniker och metoder för energieffektivisering redovisas även i rapporten. Resultatet visar att många energibesparingsåtgärder har genomförts i huset och lett till förbättring men denna förbättring motsvarar inte Akademiska Hus mål om en energiminskning på minst 3 % per år. Det finns nya tekniker som kan implementeras i olika delar av huset för att minska energianvändningen utan att påverka det kulturhistoriska värdet. En av dessa tekniker är att optimera styrning av värme- och kylsystemet. / With the current climate threat, higher demands are placed on the real estate industry to reduce its energy use. This report focuses on the energy efficiency in KTH's, Royal Institute of Technology’s, main building, which is managed by Akademiska Hus. The building, which is one of KTH's least energy-efficient buildings, is built in a national romantic building style and opened in 1917. Today, the building is classified as a blue building, according to the Stockholm City Museum, which is their highest classification and means that it has a high cultural-historical value. This report studies and evaluates the energy saving measures that Akademiska Hus has implemented in the main building since 2016. Furthermore, energy saving measures are being studied in other houses with cultural-historical values. A study of other technologies and methods for energy conservation has also been done in the report. The results shows that many energy saving measures have been implemented in the main building and have led to improvement, but this improvement does not meet Akademiska Hus's goal of an energy reduction of at least 3 % per year. There are new technologies that can be implemented in different parts of the building to reduce the energy used. One of these methods is the optimization of heating and cooling system.​

Low-emissivity (low-E) window films are designed to improve the energy performance of windows and prevent indoor overheating by solar radiation. These films can be applied to different types of glazing units without the need for changing the whole window. This characteristic offers the possibility to improve the energy performance of the window of old and historic buildings for which preservation regulations say windows should remain more or less unchanged. This research aims to figure out to what extent a low-E window film can improve thermal comfort and energy performance of an old three-storey historic stone building in the cold climate of Mid-Sweden. In this research, first, with help of the simulation software “IDA ICE”, the entire building was modelled without window films in a one-year simulation. Second step was to add the low-E window films (3M Thinsulate Climate Control 75 (CC75)) to all the windows and repeat the simulation. Comparison between the results of the two cases revealed an improvement in energy use reduction as well as the thermal comfort when applying the films. For the application of the window films, a cost analysis using payback method was carried out which showed a long- time payback period. Although an investment with a long-time payback period is considered as a disadvantage, for historic buildings with very strict retrofit regulations specially when it comes to the building’s facades, application of the low-emissivity window films for better energy performance and thermal comfort is among the recommendable measures, but not necessarily the best.

The thesis focuses on energy savings of an apartment building. Firstly, the basic terms concerning apartment building and their costs are explained. Secondly, the thesis looks into energy efficiency of buildings, possibilities of energy savings and methods of economic evaluation of investments. The thesis sets the goal to evaluate current state of a selected apartment building from the perspective of energy efficiency and to propose possible energy saving measures. Lastly, the thesis aims to evaluate proposed measures from economic perspective and the perspective of energy efficiency.

The issue of energy saving building is a current topic of today. The increasing costs of operating buildings reduce economic efficiency of the organization operations. A large part of the operating cost is energy cost. An effective tool for improving the energy performance of buildings is an EPC method. The implementation of energy projects through EPC is offered by Energy Services Company. This thesis evaluates the economic efficiency of the project implemented by the EPC and analyses its risk factors. The subject of EPC project is modernisation of an energy sector of a hospital building. The economic efficiency of the project is interpreted on the basis of economic indicators Net Present Value, Internal Rate of Return and Profitability Index. There was also performed Monte Carlo simulation supported by Oracle Crystal Ball software within the analysis of risk factors for the project.

The aim of the thesis is the energy rating of buildings. The introduction included the issues of the topic, including normative and legislative regulations, process energy performance certificates along with energy audits for residential building. The object is evaluated in terms of energy, economic and environmental. Within the energy audit was designed and evaluated austerity measures.

Energy supply in Sweden year 2011 amounted to 577 TWh. The final energy consumption for industrial, residential and service was 379 TWh. Sweden has energy policy goals to reduce energy use in buildings. One of these goals is to reduce the energy use by 20 % in 2020 compared to the year 1995. An important step to achieve this goal is to target energy efficiency measures in existing buildings. There are also financial incentives to implement energy efficiency measures due to the fact that the cost of energy represents 30-40% of a buildings maintenance costs. In general, up to 20 % of the energy consumption can be reduced without major reconstruction. In this master thesis project presented here, an energy audit was performed and energy efficiency measures was proposed for an existing building located at Järfälla, Stockholm. The property belongs to SAAB - Defence and Security. They have an internal target to reduce energy use in their buildings with 50 % by 2015 compared to 2009. The work of this master thesis project was limited to a building locally termed hus A. This part of the property is the oldest and was built in 1968, but has expanded gradually to the year 1977. Hus A contains of offices, a production hall, laboratories and storage areas. The energy audit showed that the electricity use is far greater in hus A, compared to the an average office and administration building. This is mainly due to production processes. A breakdown of the highest electricity consumers are: Industrial processes – 61.9 kWh/m2/year Lighting – 35.7 kWh/m2/year Fans – 33.2 kWh/m2/year Refrigeration – 21.8 kWh/m2/year Compressed air – 18.9 kWh/m2/year Computer units – 7.8 kWh/m2/year Frequency converters – 4.4 kWh/m2/year Waste heat from industrial processes, primarily from the production hall leads to high cooling demand to maintain good thermal comfort. Limitations in operation control of the buildings HVAC (Heating, Cooling and Air-conditioning) systems causes high heating and cooling demand and hence the buildings thermal mass is not properly utilized. Energy saving measures was mainly focused on increasing the controlling capability of HVAC systems. By implementing the energy efficiency measures presented in this master thesis report, building thermal mass will be more efficiently utilized. In addition, end use of electricity, heat and cooling will be reduced. In total, seven energy-saving measures proposed.  One measure is implemented to prevent heating and cooling at the same time. A brief description of the energy efficiency measures and the expected result is found below. Adjust set point for TAFA301 Energy saving: 94.0 MWh/yearPayback time: 0 year Establish time schedule for compressed air systemEnergy saving: 110.8 MWh/yearPayback time: 2.5 months Demand controlled temperature set point to heating systemEnergy saving: 167.0 MWh/yearPayback time: 3.5 months Demand control of airflow in the production hallEnergy saving: 155,5 MWh/yearPayback time: 2 years and 10 months Establish time schedule for frequency invertersEnergy saving: 104.0 MWh/yearPayback time: 3 years and 2 months Radiator thermostats to the first part of the production hall Energy saving: 6.5 MWh/yearPayback time: 5 years and 2 months Demand control of airflow in conference roomsEnergy saving: 11.0 MWh/yearPayback time: 12 years and 2 months

This paper examines the nature and characteristics of the introduction of energy-saving measures, formulates the basic concepts, goals for energy conservation, and also presents and compares the methods for assessing the economic efficiency of energy-saving measures in Russian research practice. The dynamics of energy prices in the Sverdlovsk region for enterprises are presented, a comparative analysis of price changes in this area and in the lending area has been conducted, also an empirical research was conducted to define which methodologies and indicators are used practically in the course of calculating the assessment of the effectiveness of introducing energy-saving projects. The proposed by us improvement of efficiency evaluation of introducing energy saving measures is presented. The approbation of the developed improvement also are presented. / В данной работе рассматривается сущность и особенности внедрения энергосберегающих мероприятий, формулируются основные понятия, цели, по энергосбережению, а также приводятся и сравниваются методики оценки экономической эффективности энергосберегающих мероприятий в российской научно-исследовательской практике. Приведена динамика цен на энергоносители в Свердловской области для предприятий, проведен сравнительный анализ изменения цен в данной сфере и в сфере кредитования, а также было проведено эмпирическое исследование по определению того, какие методики, показатели используются на практике при расчете оценки эффективности внедрения энергосберегающих проектов. Представлено предлагаемое нами совершенствование оценки эффективности внедрения энергосберегающих. Также представлена апробация разработанного совершенствования.

En stor del av alla bostäder som byggdes mellan 1965-1974 brukar betecknas miljonprogrammet. Efter 40-50 års förbrukning har byggnaderna uppnått sin tekniska livslängd och är därför i behov av renovering. Detta samtidigt som bostadsbristen återstår och energikraven från myndigheter blir allt strängare i syfte att reducera bostadssektorns energianvändning samt för att uppnå ett hållbart samhälle.  Studien är baserad på ett flerbostadshus, Barytongatan 4 som är belägen i Göteborg och som är en del av projektet Kaverös etapp II. I denna studie undersöks energibesparingsåtgärder i samband med våningspåbyggnad och de regelverk som gäller vid om- och tillbyggnad enligt BBR och PBL. I simuleringsprogrammet IDA ICE kunde olika energibesparingsåtgärder studeras. Resultatet från varje enskild åtgärd och en sammansättning av dessa jämfördes därefter med den befintliga byggnadens energideklaration och statisk. Studien är koncentrerad till energisimuleringar och behandlar inga ekonomiska beräkningar. Rapporten fastställer att en våningspåbyggnad, som ökar byggnadsvolymen, är en tillbyggnad samt att allt för stora åtgärder i en befintlig byggnad klassas som en ombyggnad enligt BBR och PBL. Studien berör energibesparingsåtgärder gällande FX-system, FTX-system, balkonginglasning och solpaneler på tak. Resultatet visar att med endast få ingrepp i referenshuset, i enlighet med regelverken, kunde energianvändningen reduceras från 147 kWh/m² till 104,8 kWh/m², vilket motsvarar 28,8 procent. / A majority of houses that were built during the years 1965-1974 is usually referred to as the million program. After 40-50 years of use, the buildings have reached their technical life expectancy and need to be renovated. At the same time, the lack of housing shortage continues to exist while energy requirements from the government are becoming increasingly strict. The government maintains and run a strict policy to reduce the energy consumption of the housing sector in hope of achieving a more sustainable society. The study is based on a multi-family house located in Kaverös, Gothenburg at Barytongatan 4, which is part of the Kaverös Stage II project. In this study, energy conservation measures are investigated in connection with story extension and the applicable regulations when it comes to rebuilding and upgrading in accordance with BBR and PBL. Using the IDA ICE simulation program, different energy conservation measures could be studied. The result of each individual energy conservation measure, and a combination of these were then compared with the existing building's energy declaration and static. This study is limited to energy calculation and no financial calculations are presented The result shows that only a few interventions in the reference housing, according to the regulations BBR and PBL, can affect the energy consumption and reduce it from 147 kWh/m² to 104.8 kWh/m², which corresponds to 28.8 percent.