Lower energy use in buildings is a result of increasingly stringent energy requirements across Europe. When conventional district heating technology is used in areas with low energy consumption heatlosses do not fall even though the amount of energy delivered is reduced. This reduces income for thedistrict heating company. To maintain their economic viability the district heating companies? majorchallenge is to implement new solutions that minimize heat loss.

Humidity problems and poor ventilation are factors that we associate with poor indoor airquality which are known to negatively affect health. Such problems have decreased with timein Sweden but, in other countries this is still a major problem especially during winter. InChile, this is most common in the central regions of the country, especially the Strait ofMagellan. This issue is primarily due to surface condensation happening indoors which bringsabout dampness which facilitates the growth of fungus and stains, foul odors, metal corrosionand more. This is due to a combination of poor ventilation and insufficient forms of heatingalong with buildings which have no insulation.

Today the human being see energy as a matter of course but the resources that is used for extract energy is today not enough for the world demand. Of all the energy that is used in Sweden today approximately 40 % goes to the building stock. This number will most likely increase if not necessary actions will be made on the already existing building stock since new houses constantly are built which will be added up on the already existing energy supply. This takes cause of action on the already existing building stocks, to fulfill the demands of the future use of energy that has been set by the authority. At the same time the thermal conditions cannot be influenced by the necessary changes that must be made.

The housing sector uses 40 % of the energy in Sweden and half of the electricity usage. Theuse of energy is the main reason to the increasing rate of carbon dioxide in the atmosphere.This is the main motive but also a wish of higher safety, that is a higher rate of selfsufficientenergy production in Sweden, we want to decrease the need of using fossil fuel. Now whenthe energy price rise, the interest in energy issues increase and more people discuss thepossibility of reducing the usage of fossil fuel. A change to renewable energy such as sun,wind and water is the only solution where we can get a sustainable development.One way to contribute to a better use of energy is to build in the principle of passive house.The house is being built with a thick and tight insulation. If you use a heat-exchanger withhigh degree of efficiency and a final heating battery on the ventilation system, the heat fromlamps, devices and the ones living in the house should be enough to fulfil the criteria ofliving.

Long transport of products is an environmental issue discussed to an increasing extent. The consumers are increasingly aware of how far our comestibles really have been transported. The increasing levels of environmental emissions are something that concerns people. The question is nevertheless delicate and many choose to ignore it. This is no longer an option.

A third party access to district heating networks has been proposed in Sweden, to increase the competition on the district heating market. Such third party access could create opportunities for the agricultural sector as an energy producer. This study describes the technical, economical and environmental prerequisites for a farmer cluster to build and run a heating plant, fueled with local wood fuel. The heating plant in the described scenario is 8 MW and will supply a village of 1000 houses, and is fueled with wood chips exclusively. Supplying a heating plant with fuel puts high demands on the logistics, since there need to be a continuous flow of fuel. In the scenario, wood residues from felling and thinning is stored in stacks in the forest, and a few times a year chipped and transported to a storage area at the heating plant. In the study, an estimation of the profitability has been made by estimating the cost of the investment, personnel, operating and maintenance costs and costs for the fuel and ash handling.

The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation.The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion.Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE.

This thesis considers the use of an oldrock cavern as thermal energy storage.With a large system of differentchillers a model was created to find anappropriate future system. There aremainly two trajectories to take. Eitheran installation of chillers needs to bemade or the rock cavern can be used tomeet the future demand of districtcooling in Solna, Sweden. Additionallythis thesis investigates the possibleuse of different techniques to utilizethe phase change energy of water.Simulation shows that it?s possible toutilize the phase-change energy of afluid; however it?s not economicallyfeasible due to the thermodynamiceffects on the Carnot cycle.

Today, about 15 to 20 percent of Sweden?s total emission of carbon dioxide can be traced to the household sector. By examining apartment blocks in a life cycle perspective, the origin of the carbon dioxide emission has been charted and analyzed. This information has been used to create a computational model that calculates the total emission of carbon dioxide from a specific apartment block. The results from the analyzed apartment blocks indicate that both the use of energy and the emission of carbon dioxide have been reduced since the 1960s. Through the examination of building materials, it is possible to lower the emission of carbon dioxide that origins from the construction phase of an apartment block.

The purpose of this project is to analyze earthing systems for houses. By practical measurements and theoretical analyzes consequences of possible faults, that can occur within the facility and in the low-voltage distribution network, is illustrated.  The reason for this project is that nowadays one has to arrange with a main equipotential bonding system for buildings. Apart from that, if necessary, bathrooms must be provided with a supplementary equipotential bonding system.The practical measurements verify that potential differences in facilities may be due to voltage drops in the PEN conductor between the origin of the electrical installation and the power transformer.Based on the theoretical analyzes of possible faults, it is considered that the requirement for  supplementary equipotential bonding systems for bathrooms in most cases can be questioned, when basic insulation, fault protection, residual current devise and main equipotential bonding system already provides an adequate level of protection.A PEN conductor loss may result in a situation where metallic parts attached to the equipotential bonding system starts working as earth electrodes. Equipotential bonding system may also increase the incidence of stray currents. If TN-C-S systems is provided with a local connection to earth a redundant system against PEN conductor loss is obtained.

District heating covers around 80 % of the heating demand in apartment buildings and 10 % in single-family homes in Sweden. In the year 2010 the total input of energy to the Swedish district heating grids was about 70 TWh, which corresponds to 11 % of the total energy input to the whole energy system in the country. Through the combined production of heat and power the CHP-plants often reaches an efficiency of 90 % from energy in the fuel to produced heat and power. In order to keep the efficiency high it is important for the owners of the plant to have good knowledge about the plants performance at different operation points. Strängnäs Energi AB initiated this diploma work together with FVB Sverige ab in order to come up with a program for short term planning of the production of heat and power at the company´s CHP-plant.The work consists of three main parts.

Finnhamn is a small group of islands in the Stockholm archipelago. At Stora Jolpan, the biggest island, there is a hostel. The main building was built in 1915 and is called Utsikten. The purpose of this project is to on behalf of the Archipelago Foundation (Skärgårdsstiftelsen) find alternative systems that can replace the existing Heating system of Utsikten (an oil-fired boiler and electricity heaters) to a system with renewable energy. The alternative system that this project focuses on is a system of solar collectors combined with a wood chip boiler.

This examination work brings up opportunities to invest in a construction for heating with grain or pellets on farm level. As example we have chosen Fröberga Gård which is a farm located in Östergötland outside of Söderköping. The farm`s residential buildings is to day heated with oil and electricity. The result of our investigation shows that heating with grain is the best alternative, partly because of economical issues but also because you can grow the grain on your own farm and by that you can get better economy in your seed cultivation. To grow 16 tonne of grain as is needed demand gives a insignificant increase of work. Further an advantage is that no investment in machines is needed because all the machines witch is needed already is in use on the farm. In a situation where a new investment is needed as in the case we studied, is it often profitable to invest in a integrated furnace. Because all the components are well adapted to each other, and because that gives a high efficiency. If you already own a well working furnace is it often most profitable to connect a burner to it. It is important to know that heating with grain need more work than heating with pellets, because the high contents of ash in grain. Even if you choose pellets instead of grain the calculation shows good results. Because peat is an excellent but fairly untested raw material for pelletsproduction we have chosen to watch little more on its quality and conductions. We discovered that peat has a high heating value which makes it possible to raise the heat value in pellets through mix up peat and wood. Or you can make pellets with only peat and get a pellet with high heating value. Even the calculation with peatheating shows good results..

Uppsala County has ambitious environmental aims for the planned residential area inÖstra Sala backe. In this thesis different energy sources have been evaluated todetermine which system that would be most favorable given currently availableinformation about the project. Planned energy usage has been divided into tap waterheating, space heating and power. Three base case scenarios were made with districtheating, small scale bio fuel and heat pump. Solar power and solar heating were thensimulated and the production from the two could individually be deducted from theenergy need in the base cases, constituting 9 different scenarios.

The guest harbor on Utö, Utö Gästhamn, is currently using electricity for heating all of the water used in the showers and taps. Because of the large amount of visitors, especially during the summer months, the hot water usage gets very high and that is also the case for the electrical bills. During the year of 2011 the cost of electricity for Utö Gästhamn reached a total of 257 500 kr. Out of these 257 500 kr approximately 142 000 kr, 55 % of the total cost, were because of the water heating.The report is the result of a cooperation with Skärgårdsstiftelsen, the Green Islands-project and Utö Gästhamn where the mutual goal is to dimension a solar energy system, to promote the sustainable development.Initially the different techniques for the solar energy system are researched. The techniques are plane solar collectors, evacuated tube collectors, pool collectors and photovoltaic cells.