Uppvärmningskostnader för äldre flerbostadshus utgör oftast en tung post i de löpandedriftskostnaderna. Att som fastighetsägare se över vilka alternativ till uppvärmning det finnspå marknaden kan leda till stora besparingar i en värld där energikostnader bara ökar ochökar. Lamellhus från perioden 1941-1960 utgör en stor andel av Sveriges bostadsbestånd ochär i behov av modernisering. I denna rapport studerar vi uppvärmningskällorna fjärrvärme ochgrundvattenvärmepump för en sådan byggnad ur ett kostnads- och miljöperspektiv.Genom att skapa en modell av byggnaden i VIP Energy beräknas behovet av tillförd energiför uppvärmning och tappvatten. Livscykelkostnader för de olika uppvärmningsalternativenberäknas under en 20-års period. Utsläpp som de olika systemen står för beräknas sedan förett år. Resultaten från LCC- och utsläppsberäkningen analyseras i diskussionen. De olikasystemen bedöms utifrån tre synvinklar: kostnader, miljöpåverkan och samhällperspektiv.En grundvattenvärmepump är klart att föredra ur det ekonomiska perspektivet. I miljö- ochsamhällsperspektivet är det dock svårare att definiera det bästa alternativet. Sett utifrån denenskilda byggnadens miljöpåverkan minskar grundvattenvärmepumpen utsläppen, dockskapar den ett ökat behov av primärenergi medan fjärrvärme utnyttjar befintliga lågvärdigarestprodukter som bränsle och producerar värme och el, vilket är positivt för både samhälleoch miljö. / Heating costs for older multi-dwelling buildings are usually a heavy item of operatingexpenditure. As a property owner, reviewing the options for heating available on the marketcan lead to big savings. In this report we study the heating sources district heating andgroundwater heat pump for a multi-dwelling building from a cost and environmentalperspective.A groundwater heat pump is clearly preferable from an economic perspective. However, it isdifficult to define the best option from an environmental and a society perspective. Thegroundwater heat pump reduces the individual building's emissions although it increases theneed for new produced energy on a society perspective.

District heating plays a major part of the energy system used for heat supply in Sweden. The starting point of this parameter study have been to investigate the possibilities to provide the area Tullkammarkajen with efficient district heating supply in help of low temperature residual heat and waste heat from a nearby industry. The area is located in the city center of Halmstad and is currently in its planning phase. Facilities and apartments are planned to be built.The study is based on three different parameters: type of system, system temperatures and energy demand. The different type of systems that is analyzed is conventional districtheating, low-temperature district heating with a heat pump as a complement as well as low-temperature district heating with the primary network’s feed line as a complement. Further comparison was made between these parameters, both from an energy wise perspective as well as from an economic perspective.The underlying idea to this study has been to obtain an energy efficient solution that at the same time suits the principle of sustainable development. However, it can clearly be seen in the presented results that it is more profitable to use more conventional methods that are not adapted to sustainable development, based on today’s market. Thus, the question becomes whether the future of innovative solutions or economical funds should be prioritized.

This project presents a feasibility study and an investigation of the potential for low temperature district heating system in Västerås. The investigation treats integrations possibilities for 4GDH (4th Generation District Heating) in Kungsängens area in Västerås, which is undergoing a large-scale building-up and construction.  The study is conducted for the company Mälarenergi AB. The advantages of 4GDH technology are identified and analyzed, where energy effectiveness and economic benefits aspects were concluded. Problems with existing technology and higher cooling demand expectations drive 4GDH to be an interesting and necessary technology in the future. Four Different integration solutions between old and new networks are presented, analyzed and discussed. Quantitative analysis conducted where initial cost for the four technical solutions were estimated and compared. The results show that low temperature district heating could lead to reduction in the initial cost for the network by using PEX instead of steel as pipe material. The results show also that one solution using heat exchanger as exchange stations has the lowest cost between the four solutions. The results show that the cost for the retention flow that is linked with 4GDH stands for 20%-30% of the total cost. The importance of the retention flow pipe is investigated using two physical models in OpenModelica and Excel, where simulations were conducted. It is concluded that it is possible to provide Kungsängen area with low temperature district heating without having the retention flow pipe. Three parameters were identified to be critical which are, geographical placement of the consumers, pattern variation for the heat demand and heat systems installed inside consumer’s buildings. The results show also that it might be critical to have a variate and optimized supply temperature for the area, depending on the demand. The simulations of a fictive area that could present a future heat demand for Kungsängen area shows that a temperature of 55°C is satisfying during winter season where the demand is high and a temperature between 60-65°C must be available during spring/autumn seasons and specially during summer. The variation depends directly on the temperature drop through the supply pipes to the consumers. The temperature drop is directly linked with water velocity inside the pipes. The losses increase during summer nights when the heat demand is low which lead to low water velocities.

With development within district heating leading to more incorporation of decentralized production, lowered temperature levels are required to enable these possibilities. Therefore, this study was conducted in collaboration with Fortum with the purpose of investigating and quantifying the effects of lowered delivery temperatures on mass flow and return temperatures. When these effects had been determined, the limiting factors were identified as well as the adjustments needed to enable the lowering delivery temperatures. This study is divided into two sections: a modeling of four type buildings and two case studies of specific areas of the Stockholm district-heating grid. The two sections of the study both use an Excel constructed model to examine the effects of the new proposed delivery temperature levels. The first section uses four type buildings with varying internal temperature levels to display how different secondary systems react to the changes in delivery temperature. The second section contains two case studies of outer parts of the grid where actual buildings are modeled. In the case studies the pipes speeds and secondary systems are analyzed to determine limiting factors for the lowering of the delivery temperatures. Overall this study contributes with quantified results of the effects of four lowered delivery temperature profiles on different customer systems. Analysis of the delivery temperatures showed that the largest change was shifting from the actual delivery temperatures of 2011 to the delivery profile that Fortum currently promised to deliver. The pipes of the studied areas were found not to be a limiting factor even in cases where the when mass flows increased three fold. The greatest limiting factor was determined to be the internal temperatures of the buildings, which set a strict limit and cannot be altered by Fortum without the customers’ cooperation. In conclusion a range of limiting factors were identified that proved to be potential limitations depending on the circumstances of a specific case. Depending on the investment needs in a specific case the economic viability was deemed to most likely be positive. When implementing lowered delivery temperatures in reality it is vital to acquiring data on secondary systems in order to identify the specific limitations of the proposed area. In addition an area of more research on the effects of lowered temperatures on the entirety of the grid as this study only investigates isolated sections.

This master thesis aims to develop an assessment tool for decision-making regarding future establishment of low-temperature district heating (LTDH). The tool is created as an indicator system on behalf of Södertörns Fjärrvärme AB (SFAB). SFAB is currently responsible for the distribution of high-temperature district heating (HTDH) to customers in the municipalities of Huddinge, Botkyrka, and Salem. The indicator system is designed to, in a first assessment step, examine the conditions that a delimited area has for conversion to lower system temperatures to be possible. Each indicator is quantified and graded. When using the system, a weighted final judgement is generated which indicates whether an area is suitable for LTDH or not. Furthermore, the purpose of this thesis is to also evaluate the tool by applying it to various areas within SFAB. This enables analysis and discussion regarding the tool's function in a real context. The development of the indicator system is the main result of the study. It consists of four indicators that take the following aspects into account: qualitative conditions (KA), conditions on the customer side (AA), the economic benefit (CRG), and the system condition (STA). The results from the implementation show that one out of five case-areas have good potential to be converted to LTDH, while the remaining cases fall below the limit for what is considered acceptable. No area from this project ends up over 75% of the maximum score, which would indicate very good potential. To validate the indicators, Pearson's correlation coefficient was calculated. The results show that there is a negligible to a weak correlation between all indicators, except KA & STA which has a strong correlation. For an HTDH area to be relevant for conversion to LTDH, the qualitative context of the area should be suitable, and the secondary side should be able to be supplied with lower temperatures. Furthermore, there should be an opportunity for increased system capacity and finally, a conversion should be economically beneficial. The application of the indicator system is an efficient and uncomplicated approach that makes it possible to identify areas that have the potential to develop district heating in a more sustainable direction. It is also possible for stakeholders to subsequently modify the indicator system if desired. In the longer term, the indicator system is an incentive for new business opportunities, increased energy efficiency, and increased economic benefits.

Hedemora Energi produces and distributes district heating in Hedemora and Säter. It is during the summer in these cities, as in the rest of the country, a low heating demand. By offering its customers district heating driven absorption cooling, this could be a way to satisfy more requests while being able to sell more heat and better use the available capacity.  In this thesis the cooling potential in Hedemora and Säter is calculated. Furthermore, the impact of integrated absorption chillers on district heating production, as well as absorption cooling profitability for Hedemora Energi is investigated. Simulations and calculations show that the system need to be adjusted for absorption cooling by increasing the supply temperatures during the hours that they are below the requirements of the absorption chillers. In addition, the adjustments cause raised return temperatures and altered flows in the network. This results in increased fuel costs and heat losses, reduced flow revenues and reduced heat supplies from flue gas condensers. Despite this, the economic results are positive for all cases. For example, over 44 thousand SEK in annual profit after integration of absorption chillers, producing 422 MWh of cooling in Skönvik, Säter.

Till följd av EU:s miljömål 2020 har svenska statliga och kommunala miljömål satts upp för att minska energianvändningen. EU:s 2020-mål syftar till att minska energianvändningen i Europa med 20 procent fram till år 2020 från det att målet sattes upp 2010. På kommunal nivå har detta inneburit att fastighetsbolag, privata men främst kommunala aktörer, har tvingats att se över sin energianvändning. Arbetet i denna rapport föranleds av en av de besparingsåtgärder som har vidtagits nämligen att komplettera befintliga fjärrvärmeuppvärmningssystem med värmepumpar. Uppdraget avser utveckling och utvärdering av en beräkningsmodell för denna typ av system. För att skapa ett pålitligt beslutsunderlag i arbetet med att minska energianvändningen krävs välgrundade beräkningar. Befintliga beräkningsmodeller lägger stor vikt vid ekonomiska faktorer och tar därmed liten hänsyn till tekniska aspekter och omgivande faktorer. Målet med arbetet har varit att skapa en beräkningsmodell vilken i större utsträckning speglar den faktiska situationen och påvisar ett mer välgrundat beslutsunderlag. Arbetet inleddes med en litteraturstudie vilken innefattade relevant forskning och grundläggande fakta om värmepumpar och fjärrvärmesystem. Beräkningsmodellen har utvecklats löpande under projektet där nya funktioner samt ny information ständigt tillkommit. Projektet har resulterat i en fungerande beräkningsmodell vilken innefattar fler parametrar än tidigare motsvarigheter. Tillsammans med uppdragsgivaren sattes tre olika mål upp för beräkningsmodellen, dessa var:  Att på ett intuitivt sätt presentera information och data.  Att skapa en transparent struktur vilken är enkel att följa.  Att skapa ett flöde genom modellen vilket följer en önskad arbetsgång. Dessa mål anses ha blivit uppfyllda, dock finns möjlighet till vidareutveckling. Modellen skulle exempelvis kunna kompletteras med mer automatiserade optimeringsberäkningar och justeras för att hantera andra typer av systemlösningar. / As a result of the EU's environmental 2020 goal, the Swedish government and municipal boards has put up internal goals to reduce energy consumption. EU 2020 goal aims to reduce energy consumption in Europe by 20 percent by the year 2020 from that the target was set in 2010. At the municipal level, this has meant that private but mainly public housing properties have been required to review their energy use. The work in this report is based on one of the savings measures that have been taken, which is to supplement existing district heating systems with exhaust air heat pumps. The project aims to develop a calculation model for evaluation and computation for this type of system. To create a reliable basis for decisions, efforts were made to produce just calculations. Existing computational models are focused on economic factors and thus takes little consideration of technological aspects and environmental factors. The aim of the work has been to create a computational model which more closely reflects the real situation and demonstrates a more informative decision basis. The work began with a literature review which included relevant research and basic facts about exhaust air heat pumps and district heating systems. The calculation model has been developed continuously during the project in which new functions and new information constantly has been added. The project has resulted in a working computational model which includes many more parameters than previous reviewed models. Together with the client three sub goals were set up for the model, these were:  To intuitively present information and data.  To create a transparent structure which is simple to follow.  To create a flow through the model, which follows a desired work process. These goals are considered to have been fulfilled in the developed calculation model, however, it's possible to further develop this model. The model could, for example, be supplemented with more automated optimization calculations and be adjusted to handle other kinds of heating systems.

The current energy context is characterized by the absolute necessity to reduce carbon emissions in order to tackle climate change and avoid its bleakest consequences. Furthermore, the overall energy supply system presents plentiful inefficiencies that lead to outrageous waste of energy.                 Spain's energy outlook is also marked by its astonishingly high energy dependence, which has contributed to its secular deficit in the trade balance.                 District heating systems permit to cover the heat demand from the residential, service and some components of the industrial sector utilizing excess heat that otherwise would be wasted, thus, reducing the total primary energy demand. In addition, they ease the development of renewables and enable a a reduction of greenhouse emissions and other hazardous gases.                 Despite its their advantages towards the fulfilment of climate change goals and the improvement of the country's economic situation,  they they only represent an insignificant contribution to Spain's heat demand. The main target of this dissertation has been to determine the economic feasibility of regarding the development of a district heating system in the Spanish city of Gijón.                 The city of Gijón counts on several parameters that allow the development of a centralized supply, such as several sources of excess heat and a high population density with little urban sprawl. However, other circumstances such as the low specific heat demands endanger the success of these systems.                 The first step towards the determination of the economic feasibility has been to assess the heat demands of the different subsectors that comprise the building stock. Particular care has been taken in order to attain the most realistic figures to supplement lack of official statistics with other sources. Furthermore, the final results have been compared to other independent evaluations, allowing to determine its accuracy.                 Following the calculation of heat demands, the attention is focussed on the estimation of the costs of the different elements that entail the construction and operation of a district heating system; the construction and maintenance of the distribution network, the heat supply, and the interface between the distribution network and the customer's systems, the substations. The assessment of these expenses has endeavoured to be rather conservative.                 The estimation of the specific cost of heat for the district heating system and its contrast with current forms of heat supply has allowed drawing the conclusion that the new network would be economically competitive despite the conservative assumptions taken. In addition, the system would practically eliminate the emissions of carbon dioxide and nitrogen oxides from the building stock.                 Finally, the viability of the system to changes in certain key parameters has been evaluated. Overall, the system's economic performance is not jeopardized by different configurations and solely two factors, the cost of capital and the connection rate could put at risk the success of the undertaking.

Vid förbränning av bränslen med hög vatten- eller vätehalt följer mycket av förbränningsenergin med denfuktiga luften som lämnar skorstenen vid anläggningen. Ett vanligt exempel är förbränning av trädbränsleeller hushållsavfall i kraftvärmeverk. För att öka anläggningens verkningsgrad och samtidigt rena luftenfrån svaveldioxid och metaller kan en rökgaskondensering av skrubbertyp användas. Svalt vatten sprutasin i en fyllkroppsbädd och möter där de heta rökgaserna. När rökgaserna kyls frigörs energi genom attvattnet i rökgaserna övergår från ångfas till vätskefas, energi som t.ex. kan användas för att värmafjärrvärmenätets returledning. Det här arbetet har utförts på uppdrag av Hifab DU-teknik som det senaste året har utfört studier ochberäkningar på rökgaskondenseringen vid Kraftvärmeverket Torsvik vilket har lett till förbättradeffektivitet. Genom simuleringar och beräkningar i bl.a. Matlab har författarna till den är rapportenförsökt verifiera de siffror för optimalt kondensatflöde som DU-teknik beräknat samt tittat på hur anläggningen påverkas av förändrade flöden och temperaturer i fjärrvärmereturen. En stor del av arbetet har legat i att förstå teorin kring värmeväxlare samt energi i fuktig luft på djupet.Det teoretiska ramverket vi satt upp kan ses som en grundlig introduktion till ämnena och en fördjupningav det vanliga kursinnehållet under Högskoleingenjörsutbildningen i maskinteknik vid Linköpingsuniversitet. Målet med det förberedande metodarbetet har varit att hitta uttryck för de olika temperaturerna ianläggningen som gör det möjligt att simulera förändringar i anläggningen. Modeller har tagits fram för attmed hjälp av de ingående temperaturerna i en värmeväxlare kunna simulera och beräkna de utgåendetemperaturerna givet olika massflöden. Modellen har visat sig fungera väl för värmeväxlaren som ärkopplad mot fjärrvärmenätet. Vid beräkningarna av temperaturer ut ur fyllkroppsbädden har två metodertestats. Författaren har studerat vad som händer om kondensattemperaturen ut ur fyllkroppsbädden sättstill daggtemperaturen för rökgaserna. Försök har också gjorts att betrakta fyllkroppsbädden som en sortsvärmeväxlare. Resultatet av författarnas beräkningar av kondensatflöde avviker till viss del från DU-tekniks beräknadekondensatflöden för ändrad pannlast i anläggningen. För att helt hamna på samma resultat behövde denvarma kondensattemperaturen anta en något högre temperatur än enbart daggtemperaturen. Antagandetär rimligt att göra men i vilken storleksordning är svårt att dra några slutsatser kring. Vad gäller metoden med att betrakta fyllkroppsbädden som en värmeväxlare finns där både framgångaroch brister. Framgångarna ligger i att trenden för de olika temperaturerna tycks stämma överens med denteori som författarna har lagt fram för värmeväxlare och vad som händer när de olika flödena går upp ochner i en värmeväxlare. Bristerna ligger dock i att metoden ej tar hänsyn till den värme som frigörs vidkondenseringen utan bygger helt på att medierna i bädden ej genomgår fasomvandlingar. Två viktiga förslag på fortsatt arbete lyfts fram i slutet av rapporten. Författarna ser dels att man iframtiden studerar möjligheten att betrakta fyllkroppsbädden som två separata värmeväxlare där de torrarökgaserna möter en delström av kondensatet och fukten i rökgaserna möter en annan delström avkondensatet. Vidare framförs en önskan om att man i framtiden testkör rökgaskondenseringen vid olikakondensatflöden under en längre tid för att uppnå stationära förhållanden i temperaturerna vilka senarekan användas för att ta fram matematiska uttryck för vad som händer med de utgående temperaturerna utur fyllkroppsbädden när kondensatflödet förändras eller när den ingående temperaturen tillfyllkroppsbädden ökar eller minskar. / When burning fuels with high water or hydrogen content, much of the combustion energy follows themoist air that leaves the chimney at the plant. A common example is the combustion of wood fuel orhousehold waste in CHP-plants. In order to increase the plant's efficiency and at the same time clean theair from sulfur dioxide and metals, a flue gas condensation of scrubber-type can be used. Cool water isinjected into a filling bed and meets the hot flue gas. When the flue gases are cooled, energy is released bythe water in the flue gases when vapor turns into liquid form, energy that can be used e.g. to heat thedistrict heating network's return line. This work has been carried out on behalf of Hifab DU-teknik, which in the past year has carried outstudies and calculations of the flue gas condensation at the Torsvik CHP plant, which has led to improvedefficiency. Through simulations and calculations in Matlab, this report tries to verify the optimalcondensate flow calculated by DU technology and study how the plant is affected by changed flows andtemperatures in the district heating network’s return line. The authors of this work have put a lot of effort into understanding the theory of heat exchangers andenergy in moist air in depth. The theoretical framework we set up can be seen as a thorough introductionto the subjects and an in-depth study compared to the usual course content during the Bachelor's degreeprogram in mechanical engineering at Linköping University. The goal of the preparatory method work has been to find expressions of the different temperatures inthe plant that make it possible to simulate changes in the plant. Models have been developed to be able tosimulate and calculate the outgoing temperatures given different mass flows using the ingoingtemperatures in a heat exchanger. The model has proven to work well for the heat exchanger, which isconnected to the district heating network. In the calculations of temperatures out of the filling bed, twomethods have been tested. The authors’ has studied what happens if the condensate temperature out ofthe filling bed is set to the dew temperature of the flue gases. Attempts have also been made to considerthe filling bed as a kind of heat exchanger. The result of the authors' calculations of condensate flow differs to a certain extent from the DU-teknik’scalculated condensate flows during a changed boiler load in the plant. To end up at the same result, thehot condensate temperature needed to take a slightly higher temperature than the dew temperature. Theassumption is reasonable to make, but it is difficult to draw any conclusions about the magnitude. Regarding the method of considering the filling bed as a heat exchanger, there are both successes andshortcomings. The success lies in that the trend for the different temperatures seems to be in line with thetheory that the authors have presented for heat exchangers and what happens when the massflowsincrease or decrease in a heat exchanger. However, the shortcomings lie in the fact that the method doesnot take into account that heat is released during the condensation, but is based entirely on the fact thatthe fluid in the filling bed do not undergo phase transformations. Two important proposals for continued work are highlighted at the end of the report. It would beinteresting to study the possibility of considering the filling bed as two separate heat exchangers, where thedry flue gases encounter a partial current of the condensate and the moisture in the flue gases meetsanother partial current of the condensate. Furthermore, a desire is made to test the flue gas condensationin the future at different condensate flows for a longer period of time in order to achieve stationaryconditions in the temperatures. The data can later be used to produce mathematical expressions of whathappens to the outgoing temperatures of the filling bed when the condensate flow changes or when theingoing temperature of the filling bed increases or decreases.

Världens energianvändning är en central del i rådande klimatförändringar och smarta tekniklösningar tillsammans med nya beteendemönster är våra bästa verktyg för att minimera vår påverkan på planeten, däribland mest omtalat användningen av fossila bränslen. Detta arbete har utförts i samarbete med Caverion på beställning av Alimak group AB i Skellefteå, med syfte att undersöka gångbarheten i ett byte av värmekälla på en av Alimaks fastigheter, ifrån oljeeldning till fjärrvärme. Målet för arbetet har varit att ta fram ett konkret åtgärdsförslag, med tillhörande ekonomisk analys av lönsamheten i framlagt förslag. Genom undersökningar i form av litteraturstudier, beräkningar och platsbesök fastslogs fastighetens huvudsakliga effektbehov och ett helt nytt värmesystem dimensionerades. Energianvändningen beräknades varpå de teoretiska driftkostnaderna kunde tas fram och jämföras mellan dagslägets värmesystem samt med det förslagna åtgärdspaketet och dess kostnader. Resultatet blev ett komplett åtgärdsförslag där en investering på ungefär 555 Tkr innebär att fjärrvärme installeras på fastigheten och ett helt nytt värmedistributionssystem etableras. Tanken är att använda moderna fläktluftvärmare för att cirkulera rumsluften och värma upp den så att effektbehovet tillgodogörs med godtycklig marginal mot de osäkerheter som finns beräkningarna inbördes. Det föreslagna värmesystemet utmynnar i väsentligt minskade driftkostnader som betyder en årlig besparing på 380 Tkr med det nya värmesystemet och 480 Tkr om även ventilationen byggs om enligt Caverions förslag samtidigt. Vidare erhålls även en minskad klimatpåverkan av cirka 244 ton koldioxid per år. Utöver dessa huvudsakliga fördelar med förslaget så erhålls också en helt ny nivå av driftsäkerhet, reglerbarhet och översikt av anläggningen som i dagsläget inte finns. Med modern teknik kan hela värmesystemet styras centralt och automatiskt, samt kopplas ihop med förslaget ventilationssystem för en helt automatiserad drift av anläggningen. / The current energy usage worldwide is playing a central part in polluting the atmosphere and accelerating climate change. Intelligent technical solutions coupled with new behavioral patterns are our best tools to battle climate change and minimize our impact on the planet. Amongst these innovations and changes to our lifestyle, a central part is our usage of fossil fuels, of which usage is being restricted by governments worldwide, commonly via taxes. This forces us to reinvent ourselves and search for other options where we can, to minimize both our costs and our emissions of greenhouse gases.   Alimak in Skellefteå is currently finding themselves in a similar situation, and therefore requested a proposal for a new heating system on one of their properties to be delivered by Caverion via this report. The task at hand was to investigate the viability of changing out their current heating sources, three oil-furnaces to a new district heating powered system, and come up with a concrete proposal for a solution, and evaluate the economical profitability. Through a broad study of literature on the subject and several trips to the property to examine it, the heating power required to maintain an arbitrary indoor climate was calculated, with respect to the buildings shell, ventilation and infiltration. With this accomplished an entirely new heating system could be dimensioned to fit the property based on the given conditions. With this all done, the buildings annual energy consumption could be calculated and from that the theoretical operational costs emerged, to be compared with the oil-furnaces of today. The results of it all, is a proposal for a complete new heating package including fan-heaters, piping, control system and district heating substation. Amounting to an investment of 555 000 SEK, the system is deemed adequate to maintain a comfortable climate and circulate the warm air throughout the entirety of the rooms wherein the heaters are placed, and provide a sufficient margin of power given the uncertainties within the calculations. The investment turns out to lower the operational costs significantly, and an estimated 380-480 000 SEK will be saved annually depending on which of the options are chosen. Furthermore since this means that none of the oil-furnaces will remain, all the carbon dioxide emissions associated with heating the building are eliminated, previously amounting to a rough 244 tons annually in previous years. Needless to say this is a phenomenal gain for the environment. In addition to these main advantages of the proposal, there is also the completely enhanced level of operational reliability, controllability and overview of the plant that has previously not been available. With modern technology, the entire heating system can be controlled centrally and automatically and together with the proposed ventilation system the entire operation of building can be run fully automatically.