Energy efficiency is important both to reduce costs and to reduce greenhouse gas emissions in the atmosphere. Reducing costs will also help maintain business competitiveness. Scania in Södertälje is a company where the optimization of energy use is an ongoing and continual process. One area with potential to make energy and cost savings is the effectiveness of the ventilation systems in offices and industrial premises at Scania. During the summer months an increased demand for cooling occurs, leading to increased ventilation and a peak in district cooling system usage. Sorptive cooling is a technology where the supplied air is cooled by applying external heat. This technique involves a reduction in electricity consumption compared to electrically-powered cooling machines and does not affect the district cooling system usage. It was therefore of interest to investigate if sorptive cooling would be an energy efficient and viable solution for Scania in the future. This investigation shows that sorptive cooling requires more power than a conventional ventilation system. Despite the fact that Scania has access to free heat during the summer months, the study shows that sorptive cooling would not be economically viable to install in the industrial premises, where no cooling systems currently exist. However, compared to an electrically-powered cooling machine, sorptive cooling is anyway more energy efficient. The conclusion is that sorptive cooling is a viable solution for the offices, but not for the industrial premises at Scania in Södertälje

The real estate company Ihus is facing an expansion of its comfort cooling in Noatun,Uppsala, to provide the buildings in the block with cooling. The buildings in Noatunare mainly used for office premises, where the requirements for an accepted indoorclimate is great. However, it’s uncertain whether Ihus should continue, as currently,producing comfort cooling by themselves using a compressor chiller, or if they shouldconnect themselves to Vattenfall’s district cooling net. The purpose of this report is to examine which technique of cooling is best suited forIhus and their buildings in Noatun. It should also work as a guideline for othercompanies facing the same problem as Ihus. In addition, the result should give an ideaof how cooling by using compressor chillers compares to district cooling in aneconomical perspective, aswell as in an environmental and performance perspective. This report is based mainly on studies of literature covering cooling, approximationsof contractor costs with the help of the calculation tool Wikells Sektionsdata andassays of life cycle costs for different refrigeration alternatives. The result is showing that refrigeration by using compressor chillers seems to be themost advantageous option for the buildings in Noatun. Investments of a newcompressor chiller and associated components to cover the cooling demand in theblock appears to be a better option than district cooling.The costs of district cooling varies greatly depending on its origin and geographicallocation. Because of these great variations, it’s difficult to come to a conclusion onwhat type of comfort cooling is the least expensive in all situations. Every uniquesituation requires an investigation.In order to determine the impact on the environment for each type of comfortcooling a more thoroughly analysis is required. However, district cooling is likely tobe a better option regarding the environmental impact due to a centralizedpreparation of the refrigerants. A centralized preparation allows easier environmentalefficiency work since it’s easier to oversee emissions in one large facility than in manysmaller ones. The performance of different types of comfort cooling has shown to be too difficultto compare in this report. The reason for this is mainly because of limited access ofinformation regarding performance, but also because district cooling and cooling byusing compressor chillers differs greatly technically. Therefore, it’s difficult to conducta fair comparison of their performance.

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.

<p>The use of air-conditioning and comfort cooling in offices and stores has been increasing during recent years. Adnot, (2002) reports an increased use in commercial buildings by 200 % from 1990 to 2002. The increase is primarily due to the growing use of electrical equipment generating internal heat. The enhanced public demands of the indoor climate are yet another explanation to the increase. The main cooling method used is mechanical chillers based on vapor compression. Many of these cooling systems are old and will shortly become obsolete which gives the property holder a chance to improve in his cooling system.</p><p>The office building Mercurius 12 in Karlstad operates activities that require comfort cooling. The cooling method used is conventional vapor compression which is distributed by an airborne system. The property consists of two buildings one built in 1939 and one in 1970. The property is 7700 m² and accommodates one apartment, offices and stores. The property is currently housing 190 people.</p><p>The aim of this report is that on a basis of life-cycle costs analyze how a change of cooling methods and cooling needs are connected to the Life-cycle costs of the cooling. The practicability of each change shall also be investigated.</p><p>The calculation of the life-cycle costs and heat surpluses have been made using generally accepted formulas that has been outlined in Excel.</p><p>All of the simulated measures to reduce the building's life-cycle costs in terms of internal heat and solar radiation pays off. The higher energy prices, the greater savings.</p><p>The Cooling tower method is the chilling process that provides the minimum life-cycle costs, both with both air and waterborne distribution system.</p><p>Vapor compression used with today’s energy prices provides comparatively to the other investigated methods a low life-cycle cost. The vapor compression method is however not as good if the energy price would get higher than today.</p>

The use of air-conditioning and comfort cooling in offices and stores has been increasing during recent years. Adnot, (2002) reports an increased use in commercial buildings by 200 % from 1990 to 2002. The increase is primarily due to the growing use of electrical equipment generating internal heat. The enhanced public demands of the indoor climate are yet another explanation to the increase. The main cooling method used is mechanical chillers based on vapor compression. Many of these cooling systems are old and will shortly become obsolete which gives the property holder a chance to improve in his cooling system. The office building Mercurius 12 in Karlstad operates activities that require comfort cooling. The cooling method used is conventional vapor compression which is distributed by an airborne system. The property consists of two buildings one built in 1939 and one in 1970. The property is 7700 m2 and accommodates one apartment, offices and stores. The property is currently housing 190 people. The aim of this report is that on a basis of life-cycle costs analyze how a change of cooling methods and cooling needs are connected to the Life-cycle costs of the cooling. The practicability of each change shall also be investigated. The calculation of the life-cycle costs and heat surpluses have been made using generally accepted formulas that has been outlined in Excel. All of the simulated measures to reduce the building's life-cycle costs in terms of internal heat and solar radiation pays off. The higher energy prices, the greater savings. The Cooling tower method is the chilling process that provides the minimum life-cycle costs, both with both air and waterborne distribution system. Vapor compression used with today’s energy prices provides comparatively to the other investigated methods a low life-cycle cost. The vapor compression method is however not as good if the energy price would get higher than today.

Det här arbetets syfte är att ge förslag på ny kyllösning i en kommersiell fastighet. Den nuvarande lösningen innebär att kylan kommer ifrån tappkallvatten som spolas in i en värmeväxlare, den här lösningen är både dyr och har en negativ påverkan på vår miljö, fastighetsägaren är inte nöjd med detta och vill göra om systemet. Då det inte finns några direkta mätvärden från systemet förutom vattenförbrukningen så är effekt-och energibehovet en osäkerhet. Två driftfall har tagits fram där driftfall 1 och driftfall 2 har ett effektbehov på 80 kW respektive 130 kW. Utifrån driftfallen har effekt- och energiprofil tagits fram. Med hjälp av profilerna har en ny lösning tagits fram men med fyra olika metoder. Undersökningen tar upp lösningar med fjärrkyla, bergkyla, absorptionskyla och kompressorkyla. Fjärrkylan är idag inte ett möjligt alternativ då det fortfarande inte finns ett fjärrkylanät men diskussionerna pågår om ett sådant nät och på grund av detta är fjärrkyla med som en möjlig framtida lösning. Undersökningen visar att fjärrkyla inte är ett lönsamt alternativ, detta eftersom man behöver behålla nuvarande lösning fram till dess. Absorptionskyla är inte heller ett bra alternativ och det beror på det höga fjärrvärmepriset. Det visar sig att lösningen med bergkyla eller kompressorkyla är de bästa alternativen där en kompressordriven kylmaskin ses som den mest lönsammaste men ur en miljöaspekt är den det mindre bra även om den kylmaskin som används i denna undersökning använder sig av ett köldmedium med förhållandevis lågt GWP-värde. / This study’s purpose is to give suggestions of a new cooling system in a commercial building. The current system implies that the cooling come from tap cold water that flushes into a heat exchanger, this solution is both expensive and have a bad impact on the environment. The property owner isn’t satisfied with this and want to remake the system. There isn`t many measurement values that I can use to calculate the effect and energy needs for the building except the water consumption in the cooling system. Because of this uncertainty two cases have been used in this study. The first has an effect need of 80 kW and the other have an effect around 130 kW. From these two cases has an effect and energy profile been made from each of the two cases. With the profiles made, can a new solution be presented and in this study we have four different methods for the cooling system. An investigation has been made on district cooling, ground cooling, absorption cooling and compressor cooling. The district cooling isn`t possible today because it doesn’t exist but the local energy company having discussions about it and because of this, district cooling is a possible future solution. The study shows that to wait for a district cooling isn´t a profitable solution, neither is the solution with the absorption cooler, the absorption machine is being driven by district heat and the price is too high in Bollnäs. This study shows that ground cooling or compressor cooling are the best options in this case. The compressor cooling is the most profitable, but it has a downside in the environment perspective. All energy is based on electricity energy, and the refrigerant can affect the environment in a bad way if it´s a leak. But I should say that the cooling machine used in this study uses a refrigerant that has a relatively low GWP-value.

The idea of snow cooling in this case is to save snow from winter to summer and to use it for air conditioning and for saving energy in the production of ice in hockey arenas. Today in Sweden, snow power on a large scale is used only on one place, the hospital in Sundsvall. There you’ll find a pond with 70 000 m3 of snow. The melt water in the pond is heated up while cooling down warm air from the hospital, before circulating back to the pond where it regains a low temperature passing through the snow. The idea was to examine the possibility to use such a system in Västerås, at the multiple sports arenas at Rocklunda, partly for air conditioning and partly for ice production. This work was made possible through gathering information on snow storage and on the Sundsvall snow cooling plant, by interviewing people with insight in the Sundsvall hospital and Rocklunda sports arenas and by calculating the electricity consumption, necessary amount of snow and making an LCC-analysis. For air conditioning the melt water would be used like in Sundsvall but for ice production the melt water would be used for condensing the cooling media in the heat pump at a lower temperature then it would do while cooling with air or river water during summer. Annual electricity savings of 120 and 154 MWh for the arenas were made for 2016 and 2017 when using the snow for ice production. For the air conditioning the saving were estimated to around 55 MWh per year. A snow dispatch hatch in one of the hockey arenas made an alternative to a full-scale snow cooling system. Using this hatch for temporal snow power could save up to 62 MWh per year when used for ice production and 38 MWh when used for air conditioning. The estimated costs for construction of said system proved to be too expensive for making a full-scale snow power system a reality. For ice production a storage of 103 000 m3 of snow was needed which made for a result of -57 MSEK in the LCC-analysis. For the air conditioning alone, a storage of 6 000 m3 was needed which made for a result of -4.2 MSEK. The snow dispose hatch, even without the need of snow storage, resulted in -5.9 MSEK for ice production and -1.6 MSEK for air conditioning. With more thoroughly estimations of the investment costs, together with global warming and thus bigger potential for saving energy, this might be a promising investment in the future.

Idag finns det ett flertal krav och rekommendationer från myndigheter vilka syftar till att reglera och hålla nere energianvändningen i kontorsbyggnader. I Boverkets byggregler, BBR, finns vägledning till hur kraven kan uppfyllas. Med detta som utgångspunkt genomförs det idag energiberäkningar i projekteringsskedet för att säkerställa att den blivande verkliga energianvändningen ej överstiger den tillåtna. Tidigare studier har visat att det trots detta ändå har varit vanligt förekommande att den verkliga energianvändningen har överstigit den beräknade och i en del fall även den tillåtna.Syftet med denna studie var att undersöka om det föreligger skillnader mellan de beräknade och de uppmätta värdena för kontorshus, samt vilka de bakomliggande orsakerna är. Även en analys kring de olika faktorerna som påverkar energianvändningen har genomförts. Det innebär att för att uppfylla syftet med studien har tre frågor ställts och dessa har besvarats genom undersökningar. Frågorna är: Vad har tidigare studier inom ämnet visat? Vilka orsaker kan det finnas om det uppstår skillnader mellan det beräknade och uppmätta energivärdet? Vad kan göras annorlunda för att få ett bättre resultat?För att kunna besvara frågeställningarna har det samlats in ett års mätningar av energianvändning (uppvärmning, komfortkyla och fastighetsel) för två olika kontorsbyggnader för att kunna visa om det går att bygga energieffektiva lokaler. För respektive kontorsbyggnadhar nödvändig information samlats in från respektive byggherre som har redovisat energiberäkningar med uppskattat energibehov. Den uppmätta uppvärmningen (fjärrvärmeanvändning och uppvärmning av tappkallvatten) har normalårskorrigerats enligt energiindexmetoden för att kunna jämföras med beräknade värden. Litteraturstudie och hypoteser om orsaker till avvikelser mellan beräknat och uppmätt finns användes och analyserades noggrannare för respektive kontorsbyggnad.Den specifika energianvändningen för respektive kontorsbyggnad uppnår Miljöbyggnads kravnivå Brons respektive Silver. För kravnivån Brons gäller att den specifika energianvändningen för en tillbyggnad ska vara under 80 !"ℎ $% och för kravnivån Silver för en ombyggnad under 118 !"ℎ $%. Däremot varierar användningen av energi för uppvärmning och komfortkyla där de månadsvis uppmätta värdena för respektive kontor överstiger det beräknade under året 2017. Det finns flera orsaker till att beräknat energibehov är för lågt på grund av energiberäkningsprogrammet som använts, IDA Indoor Climate and Energy (IDA ICE). En del indata kan ha över- eller underskattats. Exempelvis kan utnyttjandet av tillskottsenergi ha överskattats. För låg innetemperatur och att ingen hänsyn till effekten av köldbryggor tas med kan bidra till att beräknat värmebehov blir för lågt.För att uppnå bättre resultat på de månadsvis uppmätta värdena för kontorsbyggnaderna krävs noggrannare energiberäkningar med realistiska indata, vilket kan innebära att alltför höga värden på energianvändning kan upptäckas och åtgärdas under projekteringsstadiet. Det krävs kunskaper om hur byggnader kan bli energieffektiva vid användning och inte endast när byggnaderna projekteras. / Today, there is a number of requirements and recommendations by government agencies which aim to regulate and reduce energy consumption in office buildings. Boverket Byggregler, BBR, provides guidance on how to meet such requirements. With this as a starting point, calculation to determine energy usage are currently carried out in the design phase to ensure the future energy consumption does not exceed the allowed rate. However, previous studies have shown it is quite common that the actual energy consumption rate exceeds the calculated or even the allowed rate.The purpose of this study is to investigate whether there are differences between the estimated and the measured values for office buildings. Additionally, this review intends to determine the underlying causes of those differences. An analysis of the various factors that affect energy use has also been conducted and the necessary information to complete such analysis has been collected through interviews with the developer.The survey, the actual energy use for the two examined offices exceeds the calculated energy consumption value. Furthermore, the survey shows near large windows, the energy usage was higher due to having more window area, resulting in heat during the summer and needs more energy for cooling down the office buildings.The specific energy use for each office building achieves Miljöbyggnad:s requirement level Bronze and Silver. For the requirement level Bronze, the specific energy use for an extension must be below 80 kWh/m^2 and for the requirement level Silver for a reconstruction shall be 118 kWh/m^2. On the other hand, the use of energy for heating and comfort cooling varies where the monthly measured values for each office exceed that calculated during the year 2017. There are several reasons why estimated energy requirements are too low due to the energy calculation program used, IDA Indoor Climate and Energy (IDA ICE). ), some input data may have been overestimated or underestimated. For example, the use of additional energy can be overestimated, too low indoor temperature and that no consideration of the effect of cold bridges can be included can contribute to the calculated heat requirement being too low. Therefore, it is too early to draw any conclusions as more and more surveys are needed before being able to generalize the results.

This master thesis examines how buildings should be designed in the future, in terms of facades and cooling systems, in order to achieve desired indoor temperatures. The basis of the thesis is the expected increase in outside temperature, due to climate change, and the fact that several hundred people died in 2018, as a result of the heat wave that was in Sweden that year. To examine future indoor temperatures, a model of an apartment building in southern Stockholm was created in the software IDA Indoor Climate and Energy, IDA ICE, as well as future climate files for the same geographic position. The climate files were based on future climate scenarios and local data, in order to be as realistic as possible. The model of the building was simulated during the summer months, beginning of June to end of August, with the focus of receiving the indoor temperatures for year 2030 and 2060. For the year 2060 a sensitivity analysis was made in order to see how a change in building design, to analyze how it may affect the indoor temperatures.The results indicates that the indoor temperatures will continue to increase, as a result of the climate change, and that building design played a small role in lowering the indoor temperatures when it comes to changes in facades, but a bigger role for cooling systems. Peaks of 33°C for the year 2060 was lowered to 25°C when cooling systems where implemented, while changes in facades only lowered the peaks to 32°C.The conclusion for this master thesis is therefore that when it comes to buildings in the future, cooling systems should be considered, as well as changes in the facades, in order to achieve desired indoor temperature. Solar film on the windows and awnings can be used to reduce the indoor temperature, but the balance between daylight admission and heat transmission is important to consider. Rotation of the building and the presence of shading objects, such as balconies and surrounding buildings, also affect the indoor temperature in apartment buildings and should therefore be considered in new construction.

During renovation Ljusåret 2 was converted to a modern office with an activity based work style (ABW) with a Demand Controlled Volume (DCV) ventilation system connected to a closed-loop duct. Cooling is provided through air handling units and active water based beams, the underfloor heating system was kept. Written instruction and specification have been studied for the two different control systems Schneider EcoStructure and Lindinspect. Both control systems have been analyzed according to time schedule, set-point and process value by using different functions in software. To be able to perform a energy audit and look at indoor climate for Ljusåret 2 there have been studies according to underfloor heating, constructions of ventilation system, diversity factor for DCV, closed-loop-ducts, heat losses from ducts, cooling demand and energy certification. According to this audit, energy performance is calculated to 89.1 kWh/m2 according to building energy, activity energy is not audited or calculated. During design phase, an energy calculation was made by an energy consultant with the result of 81.3 kWh/m2. The estimated performance is a 9.6 % increase. This building is designed for Miljöbyggnad certification of level silver and should be ≤ 109 kWh/m2,year. According to audit and calculation for energy performance this level is possible to keep. The estimated energy performance have been calculated with only 4 month of statistics from January until April 2019 because Ljusåret 2 have just been renovated. District heating has been estimated through the energy signature by data from energy meter. Electrical components for the building have been measured and energy usage calculated. Energy produced by compression chiller have been estimated with calculated performance from design phase and adding heat transfer between rooms and supply ducts. Energy between rooms and supply ducts were not included in energy calculation during the design phase. According to the control system for the DCV system there have been some issues with high temperature in supply ducts even when they are supplied with 15 ºC from air- handling unit. There have been measurement to the ventilation system 5701-5704 that is connected to a close-loop duct with a result of temperatures between 15.2 ºC up to 21.4 ºC and the velocity has varied between 0.05-2.1 m/s in different measurement spots. This is an increase of 6.4 ºC. A heat transfer calculation have been made in Paroc Calculus to estimate heat transfer between room and supply ducts. The results of this calculation indicates the same level of temperature increases as when the system was measured. With no thermal insulation cooling capacity is lost to half after less than 5 m with a velocity of 0.2 m/s, after 15 m with a velocity of 1 m/s and 30 m with a velocity of 2 m/s . This should be compared with supply duct with 20 mm of thermal insulation that has lost its cooling capacity after less than 13 m with a velocity of 0.2 m/s, after 63 m with a velocity of 1 m/s and is increase with 4 ºC after 100 m with a velocity of 2 m/s. Using closed-loop ducts with velocity below 2.0 m/s and without thermal insulation combined with under tempered supply air is not a good combination. Even short length with low velocity and lack of thermal insulation is devastating because of heat transfer according to logarithmical temperature difference between room and supply ducts. A closed-loop duct is often designed as a pressure chamber and recommended when using DCV and/or VAV ventilation to avoid problems with noise and to be able to reduce the need of dampers. Problems with temperature increasing according to velocity in ducts must be taken in consideration. For Ljusåret 2 this will affect district heating usage where ducts are placed because underfloor heating must compensate heat transfer. Chilled water must be provided an extra time for rooms with both DCV and chilled beams and rooms with only DCV is less comfortable which they could been with a correct installation.