According to a decision of the European Commission, measures are to be taken to reduce the use of energy in the EU. The goal is to reduce it by 20 % compared to the current use. This shall be done to the year 2020 (European Commission, 2011). One industry that use large amounts of energy is the construction of buildings which account for almost a third of the energy use (Brogren, 2012). The major part of the energy that is used in the construction industry is not used when the buildings are built, but rather during the rest of their subsequent lifetime. There is a great potential to save energy by reducing the energy that is used to maintain a satisfactory indoor climate. Recovery of excess heat and excess cold is a solution that the European Commission think has the biggest potential to reduce the total energy consumption. The most common system used for energy recovery is air to air heat exchangers connected with the supply air and the exhaust air. For different reasons it is not possible to use this kind of system in several buildings. If that is the case there is a possibility to use a liquid coupled recovery system instead. If an additional source of excess heat or excess cooling exist within the building, or nearby, it is also possible to connect this to the system which would increase the ability to save energy even more. The purpose of this thesis has been to develop a tool for energy calculations in liquid-coupled recovery systems. This tool has been developed in the program IDA ICE (used for energy calculations) and has made it possible to perform dynamic simulations in this kind of system over the timeframe of a whole year and with a very short calculation time. The tool is flexible in terms of its components and system design so it can be used for several different types of projects. Everything from simple systems with fixed brine flow with only one supply air and exhaust air unit to systems with several units, various types of control possibilities and an addition of excess heat from, for example, a room containing computer servers. The tool that has been developed has been verified and used to calculate the potential to save energy in a system that is installed at the Ångström laboratory in Uppsala. The tool has shown that with the kind of control and the conditions that currently exist at the laboratory the energy consumption could be reduced by 444 MWh which in this case almost is 50 % of the current energy consumption. Besides the recovery system in Ångström two more systems have been investigated, a server room for The Royal Institute of Technology and the server halls that Facebook is building near Luleå town. The investigation shows that there exist very large amounts of heat that is possible to recover in buildings that include server rooms and that the installed recovery systems, if there are any, in many cases could be improved. Besides constructing recovery systems that recover heat or cold in buildings it is also possible to build this kind of system that recover heat or cold between buildings in the same area. The tool can also be used to investigate how such a system should work in order to minimize the use of energy as much as possible. A solution where heat and cold is recovered between multiple buildings is a solution that probably will be very interesting in the future, which means that this tool could come in handy.

Enligt ett beslut från EU-kommissionen ska åtgärder genomföras för att energianvändningen inom EU ska minska. Minskningarna ska motsvara ungefär 20 % av dagens energianvändning och ska uppnås till år 2020 (Europeiska Kommissionen, 2011). En sektor som använder stora mängder energi är byggbranschen som står för nästan en tredjedel av energianvändningen i samhället (Brogren, 2012). Den största delen av energin används inte under uppförandetiden utan under byggnadernas efterföljande livstid. Det finns därför stora besparingar att göra om energin som krävs för att upprätthålla ett tillfredsställande inomhusklimat minimeras. Återvinning av överskottsvärme och överskottskyla är den åtgärd som enligt EU-kommissionen har den största potentialen för att minska den totala energianvändningen. Det vanligaste systemet för energiåtervinning är luftvärmeväxlare mellan tilluften och frånluften men i flera byggnader är denna typ av system av olika anledningar inte möjliga. I dessa fall kan vätskekopplade återvinningssystem användas. Om en extra källa för överskottsvärme eller överskottskyla finns inom byggnaden, eller i närheten, kan också en sådan anslutas vilket i sådana fall ger ännu bättre förutsättningar att spara energi. Syftet med examensarbetet har varit att tillverka ett verktyg för energiberäkningar i vätskekopplade återvinningskretsar. Detta verktyg har utvecklats i energiberäkningsprogrammet IDA ICE och har gett möjligheter att utföra dynamiska helårssimuleringar av vätskekopplade återvinningssystem på väldigt kort tid. Verktyget är dessutom flexibelt vad gäller dess komponenter och återvinningssystemets utformning varför det kan användas till flera olika typer av projekt. Allt ifrån enkla system med fast köldbärarflöde och återvinning mellan endast ett tillufts- och frånluftsaggregat till system med flera aggregat, olika typer av styrning och tillskottsvärme från exempelvis en serverhall. Det utvecklade verktyget har också verifierats och använts för att beräkna möjlig energibesparing på ett system som återfinns på Ångströmslaboratoriet i Uppsala. Med den styrning och de förutsättningar som råder i skrivande stund visade verktyget på möjligheter att minska energianvändningen med 444 MWh, vilket motsvarar en minskning på nästan 50 % för det aktuella systemet. Förutom Ångströmslaboratoriet har även förutsättningar för Kungliga Tekniska Högskolans serverhall och Facebooks serverhallar i Luleå undersökts. Utredningen visar att det finns mycket stora mängder värme att återvinna i byggnader som innefattar serverhaller och att återvinningen, om det finns någon, ofta inte är optimal. Förutom att återvinna värme och kyla inom byggnader är det också möjligt att bygga denna typ av system mellan byggnader inom samma område. Verktyget kan även användas för att utreda hur ett sådant system skulle fungera för att ge så stora energibesparingar som möjligt. En lösning där värme och kyla återvinns lokalt mellan flera byggnader är något som troligen kommer att vara mycket intressant i framtiden varför detta verktyg kommer att komma väl till pass. / 1           According to a decision of the European Commission, measures are to be taken to reduce the use of energy in the EU. The goal is to reduce it by 20 % compared to the current use. This shall be done to the year 2020 (European Commission, 2011). One industry that use large amounts of energy is the construction of buildings which account for almost a third of the energy use (Brogren, 2012). The major part of the energy that is used in the construction industry is not used when the buildings are built, but rather during the rest of their subsequent lifetime. There is a great potential to save energy by reducing the energy that is used to maintain a satisfactory indoor climate. Recovery of excess heat and excess cold is a solution that the European Commission think has the biggest potential to reduce the total energy consumption. The most common system used for energy recovery is air to air heat exchangers connected with the supply air and the exhaust air. For different reasons it is not possible to use this kind of system in several buildings. If that is the case there is a possibility to use a liquid coupled recovery system instead. If an additional source of excess heat or excess cooling exist within the building, or nearby, it is also possible to connect this to the system which would increase the ability to save energy even more. The purpose of this thesis has been to develop a tool for energy calculations in liquid-coupled recovery systems. This tool has been developed in the program IDA ICE (used for energy calculations) and has made it possible to perform dynamic simulations in this kind of system over the timeframe of a whole year and with a very short calculation time. The tool is flexible in terms of its components and system design so it can be used for several different types of projects. Everything from simple systems with fixed brine flow with only one supply air and exhaust air unit to systems with several units, various types of control possibilities and an addition of excess heat from, for example, a room containing computer servers. The tool that has been developed has been verified and used to calculate the potential to save energy in a system that is installed at the Ångström laboratory in Uppsala. The tool has shown that with the kind of control and the conditions that currently exist at the laboratory the energy consumption could be reduced by 444 MWh which in this case almost is 50 % of the current energy consumption. Besides the recovery system in Ångström two more systems have been investigated, a server room for The Royal Institute of Technology and the server halls that Facebook is building near Luleå town. The investigation shows that there exist very large amounts of heat that is possible to recover in buildings that include server rooms and that the installed recovery systems, if there are any, in many cases could be improved. Besides constructing recovery systems that recover heat or cold in buildings it is also possible to build this kind of system that recover heat or cold between buildings in the same area. The tool can also be used to investigate how such a system should work in order to minimize the use of energy as much as possible. A solution where heat and cold is recovered between multiple buildings is a solution that probably will be very interesting in the future, which means that this