Browsing Dissertations for Intelligent Buildings Design and Automation (IBDAA) by Issue Date
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ItemPerformance Simulation of Single- and Double-Effect Absorption Refrigeration Systems Used for Solar Cooling Applications(The British University in Dubai (BUiD), 2012-11) Al Kaab, Noor Sameer AliCooling is very essential for the various aspects of modern life. One of the important applications is the air conditioning field. With increasing oil prices, alternative ways are needed to ensure energy conservation. One of the promising ways is the solar energy use for cooling. The absorption refrigeration system (ARS), which uses thermal energy, is market available but researches on improving their performance are still needed. In this study, simulation of two design configurations of ARS is performed. These configurations are single- and double-effect ARS. In order to compare the performance predictions of these configurations, similar assumptions are used. Condenser and absorber temperatures are assumed 40 degree C. Evaporator temperature is varied as 4, 5, 6 and 7 degree C and the generator temperature is varied as 100, 110, 120, 130, 140, and 150 degree C. The results for the single-effect ARS show enhanced COP with generator temperature, at any evaporator temperature. The COP of single-effect ARS was highest of 0.693, at generator temperature of 120 degree C and evaporator temperature of 7 degree C. Moreover, the performance degraded with lower evaporator temperature. The simulation study for the double-effect ARS shows that the increase of generator-I temperature from 100 to 150 degree C decreases generator-I thermal energy by 7.52%. Moreover, the increase of generator-I temperature increases the COP, at any evaporator temperature to reach maximum of 1.164 at temperature of 130 degree C and evaporator temperature of 7 degree C. The comparison show that the double-effect ARS has higher COP compared with single-effect, at any evaporator temperature. The percentage increase of COP varies from 49.5% (at generator temperature of 100 degree C and evaporator temperature of 4 degree C) to 68.6% (at generator temperature of 150 degree C and evaporator temperature of 7 degree C). The energy storage tank response is studied based on night and daytime operation. For the night operation, electric heat is used whereas for the daytime operation, the heat is supplied to the tank through solar panels. Simulink models are used to investigate the open loop and closed loop responses of the tank. Moreover, appropriate controller is used. The simulation results showed improved performance with closed system but generally the response of the system is slow. Based on the outcomes of the study, it is recommended to consider other designs of absorption system for simulation. Also, simulation at other absorber and condenser temperatures can be performed. ItemReducing of the Energy Consumption in the Federal Buildings in UAE Using Lighting and Control Technologies(The British University in Dubai (BUiD), 2014-04) Al Awadi, Wafaa YousefUAE has one of the highest electricity consumption per capita in the world. This reflects negatively on the CO2 emissions which is an increasing determination in the UAE. CO2 emissions must be reduced as part of the global effort to reduce the greenhouse gases and mitigate global warming effects. This study aims to reduce the electricity consumptions in the federal buildings in the UAE. This research used to find the best lighting and control technologies that can be used in Federal Buildings in UAE to reduce the total energy consumption by reducing lighting energy consumption as a direct energy and also the HVAC (cooling) energy which is the indirect energy that can be saved depending on saving in lighting energy. Three lighting technology proposals were compared to the existing lighting in MOPW-RAK building. The three proposed lighting technologies were compared to the existing lighting technology in three different areas: Meeting Room, Electromechanical Office, and Corridor. Also, lighting control technologies were also applied to the selected areas in the building and compared to the base case also. The building was simulated in two different simulation software’s: Dialux lighting simulation software and IES-VE building energy efficiency modeling software. Some calculations and comparisons between the results were done. From the results, analysis and comparisons we found that LED lights is the best because it has the highest amount of saving the lighting energy. CFL is the worst solution for our case because it uses magnetic ballast. This is the main reason of the high energy consumption in CFL. It was found that with the use of Occupancy sensors, energy savings were 10%, while for Daylight Sensor and Dimming Systems were 25%. The most expensive option is when using the full power lighting without control Systems. Using energy savings Lighting technologies not only affects lighting energy consumption, but are also affect HVAC energy savings because of the outcome heat from the Lighting technologies. Lighting Control Technology also have an effects on HVAC energy savings because of the relation between the HVAC and Lighting which was proved using IES-VE software which show that the Fraction between Lighting and HVAC is 0.33. In another word, each 1KWH of lighting energy equal 3 KWH of HVAC energy consumptions. ItemOptimization of the Energy Performance in the Hospitality Sector in UAE by Using the Integrated Control Methodology in the Guestrooms(The British University in Dubai (BUiD), 2014-05) AlFaris, FadiThis dissertation aims to study the energy efficiency in the hospitality sector in UAE. It will discuss the energy benchmarking analysis for the lodging buildings to differentiate between the usual practice and best practice in terms of energy performance for the hotels. This research focuses on developing several criteria such as; the hotel’s gross floor area, star classification, building age, occupancy rate, guestrooms number, construction code and regulation and cooling energy source, to appraise the hotel building energy consumption with, by gathering a real energy data and basic building information, normalization of energy use index and analyze these data statistically to ascertain the expected energy performance and consumption in UAE. About 19 hotel buildings energy data was analyzed to provide the energy benchmarking findings in UAE hotels. Besides, the normalized energy use index kWh/m²/year has been concluded for the best, usual and poor practice hotels. It was found after the analysis of the collected data that the normalized EUI ranges between lower than 241.5 kWh/m²/year as a best practice and greater than 361.3kWh/m²/year of the poor energy practice for the hotels constructed after the year of 2003, when more stringent code adopted by Dubai Municipality. Whereas the hotels’ energy data showed higher values for those constructed before 2003, as the normalized EUI varies between lower than 348.4 kWh/m²/year as best practice and greater than 511.1kWh/m²/year. As the hospitality sector in UAE is growing to meet the current and upcoming demand. It would be an important requirement to reduce the gap between the poor, usual and the best energy management practices. In this dissertation, the integrated control strategy for the guestroom has been studied and modeled to present the potential of energy savings that might be achieved by using such integrated techniques. The building energy model in hourly basis has been conducted to assess the energy performance improvement after adopting the proposed system. It shows that at least 31.5% might be improved out of entire energy consumption of the hotel including electricity and gas; 43.2% energy savings for the cooling system and 13.2% for lighting system of the guestroom by installing the integrated control system. ItemThe Environmental Radiation Pollution in Urban Buildings(The British University in Dubai (BUiD), 2015-03) Al Smadi, Wajih BasemIndoor environmental quality is essential in urban buildings. Health of occupants depends greatly on factors related to air quality and space maintenance. However, a new form of pollution has emerged in developed nations due to the excessive use of electric and electronic products. This pollution is caused by the unavoidable emanation of electromagnetic fields in the free air and space penetrating the living organisms and causing adverse health effects over the long term. The design and construction studies do not sufficiently account for the radiation-intoxication issues within the indoor environments due to the lack of awareness on the importance of the electromagnetic radiation field. This dissertation reviews the latest literature on the indoor environmental radiation and its health implications. The research experimental study gives an overview on simple procedures to measure, identify and discuss the RF radiation in two residential apartments. Results of this study are compared to the international standards on exposure limits and addressed accordingly in the analysis. The findings discussion and research outcomes should urge project planners to initiate guidelines and recommendations in order to mitigate radio-frequency fields in indoor environments throughout the design phases. The end-users should also be capable of using measurement methodologies to perform a preliminary assessment of the radiation exposure level at their own premises. ItemImpact of Ventilation on the Thermal Comfort by Operable Window in a Typical UAE Office(The British University in Dubai (BUiD), 2015-04) Ajayan, InduNatural ventilation has been the main feature for maintaining thermal comfort in a space since ages. The research intends to merge the use of natural and artificial ventilation to create a comfortable thermal environment for the occupants of an office. It also helps to reduce the total energy consumption of the building. Statistics suggest that UAE has been considered as one of the major per capita consumers of electricity and water, (Dubai Carbon, 2014). In order to reduce the total energy consumption, a strategy is formulated to use natural ventilation in office space with the use of operable windows. The study was conducted on a typical office building in Dubai, UAE. Integrated Environment Solutions (IES VE 2013) was used to analyze the various configurations on the virtual office created. The main factors that are taken into consideration in this system are the orientation of the opening, type of window, percentage opening of the window, the flow rate of the incoming air, the desired temperature of the occupant and the status of the external environment. An automation profile is created for ventilation so that it is available under the best suited weather conditions to reduce the use of air conditioners by making the interior thermally comfortable to the people. The total favorable hours is taken as the criteria of initial study. Based on these criteria specific cases were chosen to have the configuration for least energy consumption. The research concludes that a reduction of 35.49% in the annual energy consumption can be obtained from a combined ventilation systems. It is also noted that the major saving happens when there are more hours of favorable temperature which is the winter season. The temperature chosen by the occupant plays a major role in the energy reduction criteria. It was noticed that the major energy reduction is obtained by maintaining a proper set point temperature. The ventilation combined system also performs in a similar pattern at a lower level of energy consumption. The difference in the energy consumption between the two systems varies from 3% to 5%. The study concludes with the understanding that the ventilation pattern when incorporated into cooling system reduces the energy consumption but significant energy saving can be done using the right set point temperature. Also it can be noticed that the maximum saving occurs during the winter season. ItemDubai Smart Building Assessment System(The British University in Dubai (BUiD), 2017-06) AL MASRI, RAZAN MOH’D TAREQGuidelines and ranking criteria are very important to evaluate buildings. In order to evaluate and define a building as a smart building there should be a criteria or guideline base. In other words an assessment checklist for the building systems, which could be automated to evaluate major building systems, e.g. (HVAC, lighting, Security, etc..). This study is based on the author’s self-logical thinking and analytical research on the essence of implementing a Smart Building in Dubai. The target is to establish smart building implementation guidelines or ” general criteria “ in order to consider a building “smart”. Furthermore, it is based on a Smart Buildings (SB) Survey with more than 100 participants including (building owners, Smart Building Systems Vendors, Consultant’s Companies and Government Experts) in the Emirates of Dubai. Until now no guidelines or standards were issued on smart systems that should be implemented in the buildings of Dubai. There is no specified framework, code, regulations or even simple guidelines for smart buildings for Dubai’s future buildings vision. Although some private companies do their own research on smart buildings score. There are very limited studies about the minimum requirements for implementing smart building procedures. The feasibility and factors conducted in any smart building and the smart building systems which should be implemented, to consider the building smart. Consequently, there is no smart buildings’ checklist or clear assessment system in Dubai depending on the different buildings types and usages that are being permitted, in Dubai Municipality. The SB Survey was carried out with the support of Dubai Municipality in 2016, in order to study the feasibility of providing a smart building guideline.