AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

People in today?s society are becoming more and more aware of how important it is to use energy as efficiently as possible. This is clearly noticeable by an increase in home produced heat with e.g. solar panels or heat pumps heating systems. These changing customer demands forces district heating technology to be redesigned, which is why there is an ongoing research regarding the next generation of district heating - low temperature district heating (LTDH).

This report was performed in order to evaluate a new technological measure and focuses generally on a heat pump system to a HWC-washing machine. The client is Asko Appliances AB, a company well known for its environmentally friendly products. The goal of this study was to improve the energy efficiency of a washing machine by combining a heat pump device to the heater of the wash water, in order to reduce the energy consumed for heating the water. Besides reducing the energy consumption in heating the water, the washing machine was required to meet low noise and short operating time specifications. For that purpose, nine trials in three test series have been carried out.

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.

In cooperate with Asko Cylinda we have developed a new heat system too short the processtime and reduce the energy consume in a dishwasher and still have it too be a class AAA.The environment and quality is important for the company too still be the number one onthe market, If they want too keep that position the product developed of new innovations willbe very important. The systems we have developed are more effective and reduce energy uptoo 25 %. The process time is reduced too less than two hours, from the today two andhalf-hour. The solutions are too heat up the rinse water and the dishwater at the same time,with a new heating system and it make are solutions unique and effective. Its good for thedish and the environment.

AbstractEmbla 5 is an office building which has done a large improvement. The clients of this building has made an order of WSP and the student Anders Kempe to calculate the use of energy for the building, and after that result proposing further measures which can decrease the energy use of Embla 5.The ground for this report is when calculation of the present energy use of the building is stated. To make that information of a number of parameters such as envelope, the heating system and ventilation has been located and set in to the simulation program IDA ICE which calculate the energy use.To improve the energy use further this project has been concentrated to change the system of ventilation. Today the ventilation system is of the kind CAV (constant air volume) and the air flow is dimensioned for after recommendations from BBR and Arbetsmiljöverket in the office spaces. Consider that Embla 5  is an office building where the people only staying for 8-10 hours/day so was the ide to see how much energy saving if the air flow is reduced the time people not being in the building.

Vattenfall Heat Uppsala runs the waste incineration plant in Uppsala, which produces district heating, process steam, district cooling and electricity. Vattenfall Heat Uppsala has decided to introduce an energy management system with the aim to increase the energy efficiency of the plant. The basis in such a system is to make an energy mapping.In this thesis an energy mapping has been performed at the waste incineration plant with the aim to identify and determine the size of energy flows. The investigated energy flows are used fuel, produced and used steam, produced district heating and cooling. Also the use of electricity to run the processes has been investigated.

The purpose with this report is to examine how the implemented energy efficiency measures on Bokelundskolan in Växjö have had impact on the energy use. The measures which have been implemented are, new ventilation system, new heating system, optimized adjustment of the heating system, new windows with U-value 1.2 and lower window height, insulation under windows and in the crawl space. The school's energy use before and after rebuilding has been calculated with the calculation program, Vip-Energy 1.5.5.Calculations of energy use for the school with windows on U-value, 0.9 and 0.7 have also been done. The replacement of windows has been studied from a cost perspective. The conclusion is that the exchange of heat and ventilation system was the biggest contributor to reduced energy use on Bokelundskolan.

AbstractThis thesis examines and discusses a sample of the medieval hypocausts (stone-heating ovens) in the Baltic area. The medieval construction is thoroughly explained as well as the antique hypocaust in order to establish a base for the following discussion. The medieval hypocaust has been almost forgotten for a long period of time. The last time someone dealt with this category of finds were in the 1960?s by Swedish archaeologist Iwar Andersson and in the 1970?s by Danish archaeologist Johannes Hertz.

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.

pelago. There is an old inn that is located on the island that has become a very popular attraction in the last couple of years. The inn has both a well-known restaurant as well as conference facilities that are used by tourists as well as the people of Stockholm over the summer months. The inn was built 1908 and has since remained in the same condition.make islands in the archipelago more environmentally friendly and promote sustainability. One of their project islands is Grinda.

Passive houses are a relatively new concept in Sweden and by that it is meant a house without a traditional heating system. The most acknowledged passive house project is the terrace houses in Lindås, Gothenburg, which we have used as a reference. This project concerns a square apartment block. So far, no square apartment block has been built as a passive house in Sweden.The common opinion in the construction industry is that it is not economical to build extremely energy efficient houses. With Peab as commissioner our task was to investigate if that is true, if regarding the construction of a multi storey house as a passive houseMidroc, now owned by Peab, constructed in the block of Preussen in Jönköping during 2004-2005 four houses, with 132 apartments distributed on seven floors.

Wavecraft AB develops medical equipment for heating of organic synthesises. The heating is done with microwaves, which improves the process in both speed and accuracy compared to the more traditional methods where heating elements are used. This report discusses the developement of an automatic lid mechanism for one of Wavecraft's product prototypes. The company assumes that the final product will be integrated by customers into fully automated systems, and the upgrade from a manually to an automatically controlled lid is therefore an important step in the product's developement process.The first stage och the project was an idea generation process. The ideas generated here were organized into five different concepts of which the best one was selected through the use of a concept matrix.

The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage.

The aim of this thesis is to develop a new business model for district heating and cooling firms which can contribute to a stabilization of the Swedish national energy system. The business model is developed for a district heating and cooling firm and is exemplified with Fortum Heat. The theoretical investigation around the topic creates a rigid base for following qualitative empirical studies. Osterwalder?s canvas for business model generation is used together with a Casual Loop Diagram to identify a number of business opportunities which stabilizes the national energy system.