Energy consumption for heating and ventilation of buildings is still in 2011considered far too high, but there are many ways to save energy and construct lowenergy buildings that have not been fully utilised. This doctoral thesis has focused onone of these - low temperature heating systems. Particular attention has been given tothe ventilation radiator adapted for exhaust-ventilated buildings because of itspotential as a low energy consuming, easily-operated, environmentally-friendlysystem that might also ensure occupant health and well-being. Investigations were based on Computational Fluid Dynamics (CFD) simulations andanalytical calculations, with laboratory experiments used for validation. Main conclusions: Low and very low temperature heating systems, such as floor heating, in general createan indoor climate with low air speeds and low temperature differences in the room, whichis beneficial for thermal comfort. A typical disadvantage, however, was found to beweakness in counteracting cold down-flow from ventilation air supply units in exhaustventilatedbuildings. with ventilation radiators, unlike most other low temperature systems, it was found thatthe risk of cold draught could be reduced while still maintaining a high ventilation rateeven in cold northern European winters. ventilation radiators were found to be more thermally efficient than traditional radiators. design of ventilation radiators could be further modified for improved thermal efficiency. at an outdoor temperature of -15 °C the most efficient models were able to give doublethe heat output of traditional radiators. Also, by substituting the most efficient ventilationradiators for traditional radiators operating at 55 °C supply water temperature, it wasfound that supply water temperature could be reduced to 35 °C while heat outputremained the same and comfort criteria were met. lowering the supply water temperature by 20 °C (as described above) could givecombined energy savings for heating and ventilation of 14-30 % in a system utilising aheat pump. supply water temperatures as low as 35 °C could increase potential for utilising lowtemperature heat sources such as sun-, ground-, water- or waste-heat. This would beparticularly relevant to new-built “green” energy-efficient buildings, but severaladvantages may apply to retrofit applications as well. Successful application of ventilation radiators requires understanding of relevant buildingfactors, and the appropriate number, positioning and size of radiators for best effect.Evaluation studies must be made at the level of the building as a whole, not just for theheating-ventilation system. This work demonstrated that increased use of well-designed ventilation radiatorarrangements can help to meet regulations issued in 2008 by the Swedish Departmentof Housing (Boverket BBR 16) and goals set in the Energy Performance of BuildingsDirective (EPBD) in the same year. / QC 20110328 / STEM Projektnummer:30326-1 Energieffektiva lågtemperatursystem i byggnader

Feedback is an essential part of the software delivery process. Software metrics, as feedback, can give knowledge about the essential parameters that affect the software development process. An improved understanding of the software development process can facilitate more effective software management. With new software development methodologies emerging, such as Continuous Delivery, new information needs arise. The new methodology requires a new way of thinking when designing and developing dashboards for software development. A dashboard is a communication tool that can provide up-to-date information through at a glance interaction. The purpose of this thesis was to investigate how different software metrics related to Continuous Delivery can be visualized in a dashboard system at the company Saab. This thesis used a user-centered approach to find the appropriate visualization and user context to provide the user with feedback that supports the software development. The thesis work included user observations in the form of interviews and contextual inquiry. Thereafter, prototyping and usability testing were conducted in two iterations to design the dashboard and gather feedback. The result of this thesis work was a final prototype that was implemented in the program Kibana using real-time data from a software project. This thesis presents a set of elements that should be included when designing a dashboard for software development based on the findings of this study. / Feedback är en av de essentiella byggstenarna i en mjukvaruleveransprocess. Med mätvärden för mjukvaruutveckling kan organisationen få en större kunskap om de väsentliga faktorerna som påverkar mjukvaruutvecklingen. En ökad förståelse kan leda till en mer effektiv hantering av mjukvaruutveckling. Med nya metoder inom mjukvaruutveckling, t.ex. Continuous Delivery, som betyder kontinuerlig leverans, förändras behovet av feedback och nya utmaningar uppstår. Den nya metoden kräver nya uppläggningar vid utformning och utveckling av informationsradiatorer, en typ av kontrollpanel för mjukvaruutveckling. En kontrollpanel är ett kommunikationsverktyg som kan bidra med aktuell information om situationen genom att ge en överblicksbild. Målet med denna uppsats var att utreda hur mätvärden för mjukvaruutveckling kopplade till Continuous Delivery kan visualiseras på en kontrollpanel på företaget Saab. Detta examensarbete använde en användarcentrerad metod för att undersöka de vilka visualiseringar var lämpliga att använda och i vilken kontextanvändarna ville ha feedback. Examensarbetet utförde användarobservationer i form av intervjuer och kontextuell utredning. Sedan gjordes prototyper och användbarhetstestning. Detta gjordes i två iterationer för att samla in feedback och designa den slutgiltiga prototypen. Den prototypen utvecklades i programmet Kibana och använde realtidsdata från ett projekt. Resultatet i denna uppsats är ett förslag på vilka element som borde tas i hänsyn när en ska designa en kontrollpanel för systemutveckling.

Microchannels have been used in electronics cooling and in air conditioning applications as condensers. Little study has been made in the application of microchannels in automotive heat exchangers, particularly the radiator. The presented research captures the need for the design improvement of radiator heat exchangers in heavy-duty vehicles in order to reduce aerodynamic drag and improve fuel economy. A method for analyzing an existing radiator is set forth including the needed parameters for effective comparisons of alternative designs. An investigation of microchannels was presented and it was determined that microchannels can improve the overall heat transfer of a radiator but this alone will not decrease the dimensions of the radiator. Investigations into improving the air-side heat transfer were considered and an improved fin design was found which allows a reduction in frontal area while maintaining heat transfer. The overall heat transfer of the design was improved from the original design by 7% well as 52% decrease in frontal area but at the cost of 300% increase in auxiliary power. The energy saved by a reduction in frontal area is not substantial enough to justify the increase of auxiliary power. The findings were verified through a computational fluid dynamic model to demonstrate the heat transfer and pressure drop of microchannel tubes. The results confirmed that heat transfer of microchannels does improve the thermal performance of the radiator but the pressure drop is such that the net benefit does not outweigh the operating cost. An additional CFD study of the new fin geometry and air-side heat transfer predictions was conducted. The results of the study confirmed the theoretical calculations for the fin geometry.

This degree project cover renovation of sanitary rooms with focus on an exchange from a radiator system to an underfloor heating system out of the three aspects energy, moisture and thermal comfort. The used method is literature study, interview, case study and calculations. When a radiator system is replaced with an underfloor heating system the energy demand will decrease due to a possible temperature reduction. The power requirement for the bathrooms will be reduced if the finish material have a higher density and the volume of the room is small. The moisture aspect can in some cases deteriorate with the replacement of systems. It is possible to achieve the same thermal comfort with any system, but it is easier to adjust with an underfloor heating system. An exchange from a radiator system to an underfloor heating system is possible. The energy and thermal comfort aspects improves, but the moisture aspect will potentially degrade.

Uppvärmningen av ett småbostadshus står vanligen för kring hälften av dess energianvändning. Enligt energimyndigheten drar det svenska standardhuset 22,7 MWh per år varav 12,2 MWh går till uppvärmning. Att ge värmesystemet så bra förutsättningar som möjligt bör alltså vara av intresse för varje husägare, kanske främst ur ett ekonomiskt perspektiv men även ur ett ekologiskt perspektiv. I detta arbete har olika energieffektiviseringsåtgärder studerats som kan implementeras i en tvåplansvillas värmesystem bestående av en värmepump, golvvärme på nedervåningen och olika värmedistributionssystem på övervåningen. Åtgärderna har innefattat både praktiska såsom val av isolering i golvvärmesammanhang och mer teoretiska såsom reglerstrategier. Relevant teori för de ingående systemen har presenterats och utgjort grunden för implementeringar av systemen i simuleringsprogrammet IDA Indoor Climate and Energy. Programmet har använts för att simulera en modellbyggnad utrustad med de olika systemlösningarna varvid resultaten sedan jämförts mot varandra. Det mest energieffektiva systemet på övervåningen har visat sig vara lågtempererade radiatorer tack vare kombinationen med golvvärme på nedervåningen vilket tillåter värmepumpen att arbeta med en lägre värmekurva. Även då golvvärme på övervåningen användes erhölls en låg energiförbrukningen, dock på bekostnad av komforten. Elradiatorer, vilka inte kan utnyttja energin som värmepumpen hämtar ur värmekällan, gav den högsta energiförbrukningen. / Heating of a single family residence usually constitutes about half of the total energy consumption. According to Energimyndigheten, the average Swedish house consumes 22,7 MWh whereof 12,2 MWh goes to heating. To bring about as good conditions for the heating system as possible should be of interest for every house owner, maybe mostly out of an economic point of view but also out of an ecologic point of view. This work have studied different efforts aiming towards a more energy efficient system that can be implemented in the heating system of a two story single-family house equipped with a heat pump, floor heating on the first floor and different heat distribution systems on the second floor. The different efforts include both practical such as choice of insulation in relation to floor heating and more theoretical such as control strategies. Relevant theory for the different subsystems has been presented and used for implementation in the simulation software IDA Indoor Climate and Energy. The program was used to simulate a building model equipped with the different heating systems in which the results are compared to each other. The most energy efficient system on the second floor proved to be low temperature radiators due to the combination with the floor heating system on the first floor which allows the heat pump to operate with a lower heating curve. Although floor heating on the second floor also yielded a low energy consumption, it was at the expense of comfort. Electric radiators, which cannot take advantage of the energy the heat pump collects from the heat source, yielded the highest energy consumption.

The diploma thesis is focused on the research of dynamics of selected heating surfaces behavior. The aim of the thesis is to determine the dynamics of heating and cooling and to determine the effect of these characteristics on energy consumption of the building. The project part deals with the design of a heating solution for a residential building in three variants. An Energetic simulation is made for the designed variants, that compares the consumption of thermal energy during one year. The next simulation research the dynamics of selected large-scale heating surfaces. For each construction, nonstationary models of heating up and cooling were made, which are compared in terms of the thermal inertia.

This semestral thesis focuses on the description of specific renewable resources in the form of thermophotovoltaic cells using selective radiators with micro/nano structures. This work deals with an introduction of renewable resources and specifically focuses on thermophotovoltaic. Thesis describes basic principles, but also influences affecting the proper functioning of these systems. It also focuses on selective radiators, which are created by mikro/nano structures, and factors that can affect their implementation or simulation. Part of the work are also examples of calculations of basic parameters of the structures, which will be used in the simulations. Next chapters are dealing with simulations which are analyzing thermal effects on termophotovoltaic system. Except the analysis itself there is also partial optimalization solving some of the negative thermal effects.

The introduction of theoretical part deals with issue of fuel. There are basic kinds of fuels, their properties and calorific values. In next part a summary of types of boilers depending on the kind of fuel is described. A process of burning in each type is discussed. Then the basic issue of heat transmission, heat losses and design of individual elements of central heating system is described. In the second part there are two studies compared to each other. In the first one an automatic pellet boiler is used as a source of energy and in the second one it’s a heat pump, type air-water. At the end both of the variants are reviewed and the better option is chosen. In the last part the better option is designed, into detailed design documentation. Important design values for using the heating system and hot water service are calculated.

This diploma thesis deals with a design layout of the fan power supply that ensures the increase of the efficiency of the heating unit. For usage in the areas without electric power, the power supply is secured by thermoelectric generator. The system has to function on the basis of autonomous system which turns itself on only when necessary. In the introductory part of the paper there is a recherché of thermoelectric generators for general usage. Next it mentions the basic findings in from the field of DC/DC converters for low power applications. In this part attention is given to MPPT algorithm. Furthermore basic knowledge from the field of heat transmission together with its most used elements is described. Subsequently existing applications that increase the effectiveness of heating are mentioned. Their disadvantage however is that they depend on the external source of power supply. The practical part to a large extent covers the analysis of the suitability of the chosen thermoelectric module. For securing of the heat gradient of the generator there was a model created meeting the figures in the manual and there are several simulations in the MATLAB program. Furthermore several measurements of the thermoelectric module took place in order to secure realistic figures. Subsequently a DC/DC converter was chosen. Finally the testing was made on the real composition. In conclusion there is an overall evaluation including the real usage and the economical aspect of the project. The outcomes of the work enable to avoid common mistakes that are part of many specialized articles. The created system is to be used after the adjustment of the cooling to the required aim. At the same time it becomes very effective.

This Master’s thesis deals with design of heating source and heating system in the model object. Design is based on three variants of sources and heating systems. The first option is a heating pump air/water, the second option is pellet boiler and the third option is heating pump ground/water. At first heating losses are determined. Then heating systems and related heating sources are designed. The fundamental part of these free options is a design of alternative source for central heat and and hot water and heat storage. The last part is comparison of all variants.