The building sector alone accounts for almost 40% of the total energy demand and people spend more than 80% of their time indoors. Reducing energy demand in buildings is essential to the achievement of a sustainable built environment. At the same time, it is important to not deteriorate people’s health, well-being and comfort in buildings. Thus, designing healthy and energy-efficient buildings is one of the most challenging tasks. Evaluation of buildings with a broad perspective can give further opportunities for energy savings and improvement of the indoor climate. The aim of this thesis is to understand the functionality, regarding indoor climate and energy performance, of a low-energy building. To achieve this, a multi-dimensional approach is used, which means that the building is investigated from several points of views and with different methods. A systems approach is applied where the definition of the system, its components and the border to its environment, is essential to the understanding of a phenomenon. Measurement of physical variables, simulations, and qualitative interviews are used to characterize the performance of the building. Both energy simulation and computational fluid dynamic simulations are used to analyse the energy performance at the building level as well as the indoor climate at room level. To reveal the environmental impact of the low-energy building studied in this thesis the CO2 emissions and embodied energy have been investigated regarding different surrounding energy systems. The evaluated building is situated at the west coast of Sweden and uses about 50% of energy compared to a comparable ordinary Swedish building. The building is well-insulated and an air-to-air heat exchanger is used to minimise the heat losses through ventilation. The houses are heated mainly by the emissions from the household appliances, occupants, and by solar irradiation. During cold days an integrated electrical heater of 900 W can be used to heat the air that is distributed through the ventilation system. According to measurements and simulations, the ventilation efficiency and thermal environment could be further improved but the occupants are mostly satisfied with the indoor climate. The control of the heating system and the possibility for efficient ventilation during summertime are other important issues. This was found through quantitative measurements, simulations and qualitative interviews. The low-energy building gives rise to lower CO2 emissions than comparable buildings, but another energy carrier, such as district heating or biofuel, could be used to further improve the environmental performance of the building. The total energy demand, including the embodied energy, is lower than for a comparable building. To understand the functionality of a low-energy building both the technical systems and the occupants, who are essential for low-energy buildings, partly as heat sources but mainly as users of the technical systems, should be included in the analysis.

This dissertation presents experiments with the UVic Earth System Climate Model that explore the sensitivity of global climate simulations to an increase of horizontal resolution into the ocean eddy-permitting range. Model versions, with resolutions ranging from 1.8' (latitude) x3.6' (longitude) to 0.2'x0,4'. are evaluated in control states and in response to climate perturbations. The effect of resolution on ocean volume transport, ocean heat transport, water mass formation, and sea ice distribu¬tion are investigated within the framework of three foci: 1) the Atlantic meridional overturning circulation and its response to surface freshwater forcing: 2) the South-ern Ocean overturning circulation and its response to poleward intensifying winds concomitant with increasing atmospheric C02; 3) the Southern Ocean temperature and Antarctic Circumpolar Current response to poleward intensifying winds alone. These sensitivity studies shed light on the ability to draw firm conclusions from coarse resolution modelling results. First, it is found that the simulation of western boundary currents. sea ice and meridional heat. transport. in the North Atlantic Ocean are improved with increasing resolution. A slowdown of the Atlantic meridional overturning circulation is robustly produced at both coarse and ocean eddy-permitting resolutions in response to fresh-water forcing applied evenly over the Labrador Sea and exclusively along its western boundary. An evaluation of the forcing impact on different regions of NADW for-mation with tracers reveals that increased Labrador Sea deep convection at higher resolution may mitigate the influence of better resolved boundary current transport. With increasing resolution. there is less cooling in the subpolar west Atlantic. more cooling in the subpolar east. Atlantic, and greater variability in the deep ocean re-sponse to the western boundary forcing. Second, it. is found that as resolution increases the interior ocean circulation be-comes more adiabatic, with deep water formed in the North Atlantic tending to upwell more in the Southern Ocean and less in the low-latitude oceans. For some density classes the transformation rate derived from surface buoyancy fluxes can provide a proxy for the net meridional transport in the upper Southern Ocean. The response of the Southern Ocean overturning to poleward intensifying southern hemisphere winds concomitant with increasing atmospheric CO2 suggest that the circulation associated with the formation of Antarctic Intermediate Water is likely to strengthen through the 21st century. Third, the zonal mean structure of the Southern Ocean temperature response to poleward intensifying winds through the 21st century, with warming between 40-55°S and cooling at higher and lower latitudes. remains robust as model resolution increases. However, the migration of distinct ocean fronts at finer resolutions can produce a strong local intensification of the temperature response. There is also less high latitude cooling and a greater loss of sea ice thickness at eddy-permitting resolutions, in conjunction with a significant increase in southward ocean eddy heat transport. Antarctic Circumpolar Current transport is found to increase in response to the forcing at both coarse and eddy-permitting resolutions.

Made available in DSpace on 2017-07-21T14:19:32Z (GMT). No. of bitstreams: 1 AdrianoSerckumecka.pdf: 825262 bytes, checksum: 9c527c3f506be1e58cf82ac8117dac67 (MD5) Previous issue date: 2012-07-17 / The main objective of this work is the evaluation of distributed systems based on peer-topeer network and parallel computing techniques to reduce response times of climate simulations. A probabilistic model for simulating wind data was used and two computing applications was implemented and evaluated. The first application was developed by using the framework P2PComp, which is directed to building parallel software and its deploy in P2P networks. The second application was developed without the support of this framework and using straightly the communication infrastructure software. Climatic data of the municipality of Lapa, Paraná comprising the period between 1998 and 2007 were used in the experiments. The results demonstrate the feasibility of using parallel computing and P2P networks for executing climate simulations. Best results, measured by the speedup obtained, were observed when using multiple peers (equal to 26) and when executing simulations for a long period of time ( near to 100 years). In such case, the speedup obtained is near to 7. / O objetivo principal deste trabalho é a avaliação de sistemas distribuídos baseados em redespar-a-par (P2P), juntamente com técnicas de computação paralela, para reduzir os tempos deresposta de simulações climáticas. Um modelo probabilístico específico para simulação de dados de vento foi adotado e duas aplicações computacionais foram implementadas e avaliadas.A primeira aplicação foi desenvolvida com o uso do Framework P2PComp, que permite a criação de programas paralelos e sua execução em redes P2P. A segunda aplicação adotou diretamente uma rede P2P, sem o uso desse framework, como infraestrutura de comunicação.Dados climáticos da região do Município de Lapa-PR, compreendendo o períıodo entre 1998 e 2007 foram empregados nos experimentos. Os resultados obtidos demonstram a viabilidade de utilização de computação paralela em redes P2P, nas simulações climáticas. Os melhores resultados medidos em relação ao fator de aceleração foram observados em situações onde foi utilizado um número maior de pares (igual a 26) e simulações climáticas para um período de tempo igual a 100 anos. Para este caso, o fator de aceleração obtido foi aproximadamente igual a 7.

In arid countries both water scarcity and salinity represent the key factors which drastically limit crop yield in irrigated agriculture. In addition, relatively poor management practices with pretty low water productivity (WP) seriously aggravate the situation. In order to get “more crop per drop', i.e., to substantially improve water use efficiency, this thesis proposes the novel strategy NEMO (Nested Experimental, Modeling, and Optimization Strategy) for reliably evaluating an optimal irrigation schedule. The proposed methodology relies upon a close interaction between in-depth field investigations and physically based process modeling. It is tailored specifically to fit the requirements in resource-restricted regions. Comprehensive field experiments, on site measurements as well as various laboratory analyses provide a representative database for characterizing the relevant environmental parameters as e.g. the soil properties at the considered location and the prevailing climate. A substantial part of the data obtained from the field experiments provided the input for the internationally recognized SVAT software DAISY1 or APSIM2, both physically based irrigation models which have already been successfully applied in arid regions. APSIM - which is used in the advanced parts of the study - includes not only a process based model for soil moisture transport but also a plant physiological model which describes the plant behavior under specific irrigation scenarios for a selected crop throughout a growing season. The adaption of the irrigation model to local conditions and its preliminary parameterization firstly follows available guidelines and data for areas with similar climate and soil conditions. Reference data and deterministic weather data served to build up DAISY’s basic model files. DAISY is then used within the framework of the custom made and problem oriented optimization software GET-OPTIS for evaluating the corresponding optimal irrigation schedule for a first preliminary series of experiments (IrrEx1). A second series of field experiments (IrrEx2) was accompanied by transient soil moisture measurements, which served for evaluating the soil hydraulic parameters, while the obtained yield was used for calibrating the plant physiological model of APSIM. Taking still into account the stochastic nature of weather phenomena, a stochastic optimization with GET-OPTIS was then applied not only for the traditional full irrigation but also for the most important deficit irrigation and the irrigation with saline water. The obtained optimal irrigation schedules are subsequently used for a final series of rigorous irrigation experiments (IrrEx3) which specifically focused on: (1) full irrigation for high yields with most economic water application, (2) deficit irrigation aiming at a maximum yield with only a limited amount of irrigation water, and (3) full irrigation with saline irrigation water for maximum yield. At the harvesting time, the observed crop yield and the water productivity were compared - together with other plant characteristics - with the corresponding calculated values. The agreement between calculated and measured crop data was excellent. All the field experiments have been performed following a parallel use of the common traditional FAO class A-Pan method and the novel NEMO technology. Based on the outcome of the field experiments, the NEMO applications demonstrated a striking superiority throughout all scenarios as compared to the FAO method as regards economic efficiency and sustainable use of irrigation water in both aspects water quantity and salt accumulation. Contrary to common practice, the optimal NEMO irrigation schedule - which relies on stochastic weather data - has an extended validity. Together with the use of physical data and adequate process models, the developed methodology features a highly promising potential for generalizing the experimental findings for other, environmentally similar, regions. NEMO thus opens wide possibilities for a cost effective and sustainable long-term application to other arid or semi-arid areas.

Made available in DSpace on 2017-07-21T14:19:39Z (GMT). No. of bitstreams: 1 Ciro Baron Neto.pdf: 1513768 bytes, checksum: a9f4624d5d9521cfa109fa40a688cbb2 (MD5) Previous issue date: 2014-02-28 / This paper presents an approach of technologies GPGPU (General-Purpose Computing on Graphics Processing Unit) and P2P (peer-to-peer) networks in order to improve the response time of climate data simulations. Thus, an application using CUDA (Compute Unified Device Architecture) architecture and the simulation model of Venthor simulator were initially adopted and integrated into the P2PComp framework. The results indicate an acceleration factor equal to 70 for single computers. Furthermore, the possibility of using a P2P sharing network for processing, higher acceleration factors can be obtained. Computer simulation models usually demand high processing power and this work showed that the use of parallelism in GPUs and P2P networks is an alternative that allows better performance when compared to sequential computing. / Este trabalho apresenta uma avaliação das tecnologias de GPGPU (General-Purpose Computing on Graphics Processing Unit) e de redes P2P (peer-to-peer) para melhorar o tempo de resposta de simulações de dados climáticos. Para isso, uma aplicação utilizando a arquitetura CUDA (Compute Unified Device Architecture) e o modelo de simulação de dados de vento do software Venthor foram inicialmente adotados e após integrados ao framework P2PComp. Os resultados indicam um fator de aceleração igual a 70 para computadores isolados. Além disso, com a possibilidade do uso de uma rede P2P para compartilhamento de processamento, fatores de aceleração maiores podem ser obtidos. Modelos de simulação computacional geralmente demandam alto poder de processamento e este trabalho mostrou que a utilização do paralelismo em redes P2P e GPUs constitui uma alternativa que permite melhor desempenho quando comparado à computação sequencial.

I genomsnitt tillbringar människan större delen av sitt liv inomhus och därför är det viktigt med ett bra inomhusklimat. I Swecos kontor i Uppsala finns det ett missnöje med det termiska klimatet vilket är en del av inomhusklimatet. Kontoret är utformat som ett kontorslandskap med stora fönster. Syftet med detta arbete är att få mer kunskap om termiskt klimat vid stora fönster och glasfasader. Målet är att identifiera orsakerna till missnöjet med det termiska klimatet och att ge kunskapsåterkoppling till kommande projekteringar. I arbetet görs en litteraturstudie för att skapa en teoretisk referensram. Efter det så görs en förstudie för att förstå nuläget och få en bild av missnöjet. Beräkningar, simuleringar och mätningar görs för att utesluta och identifiera orsaker till missnöjet. I arbetet gjordes effektberäkningar på värmebalans vilket visade att effektbehovet var tillgodosett i de två zonerna som studerats. Klimatsimuleringar i de två zonerna utfördes i simuleringsprogrammet IDA Klimat och Energi, där resultaten från simuleringarna höll sig inom kravgränser. Något som däremot inte kan simuleras är lufthastigheter. Mätningar på lufttemperatur och yttemperatur utfördes i de två zonerna. I den ena zonen stämde inte mätvärden överens med börvärdet från rumsenheten. I den andra zonen uppskattades fönsterglasets värmegenomgångskoefficient till 1,3 W/(m2K) vilket kan jämföras med den projekterade värmegenomgångskoefficienten för hela fönstret som är 0,8 W/(m2K). Vid beräkning av lufthastighet från kallras i vistelsezonen användes formler från en studie gjord av Heiselberg. Vid en dimensionerande vinterutetemperatur på -19 °C, en innetemperatur på 22 °C och en fönsterhöjd på 2,4 meter låg lufthastigheten på kravgränsen 0,15 m/s med en värmegenomgångskoefficient på 0,8 W/(m2K) och över kravgränsen med en värmegenomgångskoefficient på 1,3 W/(m2K). Slutligen visade resultaten från arbetet att i den första zonen identifierades orsaken till missnöjet med att styrningen av de klimatstyrande installationerna inte fungerade som tänkt. I den andra zonen identifierades orsaken till missnöjet med att ingen värmekälla användes under fönster för att motverka kallras. Värmekälla under fönster skulle behövas enligt beräkningar från arbetet och enligt litteraturstudien som gjordes i arbetet. Med material från arbetet skapas ett dokument om kallras som kunskapsåterföring till Sweco. Nyckelord: Termiskt klimat, Klimatsimulering, Värmebalans, Kallras, Stora fönster / On average, humans spend most of their life indoors and that is why it is so important to have a good indoor climate. At Sweco ́s office in Uppsala there is a dissatisfaction with the thermal climate, which is a part of the indoor climate. The office is designed with an office landscapes and large windows. The purpose with this project is to get more knowledge about thermal climate within large windows and glass facades. The goal with this project is to identify the reasons for the dissatisfaction with thermal climate and to provide knowledge feedback to the company’s future projects. In the project, a literature study is being conducted to create a theoretical framework. After that, a preliminary study is made to understand the current situation and to get a picture of the dissatisfaction. Calculations, simulations and measurements are made to exclude and identify reasons for the dissatisfaction. In the project calculations on heat balances were made and the calculations showed the power requirement was met in the two zones studied. Climatic simulations in the two zones were conducted in the simulation software IDA Indoor Climate and Energy, where the results from the simulations were within limits. However, something that cannot be simulated is air velocities. Measurements of air temperature and surface temperature were performed in the two zones. In one zone, the measured values did not match the set point from the room unit. In the other, the window glass heat transfer coefficient was estimated to be 1,3 W/(m^2)K, which is comparable to the projected heat transfer value for the entire window, which is 0,8 W/(m^2)K. When calculating air velocity from cold downdraught in the residential zone, Heiselberg formulas were used. At an outdoor design temperature for winter of -19 degrees Celsius, an indoor temperature of 22 degrees Celsius and a window height of 2,4 meters, the air velocity result at the 0,15 m/s limit when the heat transfer value was 0,8 W/(m^2)K and resulting in a value above the limit when the heat transfer value was 1,3 W/(m^2)K. Finally, the results showed that in the first zone, the reason for the dissatisfaction was identified with the fact that the control of the climate control installations did not work as intended. In the second zone, the reason for the dissatisfaction was identified that no heat source was used under windows to prevent cold downdraught. Heat source under windows would be needed according to calculations from work and according to the literature study that was done in this work. With material from the work, a document is created about cold downdraught as knowledge feedback to Sweco. Keywords: Thermal climate, Climate simulation, Heat balance, Cold downdraught, Cold downdraft, Large windows

Les flux turbulents à l’interface air-mer représentent le lien entre l’océan et l’atmosphère et jouent donc un rôle majeur dans le système climatique. Dans les modèles de climat, les processus turbulents sont des processus sous-maille, non résolus explicitement, et doivent donc être paramétrés. Ils sont estimés à partir des variables d’états atmosphériques et océaniques au moyen de modèles mathématiques qu’on nomme « paramétrisations bulk ». Ce travail de thèse a pour objectif de caractériser et comprendre les liens entre la représentation des flux turbulents à l’interface air-mer et le fonctionnement d’un modèle de climat à différentes échelles de temps dans les régions tropicales. Pour étudier ces liens, j’ai développé une stratégie de modélisation utilisant un modèle 1D atmosphérique (SCM), un modèle de circulation générale océanique (OGCM) où atmosphérique (AGCM) et un modèle couplé (GCM). L’analyse des simulations SCM permet d’étudier la réponse directe d’un modèle à la modification de la paramétrisation des flux turbulents. On montre que cette dernière régule la quantité d’eau, d’énergie et de quantité de mouvement disponible pour le système et donc son fonctionnement. Elle représente plus de 60% des différences de flux de chaleur latente simulées entre deux modèles de climat dans les périodes convectives. L’impact spatial de la paramétrisation des flux turbulents est étudié au travers des simulations AGCM. Elles mettent en évidence le lien entre la paramétrisation, son effet sur les gradients d’humidité et de température à grande échelle, et donc son influence sur la circulation atmosphérique. L’étude des simulations OGCM souligne quant à elle le rôle principal du vent pour le fonctionnement des océans tropicaux. Si le vent pilote les variations de SST dues à son impact sur la dynamique océanique et principalement sur le sous-courant équatorial, l’humidité, la température et les flux radiatifs n’influencent quant à eux que la surface océanique et sont donc d’une moindre importance. Enfin, l’analyse des simulations GCM met en évidence les rétroactions et l’ajustement engendrés par la modification des flux turbulents. Lors du couplage des deux composantes l’océan agi comme un tampon et absorbe la modification des flux turbulents ce qui entraine une modification de la SST. L’ajustement qui se produit entraine une modification des variables atmosphériques qui amène à un nouvel état d’équilibre du système. La paramétrisation des flux turbulents de surface agit au premier ordre sur l'équilibre énergétique d'un modèle couplé et peut donc amener à des climats simulés différents. Cette étude étant centrée sur les tropiques, une perspective intéressante serait d’étendre l’étude de la représentation des flux turbulents à d’autres échelles spatio-temporelles (i.e. zones extratropicales/fréquence journalière). Cela permettrait de valider le fonctionnement systématique des paramétrisations définies dans cette thèse à l’échelle globale. / The turbulent fluxes at the air-sea interface represent the link between the ocean and the atmosphere and therefore play a major role in the climate system. In climate models, turbulent processes are subgrid scale processes, not explicitly resolved, and must therefore be parameterized. They are estimated from atmospheric and oceanic state variables using mathematical models called “bulk parameterizations”. This thesis aims to characterize and understand the links between the representation of turbulent fluxes at the air-sea interface and the behavior of a climate model at different time scales in tropical regions. To study these links, I developed a modeling strategy using an atmospheric 1D model (SCM), an oceanic (OGCM) or atmospheric (AGCM) general circulation model and a coupled model (GCM). The analysis of SCM simulations allows us to study the direct response of a model to modifications of the turbulent fluxes parameterization. It is shown that it regulates the amount of water, energy and momentum available to the system and therefore its behavior. It can thus represent more than 60% of simulated latent heat flux differences between two climate models in convective periods. The spatial impact of the parameterization of turbulent fluxes is studied through AGCM simulations. They highlight the link between parameterization, its effect on large-scale moisture and temperature gradients, and thus its influence on atmospheric circulation. The study of OGCM simulations underlines the main role of the wind for the behavior of the tropical oceans. If the wind drives changes in SST due to its impact on ocean dynamics and mainly on the equatorial undercurrent, humidity, temperature and radiative flux only influence the ocean surface and are therefore of lesser importance. Finally, the analysis of GCM simulations highlights the feedbacks and the adjustment generated by the modification of turbulent fluxes. When coupling the two components, the ocean acts as a buffer and absorbs the modification of the turbulent fluxes, which leads to a modification of the SST. The adjustment that occurs causes a modification of the atmospheric variables which leads to a new state of equilibrium of the system. The parameterization of surface turbulent fluxes acts at first order on the energy equilibrium of a coupled model and can therefore lead to different simulated climate state. Since this study is focused on the tropics, an interesting perspective would be to extend the study of the turbulent fluxes representation to other spatio-temporal scales (i.e. extra-tropical areas / daily frequency). This would make it possible to validate the systematic behavior of the parameterizations defined in this thesis on a global scale.