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The effect of trees and grass on the thermal and hydrological performance of an urban areaArmson, David January 2012 (has links)
The process of urbanization dramatically alters the landscape which can have negative effects on the environment, and thereby, places the inhabitants and the city itself at risk. The development of an urban heat island can have severe health implications for city inhabitants during prolonged heat waves. Urbanisation also alters hydrological processes, which can place urban areas at a greater threat of surface flooding during heavy rainfall. As cities are continuing to expand, and as climate change proceeds, these problems are only likely to be exacerbated and there is a need to find ways to reduce these negative effects.This thesis builds upon previous modelling work on the effect of greenspace on the climate and hydrology of Manchester, U.K. The aims were to test the predictions of this model by investigating the effect of trees and grass in reducing surface temperatures and rainfall runoff, and further investigate their effects on air and globe temperatures. Surface, globe, and air temperatures were measured on grass and concrete areas in full sun and tree shade, both under large tree canopies, and below those of a range of street tree species. The rainfall runoff from experimental plots covered in asphalt, asphalt plus a tree and grass, was also investigated. Grass reduced surface temperatures in full sun by up to 24°C, in good agreement with previous models, but permanent tree shade reduced concrete temperatures by almost as much, up to 19°C. Tree shade also reduced globe temperatures by up to 7°C, a reduction which can improve human comfort on hot day. These results indicate that both forms of vegetation will act regionally, reducing the urban heat island effect, but that trees can dramatically improve the local environmental conditions. Street trees reduced surface and globe temperatures by rather less, 12°C and 4°C respectively, though trees with a higher leaf area index provided greater cooling. Because of advection neither trees nor small areas of grass had an effect on local air temperatures.Grass was most effective vegetation type at preventing rainfall runoff, reducing runoff coefficients of the plots from around 60% on asphalt to near zero. However, tree units also reduced the runoff coefficient to around 25%, despite having a canopy that covered only a small proportion of the plot, suggesting that much of the rainfall must have infiltrated into the planting hole. These reductions are higher than predicted by previous modelling, highlighting the importance of greenspace on the hydrology of the urban environment.The results suggest that trees and grass provide complementary environmental benefits in cities, and that the benefits of trees strongly depend on species and planting conditions
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Mitigating Urban Heat Island through Integration of Agriculture in the Built Environment in Arid RegionsGaxiola Camacho, Ivan Eladio January 2016 (has links)
Consequences of human activity in natural environments can be observed in urban phenomena. Urban Heat Island is one of those consequences, it is characterized by higher temperature levels in surface-cover and air in urban centers compared with its surrounding rural areas. UHIs are present in cities of arid ecosystems such as Phoenix and Tucson. Existing urban development trends contribute to UHI episodes. Urban Agriculture (UA) is an emerging environmental strategy and, contrary to traditional and industrial agricultural methods, UA systems provide the option of not using soil, its geometrical arrangement lets grow crops disregarding of extensive surface of land to be consumed. UA systems can be implemented as building fabric components. Urban Agriculture provides access to healthier and economic food, it is more energy efficient and promotes a more vegetarian diet which can eventually contribute diminishing health problems such as obesity and toxicity. A response for achieving a decrease in temperature levels in an urban arid region scenario can be established by demonstrating the following premise: "Urban Heat Island effect in arid regions can be mitigated if vegetated surface in the form of agriculture is properly integrated in the built environment". Research procedures were applied at building scale. Results involved physical objective data acquisition. Research methods required the use of software and thermodynamic tools to measure thermal behavior of samples. The impact of vegetated cover in temperature levels and thermal comfort in an outdoor scenario was digitally simulated. The selected research case contributed as a source of data for comparison and baseline benchmarking of thermodynamic circumstances. Employment of green infrastructure in cities can contribute to the improvement of energy efficiency in buildings and developing self-sufficient communities. Urban agriculture comprises implications and side beneficial environmental consequences in arid habitats beyond decreasing temperature levels in cities, such effects are energy conservation, reducing air pollution, diminishing food security concerns, improving soil quality and runoff wastewater as well as cutting down fossil fuel use in transportation of food. In that sense, future research fields include water quality and availability, innovative emerging materials, climate analysis, societal and cultural value, Net zero development and energy efficiency as well as solid waste management.
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Evaluation of Heat Mapping Techniques – the Case of LinköpingZhao, Pei January 2023 (has links)
Land surface temperature (LST) and mean radiant temperature (MRT) are commonly used as proxies to evaluate urban heat environments. Many scholars use one of them to represent heat exposure when assessing the urban thermal environment. This research fills a research gap by analyzing two meteorological parameters simultaneously through correlation analysis, hotspot analysis, and the distinctive information they respectively express with the results of vulnerable population distribution based on the case of Linköping. Scatter plots are used to explore the correlation between LST and MRT, and hot spot analysis is applied to investigate their spatial patterns through the clusters of hot and cold spots. Furthermore, the distribution of vulnerable populations is assessed and visualized through a vulnerability index. The results show that there is a moderate positive linear correlation between the mean values of LST and MRT for the whole study area. They have different spatial patterns based on the results of the hot spot analysis. The comparison of different meteorological parameters to the vulnerability index also shows variations in high heat risk areas. All of these conclude that LST or MRT could, to some extent, be presented as references to each other; however, they cannot be used interchangeably as proxies for urban heat exposure. When developing urban thermal adaptation strategies, it is necessary for municipalities to select the parameters appropriately according to the purpose and requirements and to understand what the chosen parameters can and cannot convey.
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A Smart WIFI Thermostat Data-Based Neural Network Model for Controlling Thermal Comfort in Residences Through Estimates of Mean Radiant TemperatureLou, Yisheng January 2021 (has links)
No description available.
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Investigating The Relationship Between Mean Radiant Temperature (MRT) And Predicted Mean Vote (PMV) : A case study in a University buildingGodbole, Swapnil January 2018 (has links)
Thermal comfort in an indoor environment is largely dependent on the four environmental and two personal parameters which is most commonly measured by the Predicted Mean Vote (PMV) model developed by Fanger. It has been studied that variations in these parameters beyond a range could lead to discomfort complaints. However, little research has been done on the effect of mean radiant temperature variations and its influence on predicted mean vote and thermal comfort specially in an actual building environment. This study aims to investigate the relationship between mean radiant temperature and predicted mean vote in indoor environment. Using the methods of on-site measurement of indoor environmental parameters and subjective votes on thermal sensation in an educational building; it was found that rise in mean radiant temperature lead to rise in PMV value and discomfort vote amongst occupants seated near glazed façade. A very strong positive correlation was found between mean radiant temperature and PMV near the window side of the room under warm and sunny weather conditions. Analysis of indoor environmental data from the several measurement sessions concluded that rise in mean radiant temperature and PMV was not noticed until there was a direct solar transmission through the window. It is advisable to use solar shading on windows, but special consideration should be given to the trade-offs between energy consumption (heating or cooling) and lighting energy consumption. No conclusions could be made in terms of ankle draft discomfort due to experimental limitations and more research would be required to investigate this phenomenon. / Termisk komfort inomhusmiljö är till stor del beroende av de fyra miljö och två personlig parametrar som oftast mäts av Predicted Mean Vote (PMV) modell som utvecklats av Fanger. Det har studerats att variationer i dessa parametrar utanför en limit kan leda till missnöjeklagomål. Däremot har lite forskning gjorts på effekten av mean radiant tempratur och dess inverkan på predicted mean vote och termisk komfort speciellt i en verklig byggnadsmiljö. Syftet med denna studie är att undersöka sambandet mellan mean radiant tempratur och predicted mean vote i inomhusmiljö. Användning mätmetoderna av inomhusmiljöparametrar och subjektiva röster av termisk komfort uppfattning i en byggnad för utbildning; det konstaterades att stiga i medel leda mean radiant tempratur att stiga i predicted mean vote värde och missnöje rösta bland byggnad brukarna sitter nära glasfasaden. En väldigt positiv korrelation mellan men radiant tempratur och predicted mean vote nära en fönstersida under varma och soliga väder var noterat. Genom att analysera data av inomhusmiljön från de multipla mätningssessionerna konkluderat att ökningen i mean radiant tempratur och predicted mean vote inte märktes tills det fanns en direkt soltransmission genom fönstret. Det är rekommenderar att använda solskydd på fönster, men med tanke på kompromisser mellan energiförbrukning (värme eller kyla) och ljussättning konsumtion. Inga slutsatser kan göras om luftdrag på fotled grund av experimentella begränsningar och mer forskning skulle krävas för att undersöka detta fenomen.
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Návrh zařízení pro měření a hodnocení tepelného stavu prostředí / Device Proposal for Measurement and Evaluation of Environmental Thermal StateJanečka, Jan January 2012 (has links)
The thesis deals with evaluation of the environmental thermal state in closed rooms with people inside the room. The achievement of thermal comfort is related to thermal balance of human body. People are producing heat during their work, which has to be carried away from the body to surrounding area by radiation, convection, conduction, respiration and evaporation. The intensity of heat removal is influenced by environmental parameters, especially by air temperature, mean radiant temperature, air velocity and humidity. Personal factors as energy expenditure of human body and clothing resistance are influencing the intensity of heat removal as well. People are able to influence the thermal comfort by their behaviour in given environment, appropriate clothing and regulation of basic environmental parameters. CSN EN ISO 7730 standard states that environmental parameters should be estimated or measured. The operative temperature is than evaluated from collected data. This operative temperature is defined as the temperature of black enclosed area where the human body will be by convection and radiation sharing the same amount of heat as in real inconsistent environment. Nowadays on the market there is no cheap solution for sensor which is able to evaluate the operating temperature and could be used in buildings. There are a lot of professional sensors which have very high accuracy, but are very expensive. Therefore are mainly used only for research or for single and exceptional measurement of environmental thermal state in rooms. The thesis is therefore focused on proposal of suitable (compact) operative temperature sensor assembled according to valid regulations and standards. Emphasis is placed mainly on the sensor price together with guarantee of sufficient accuracy. The proposed sensor is providing information to control system which is than able to adjust the parameters of environment using appropriate way based on relevant requirements. Here is some space for energy savings due to possible continuous measurement and evaluation of environmental thermal state in different rooms. Therefore, during continuous measurement no unnecessary rooms overheating in winter as well as unreasonable cooling in summer should occur. This research and solution is than reflected in reduction of energy consumption used for building operation and subsequently reduction of the pollutants production. This issue is being watched with increasing interest. Another advantage is that whole system is able to work autonomously without human intervention. People no longer have to continuously adjust air temperature because the control system is able to evaluate the most appropriate adjustments based on objective data obtained from the sensor. The thesis includes subsequent verification of proposed sensor as well as the definition of sensor technical parameters including analysis of measurement uncertainties.
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Analýza stropního vytápění / Analysis of Ceiling HeatingCarbol, Ladislav January 2013 (has links)
Diploma thesis deals with analysis of radiant ceiling heating in VUT dormitories. The work contains a theoretical analysis of radiant and convection heat transmission of ceiling heating. Part of this work is creation of mathematical model for evaluation of variables typical for radiant ceiling heating. Model outposts are compared with data measured on a real building.
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Návrh zařízení pro měření a hodnocení tepelného stavu prostředí / Device Proposal for Measurement and Evaluation of Environmental Thermal StateJanečka, Jan January 2012 (has links)
The thesis deals with evaluation of the environmental thermal state in closed rooms with people inside the room. The achievement of thermal comfort is related to thermal balance of human body. People are producing heat during their work, which has to be carried away from the body to surrounding area by radiation, convection, conduction, respiration and evaporation. The intensity of heat removal is influenced by environmental parameters, especially by air temperature, mean radiant temperature, air velocity and humidity. Personal factors as energy expenditure of human body and clothing resistance are influencing the intensity of heat removal as well. People are able to influence the thermal comfort by their behaviour in given environment, appropriate clothing and regulation of basic environmental parameters. CSN EN ISO 7730 standard states that environmental parameters should be estimated or measured. The operative temperature is than evaluated from collected data. This operative temperature is defined as the temperature of black enclosed area where the human body will be by convection and radiation sharing the same amount of heat as in real inconsistent environment. Nowadays on the market there is no cheap solution for sensor which is able to evaluate the operating temperature and could be used in buildings. There are a lot of professional sensors which have very high accuracy, but are very expensive. Therefore are mainly used only for research or for single and exceptional measurement of environmental thermal state in rooms. The thesis is therefore focused on proposal of suitable (compact) operative temperature sensor assembled according to valid regulations and standards. Emphasis is placed mainly on the sensor price together with guarantee of sufficient accuracy. The proposed sensor is providing information to control system which is than able to adjust the parameters of environment using appropriate way based on relevant requirements. Here is some space for energy savings due to possible continuous measurement and evaluation of environmental thermal state in different rooms. Therefore, during continuous measurement no unnecessary rooms overheating in winter as well as unreasonable cooling in summer should occur. This research and solution is than reflected in reduction of energy consumption used for building operation and subsequently reduction of the pollutants production. This issue is being watched with increasing interest. Another advantage is that whole system is able to work autonomously without human intervention. People no longer have to continuously adjust air temperature because the control system is able to evaluate the most appropriate adjustments based on objective data obtained from the sensor. The thesis includes subsequent verification of proposed sensor as well as the definition of sensor technical parameters including analysis of measurement uncertainties.
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Soustava hodnocení tepelného stavu prostředí a analýza jejich nejistot měření / Evaluation System of Thermal Condition Environment and his Measurement Uncertainties AnalyzeKošíková, Jana January 2013 (has links)
The Ph.D. thesis deals with the evaluation of indoor thermal environment in which people are located. A great attention is paid to the thermal comfort. If a person in a given environment does not feel well, then makes mistakes. Thermal comfort is created many parameters that can be monitored and managed. These parameters include not only temperature but also other parameters such as the mean radiant temperature, operative temperature, humidity and air velocity and the draft. All these parameters can be measured. The standard ČSN EN ISO 7726 is written how and what the parameters are measured. Furthermore, this standard provides requirements for measuring equipment. There are many professional measuring devices. Unfortunately, these devices are very expensive. Therefore are within the project GACR 101/09/H050 - Research on energy- saving equipment to achieve the quality of the indoor environment at our faculty developed sensors for thermal comfort, which have showed comparable accuracy measurements as a professional , but it will be cheaper than professional. Knowledge of real parameters of the developed sensor thermal comfort environment is important, as with any other measurement devices, and also need to verified whether it has the required accuracy. In order to objectively sensors testing were developed two chambers - the testing and calibration chamber. The developed sensors were tested both in the open laboratory, and also in the test chamber. Then uncertainties measurement were calculated from the results of measurements This work deals with the evaluation of thermal comfort, the measurement of parameters of thermal environment, the evaluating the results of measurements and determining the measurement uncertainty of the sensors. In this thesis, based on these results, were recommended suitable sensors for measuring various parameters environment.
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Development of a building energy model and a mean radiant temperature scheme for mesoscale climate models, and applications in Berlin (Germany)Jin, Luxi 07 July 2022 (has links)
In dieser Arbeit wird die Entwicklung eines Gebäudeenergiemodells (BEM) und eines Schemas für die mittlere Strahlungstemperatur ($T_mrt$) vorgestellt, das in das Doppel-Canyon basierte städtische Bestandsschichtsschema (DCEP) integriert ist. Das erweiterte DCEP-BEM Modell zielt darauf ab, eine Verbindung zwischen anthropogener Wärme und dem Stadtklima herzustellen, indem Gebäude in Straßenschluchten einbezogen werden, um die Energieflüsse auf städtischen Oberflächen, die Auswirkungen der anthropogenen Wärme auf die Atmosphäre, die Innenraumlufttemperatur und die Abwärme von Klimaanlagen zu untersuchen. Das DCEP-BEM wird mit dem mesoskaligen Klimamodell COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode, im Folgenden CCLM) gekoppelt und zur Simulation des Winters und Sommers 2018 in Berlin.
Die Auswertung der Wintersimulationen zeigt, dass CCLM/DCEP-BEM den mittleren Tagesverlauf der gemessenen turbulenten Wärmeströme gut reproduziert und die simulierte 2-m-Lufttemperatur und den städtischen Wärmeinseleffekt (UHI) verbessert. Im Sommer bildet das CCLM/DCEP-BEM die Innenraumlufttemperatur richtig ab und verbessert die Ergebnisse für die 2-m-Lufttemperatur und die UHI leicht. Außerdem wird das CCLM/DCEP-BEM angewendet, um die Abwärmeemissionen von Klimaanlagen im Sommer zu untersuchen. Die Abwärmeemissionen der Klimaanlagen erhöhen die Lufttemperatur in Oberflächennähe erheblich. Der Anstieg ist in der Nacht und in hochurbanisierten Gebieten stärker ausgeprägt. Es werden zwei Standorte für die AC-Außengeräte betrachtet: entweder an der Wand eines Gebäudes (VerAC) oder auf dem Dach eines Gebäudes (HorAC). Die Auswirkung von HorAC ist im Vergleich zu VerAC insgesamt geringer, was darauf hindeutet, dass HorAC einen kleineren Einfluss auf die oberflächennahe Lufttemperatur und den UHI hat. Ein Schema für $T_mrt$ wird für das CCLM/DCEP-BEM entwickelt und umfassend validiert. Es wird gezeigt, dass dieses Schema eine zuverlässige Darstellung von $T_mrt$ bietet. / This work presents the development of a building energy model (BEM) and a mean radiant temperature ($T_mrt$) scheme integrated in the urban canopy scheme Double Canyon Effect Parametrization (DCEP). The extended DCEP-BEM model aims to establish a link between anthropogenic heat emissions and urban climate by including the interior of buildings in urban street canyons to investigate the energy fluxes on urban surfaces, the effects of anthropogenic heat on the atmosphere, the evolution of indoor air temperature, and waste heat from air conditioning (AC) systems. DCEP-BEM is coupled with the mesoscale climate model COSMO-CLM (COnsortium for Small-scale MOdelling in CLimate Mode, hereafter CCLM) and applied to simulate the winter and summer 2018 of Berlin.
The evaluation for winter simulations indicates that CCLM/DCEP-BEM reproduces well the average diurnal characteristics of the measured turbulent heat fluxes and considerably improves the simulated 2-m air temperature and urban heat island (UHI). In summer, CCLM/DCEP-BEM accurately reproduces the indoor air temperature, and slightly improves the performance of the 2-m air temperature and the UHI effect. Furthermore, CCLM/DCEP-BEM is applied to explore the waste heat emissions from AC systems in summer. AC waste heat emissions considerably increase the near-surface sensible heat flux and air temperature. The increase is more pronounced during the night and in highly urbanised areas. Two locations for the AC outdoor units are considered: either on the wall of a building (VerAC) or on the rooftop of a building (HorAC). The effect of HorAC is overall smaller compared to VerAC, indicating that HorAC has a smaller impact on the near-surface air temperature and the UHI effect. A $T_mrt$ scheme is developed for CCLM/DCEP-BEM and extensively evaluated. It is shown that this scheme provides a reliable representation of $T_mrt$.
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