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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Thermal efficient dwelling design, Bali, Indonesia

Trimarianto, Ciptadi January 2003 (has links)
In the warm humid tropical climate of Bali, Indonesia, overheating and high humidity influence occupants' comfort, indoor climate and the comfort of their homes, both directly and indirectly. The traditional way to deal with these problems, using natural ventilation, was ecologically sound and acceptable. However, development of tourism in Bali has had a positive impact on people's earning, causing cultural pressure, migration and a rapid rise in the urban population, as well as increasing housing demand. In urban areas, the methods of climate modification have moved away from natural ventilation, and comfort is now more often achieved by installing air conditioning. This has caused increasing energy use and had economic impact. As world-wide energy consumption will continue to increase, the use of more energy will have more impact on global warming. In these circumstances, energy efficiency is paramount, particularly in the dwelling designs for new housing development in Indonesia. The study focuses on the design of a thermally comfortable dwelling in the warm humid climate of Bali, Indonesia, with emphasis on the energy efficiency of the naturally ventilated and air-conditioned dwelling. Using a computer program and energy conservation strategies, a dwelling design was simulated. A model dwelling was adopted from a standard house type for people on a middle class income, based on the family size of a couple with two children. Such units are built by the National Housing Authority of Indonesia. A comprehensive study of the computer-simulation outcomes, survey research, previous works undertaken and literature reviews were carried out, to develop a thermally comfortable dwelling design. This new thermally efficient dwelling design was simulated to draw the final conclusions of the research. The research discovered that the combination of both natural ventilation and air conditioning, integrated with the combined design of a compound-compact dwelling, are an intelligent response to the thermal comfort performance problems of a dwelling in the warm humid climate and architecturally adaptable to the culture of Bali. The study found that a combination of natural ventilation with air conditioning which is only used when necessary, coupled with insulation and shading devices, can significantly reduce energy consumption and achieve adequate thermal comfort. In this respect, however, architectural design should come first, and be considered before an engineering solution. The reasons are that architectural solutions are more robust, and has a long duration of applicability, while the technology is perhaps the opposite, being prone to mechanical failure. When a less compact dwelling is designed, increased use of natural ventilation can be achieved. The use of airtight construction, insulation in the building envelope and shading devices are effective ways of reducing the air-conditioning load.
2

Technique and human perception of intermittent air velocity variation

Wigö, Hans January 2005 (has links)
<p>Objectives. The main objective of the present thesis was to evolve a controlled intermittent velocity field and to examine the impact of this type of dynamic indoor climate on human’s psychology and physiology. The prediction was that intermittent velocity variation could provide occupants with the desired cooling without causing draught and that this intermittent change of the indoor climate would influence peoples’ affect and cognitive performance.</p><p>Methods. All experiments were performed in a classroom-like environment where groups of subjects were exposed to a temperature increase and step changes in air velocity. The changes or intermittent variations in air velocity consisted of elevated speed during five minutes, which were repeated three times. To reduce the influence of individual thermal preferences all measures were collected twice and the statistical analyses were based on the change scores in these measures.</p><p>Results. The obtained results showed that, intermittent velocity variation may provide occupants with the desired cooling without causing draught. Subjects exposed to velocity variations were significantly less affected by the temperature rise in the room, compared to the control group. Moreover, the method reduced the expected increase of occupants who perceived the temperature condition as uncomfortable. The findings concerning air movements demonstrate that very few perceived the condition as draughty, after being exposed to the three high velocity pulses.</p><p>The results concerning affect showed a significant effect on high activation, in the temperature range 21 - 24<sup>o</sup>C when the velocity variations made the subjects rate the temperature as slightly lowered over time, they kept their level of activation. In the higher temperature interval, 25 - 27<sup>o</sup>C, unactivated unpleasantness increased and activated pleasantness decreased significantly more in subjects in the constant velocity condition than it did for subjects in the velocity variation condition. In sum, all results concerning affect, the significant ones and tendencies point in the same direction. Subjects exposed to velocity variation report changes, over time, indicating higher activation and more positive feelings.</p><p>No differences in cognitive performances were shown between the air velocity conditions. However, a tendency to a significant result (p = 0.10) in an attention task was shown, indicating that subjects in the velocity variation condition increased their speed in a short-term memory search, compared to subjects in the constant velocity condition.</p><p>In the temperature range 21- 24<sup>o</sup>C, where the perception of the room temperature was measured at 0, 5 and 10 minutes respectively after the last high velocity period, the difference in MTV scores between the two groups, did decrease over time. Ten minutes after the last pulse the difference in MTV scores between the two groups was not significant. This suggests that the high velocity period should be repeated every10 to 15 minutes to keep the expected rise in subjects who judged the thermal conditions as uncomfortable down.</p><p>The skin temperature was not affected neither by the rise in ambient temperature (from 21 to 24<sup>o</sup>C over 80 minutes) nor the periods (3 x 5 minutes) of high velocity. A consequence of this result is that the human temperature regulation system permitted an increased heat loss during the high velocity pulse, and hence a reduction of the body’s internal stored heat. For uncovered body parts the increase in heat loss was 20 % during the high velocity pulse. Summarised over the whole exposure time the three pulses produced a total energy loss that was only 2 % higher compared to constant low velocity.</p>
3

Technique and human perception of intermittent air velocity variation

Wigö, Hans January 2005 (has links)
Objectives. The main objective of the present thesis was to evolve a controlled intermittent velocity field and to examine the impact of this type of dynamic indoor climate on human’s psychology and physiology. The prediction was that intermittent velocity variation could provide occupants with the desired cooling without causing draught and that this intermittent change of the indoor climate would influence peoples’ affect and cognitive performance. Methods. All experiments were performed in a classroom-like environment where groups of subjects were exposed to a temperature increase and step changes in air velocity. The changes or intermittent variations in air velocity consisted of elevated speed during five minutes, which were repeated three times. To reduce the influence of individual thermal preferences all measures were collected twice and the statistical analyses were based on the change scores in these measures. Results. The obtained results showed that, intermittent velocity variation may provide occupants with the desired cooling without causing draught. Subjects exposed to velocity variations were significantly less affected by the temperature rise in the room, compared to the control group. Moreover, the method reduced the expected increase of occupants who perceived the temperature condition as uncomfortable. The findings concerning air movements demonstrate that very few perceived the condition as draughty, after being exposed to the three high velocity pulses. The results concerning affect showed a significant effect on high activation, in the temperature range 21 - 24oC when the velocity variations made the subjects rate the temperature as slightly lowered over time, they kept their level of activation. In the higher temperature interval, 25 - 27oC, unactivated unpleasantness increased and activated pleasantness decreased significantly more in subjects in the constant velocity condition than it did for subjects in the velocity variation condition. In sum, all results concerning affect, the significant ones and tendencies point in the same direction. Subjects exposed to velocity variation report changes, over time, indicating higher activation and more positive feelings. No differences in cognitive performances were shown between the air velocity conditions. However, a tendency to a significant result (p = 0.10) in an attention task was shown, indicating that subjects in the velocity variation condition increased their speed in a short-term memory search, compared to subjects in the constant velocity condition. In the temperature range 21- 24oC, where the perception of the room temperature was measured at 0, 5 and 10 minutes respectively after the last high velocity period, the difference in MTV scores between the two groups, did decrease over time. Ten minutes after the last pulse the difference in MTV scores between the two groups was not significant. This suggests that the high velocity period should be repeated every10 to 15 minutes to keep the expected rise in subjects who judged the thermal conditions as uncomfortable down. The skin temperature was not affected neither by the rise in ambient temperature (from 21 to 24oC over 80 minutes) nor the periods (3 x 5 minutes) of high velocity. A consequence of this result is that the human temperature regulation system permitted an increased heat loss during the high velocity pulse, and hence a reduction of the body’s internal stored heat. For uncovered body parts the increase in heat loss was 20 % during the high velocity pulse. Summarised over the whole exposure time the three pulses produced a total energy loss that was only 2 % higher compared to constant low velocity. / QC 20111221
4

Heating regimes in Swedish churches c. 1880-1980

Legnér, Mattias, Geijer, Mia January 2012 (has links)
Cultural heritage and human comfort: The issue of indoor climate in historic buildings in the twentieth centuryI
5

Passive solar options for reducing heating demand and maintain indoor climate in a multifamily house in Sweden

Joubert, Andras January 2014 (has links)
This research was carried out by studying possible renovation of a two-storey detached multifamily building by using passive solar design options in a cold climate in Borlänge, Sweden where the heating Degree Days are 4451 (base 20°C). Borlänge`s housing company, Tunabyggen, plans to renovate the project house located inthe multicultural district, Jakobsgårdarna. The goal of the thesis was to suggest a redesign of the current building, decrease the heating energy use, by applying passive solar design and control strategies, in a most reasonable way. In addition ensure a better thermal comfort for the tenants in the dwellings. Literatures have been studied, from which can be inferred that passive design should be abasic design consideration for all housing constructions, because it has advantages to ensure thermal comfort, and reduce the energy use. In addition further savings can be achieved applying different types of control strategies, from which the house will be more personalized, and better adapted to the user’s needs.The proposed method is based on simulations by using TRNSYS software. First a proper building model was set up, which represents the current state of the project building. Then the thermal insulation and the windows were upgraded, based on today's building regulations. The developments of the passive solar options were accomplished in two steps. First of all the relevant basic passive design elements were considered, then those advantages were compared to the advantages of applying new conventional thermostat, and shading control strategies.The results show that there is significant potential with the different types of passive solar design; their usage depends primarily on the location of the site as well as the orientation of the project building. Applying the control strategies, such as thermostat, and shading control, along the thermal insulation upgrade, may lead to significant energy savings (around 40 %), by comparison to the reference building without any upgrade.
6

Tracing the Historical Indoor Climate of a Swedish Church, c. 1800-2000

Legnér, Mattias January 2012 (has links)
Kulturarvet och komforten: Frågan om lämpligt inomhusklimat i kulturhistoriska byggnader under 1900-talet
7

Inomhus- och arbetsmiljön i grund- och gymnasieskolan : En studie i Malå och Norsjö kommuner / Indoor environment in schools : a study in the municipality of Malå and Norsjö (Sweden)

Ohlsson, Ida January 2014 (has links)
The purpose of this study was to examine the school environment in the municipalities of Malå and Norsjö. The study focused on cleaning, ventilation, classroom noise and illumination which are the most important factors for a good indoor climate and a good working environment in school. The study was performed by inspection of school buildings, questionnaire among school children and measurements of CO2. The result showed that all the visited schools did not meet the Swedish standards for cleaning and ventilation, also sound environment and the illumination had inadequacies in some of the classes. The result also showed that the majority of the pupils were satisfied with the indoor climate and working environment. Of the total percentage of pupils surveyed, 35% of the pupils were unsatisfied with the cleanliness of the toilets and 44% reported that the sound level is perceived as disturbing. The measurements of CO2 showed that all schools had concentrations (ranging from 541-926 ppm) below the Swedish standard (1 000 ppm), nevertheless there was indications that these concentrations may increase during a day. In conclusion this study showed that the indoor environment in the visited schools had inadequacies which may have a negative impact of the pupils. To avoid unhealthy, and from a public health perspective, these inadequacies should be attended.
8

Numerical Study on Indoor Climate Using Single-Phase and Multiphase Models / 単相および多相場モデルによる室内気候の数値解析的研究

Chamika, De Costa 24 September 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19280号 / 工博第4077号 / 新制||工||1629(附属図書館) / 32282 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 牛島 省, 准教授 米山 望, 准教授 山上 路生 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
9

En byggnads energiprestanda : En utredande och jämförande studie av Boverkets författningssamling BEN1

Arnfelt, Emma January 2017 (has links)
This report is an exploratory and comparative study of Boverkets constitution BEN1. In this study the constitution BEN1 is examined, why the constitution was established, when is it applicable and what advantages and disadvantages will come with it. Today the housing and service sector is using a major part of Europe’s final energy use, in addition to this, these sectors also represents a major part of the total carbon dioxide emissions. The EU-commission aims to reduce the housing and service sectors energy use and emissions. In 2002 the European parliament established directives and demands for buildings energy performance. These directives were changed in 2009-2010, which led to an inspection of the already existing Swedish constitution, this was found to be inadequate by the EU-commission. Sweden decided to create a new constitution in order to satisfy EU’s new directives and demands. The focus is on a normal usage of the building in a normal year in the new constitution, BEN1.  The reader should receive an idea and understanding about BEN1 and why it was established in this report. Beyond this, the study will show the changes that happen to a buildings energy performance after the constitution is applied and what advantages and disadvantages this could bring.  This study was performed by simulating the buildings energy use with the input from BEN1 in a simulation tool, IDA Indoor Climate and Energy.  The study shows that the energy performance will change but it also shows that further studies should be made in order to obtain a more carefully drawn and common conclusion. / Detta är ett examensarbete på grundnivå (kandidatexamen), 15 högskolepoäng. Examensarbetet är en utredande och jämförande studie av Boverkets senaste författningssamling BEN1. I denna studie utreds BEN1, varför det upprättades, när det ska tillämpas och vad det medför i fråga om för- och nackdelar.   Idag utgör tjänste- och bostadssektorn en stor del av Europas slutliga energianvändning och totala koldioxidutsläpp, något som EU-kommissionen har som mål att minska. Minskningen skulle ske med tillämpning av Europaparlamentets direktiv och krav gällande energideklarationer som kom år 2002. Direktivet omarbetades under 2009-2010 vilket ledde till en granskning av det befintliga svenska regelverket, EU-kommissionen fann detta bristfälligt och beslutade därför om ett överträdelseförfarande. Sverige svarade på överträdelseförfarandet med den nya författningssamlingen BEN1 som handlar om fastställande av byggnaders energianvändning vid normalt brukande och ett normalår.  I denna rapport ska läsaren få en uppfattning om och förståelse kring Boverkets författningssamling BEN1 och varför den upprättats. Utöver det ska studien påvisa förändringarna som sker hos en byggnads energiprestanda vid tillämpning av BEN1 samt upplysa läsaren om vilka för- och nackdelar tillämpningen av BEN1 kan ge. Studien har utförts genom att simulera byggnadernas energianvändning, enligt BEN1s föreskrifter och allmänna råd, i IDA Indoor Climate and Energy, ett simuleringsverktyg. Studien visar att en byggnads energiprestanda kommer att förändras men att vidare studier bör göras för att en mer noggrann och allmän slutsats ska kunna erhållas. De största förändringarna gällande energiprestandan har skett i byggnadens behov av värme och varmvattenberedning, detta efter tillämpande av de schablonvärden BEN1 erhåller. Resultaten som erhålls i denna studie är enligt BEN1 validerade värden för byggnadernas energiprestanda.
10

Energihushållning och varsamhet för äldre byggnader : Chefsbostaden i Strömsholm, ett timmerhus från 1900-talets början

Ölander, Ylva January 2014 (has links)
This report is the result of a degree project in building engineering, at an advanced level. The project evaluated a building from a technical and historical point of view, and focused on its energy consumption, particularly the energy used for heating. The building in question was a small apartment building in Strömsholm, Sweden. It was made in 1902, from vertical logs, a not so common form of the traditional log house. The goal of the project was to evaluate if the energy consumption could be reduced in accordance with building preservation regulations, that is without damaging any of the building’s cultural or historical values. The building was surveyed with the help of archive and literature studies, interviews and inspections. Based on these findings, supplementary insulation on the inner side of the climate screen was decided on. The program IDA Indoor Climate and Energy was used to make computer simulations of the energy consumption of the building for five different alternatives of supplementary insulation. Part of the project was also to investigate whether IDA Indoor Climate and Energy was suitable for energy simulations of old buildings. The moisture balance of the outer walls was calculated manually to see if the supplemental insulation constituted a risk when it came to the moisture sensitivity of the construction. The result of the computer simulations, combined with building physics, shows that the energy consumption for heating could be reduced, especially if the roof was to be insulated. However, these results cannot and should not be seen as anything but indications, because of the uncertainty of the input data. The data on ventilation and air flows was considered to be one of the main sources of error. Furthermore, there were signs that the design of the computer models was far from optimal. The result of the moisture calculations shows that the moisture sensitivity is indeed increased. IDA Indoor Climate and Energy was judged as more suitable for simulations of new buildings than of old ones, due to the complexity of the latter, but the program can still be used as an aid for energy evaluations of old buildings if it is used in the right way. / Denna rapport är resultatet av ett examensarbete i byggnadsteknik på avancerad nivå. Arbetet gick ut på att undersöka en byggnad ur ett tekniskt och kulturhistoriskt perspektiv, med inriktning på hushållning av energi. Föremålet för undersökningen var ett flerbostadshus i restimmer, uppfört 1902 i Strömsholm, Västmanland. Målet var att undersöka om byggnadstekniska åtgärder behövdes för att minska energiåtgången, främst den för aktiv uppvärmning, i byggnaden. Dessa åtgärder skulle utformas så att byggnadens bevarandevärda särdrag inte går förlorade, i enlighet med Plan- och bygglagens bestämmelser om ändring av byggnader. Med hjälp av arkivsökningar, litteraturstudier, intervjuer och undersökningar kartlades byggnaden. Utifrån dess förutsättningar bestämdes förslag för energibesparande åtgärder, fem olika alternativ för invändig tilläggsisolering. För att beräkna byggnadens energiåtgång och hur mycket de olika alternativen skulle kunna påverka denna gjordes simuleringar i programmet IDA Indoor Climate and Energy. En av frågeställningarna i arbetet var huruvida detta program var lämpligt för energisimuleringar av äldre byggnader eller inte. Beräkningar av den relativa luftfuktigheten i ytterväggen gjordes för hand för att bedöma fuktskaderisken i konstruktionen efter tilläggsisolering. Indata till fuktberäkningarna och datorsimuleringarna hämtades från litteraturen eller utgjordes av uppskattningar. Resultat av datorsimuleringarna, tillsammans med byggnadsfysiska resonemang, visar att det går att minska energiåtgången för uppvärmning, driftel och tappvarmvatten, i synnerhet vid tilläggsisolering av taket. Dock kan inte dessa resultat ses som något annat än indikationer eftersom osäkerheterna i indata för modellerna var för stora. Bristande indata för ventilationen bedömdes vara en av de största felkällorna. Dessutom föreligger vissa reservationer gällande modellernas utformning. Resultatet av fuktberäkningarna visar att väggarna blir känsliga för fuktskador vid invändig tilläggsisolering. IDA Indoor Climate and Energy bedöms vara lämpligare för simuleringar av nyproducerade byggnader än av äldre byggnader på grund av komplexiteten hos de senare, men det kan ändå fungera som ett hjälpmedelvid energiutvärderingar av sådana om det används rätt.

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