M.Sc. / This study compares the electricity consumption of two buildings, of similar architectural design, in Simba Office Park, Sandton, in Johannesburg. One of the buildings (Block AB) has not been retrofitted for energy efficiency, whilst the other building (Block C) is a retrofitted building. The hypothesis postulates that the retrofitted building would use less energy than the non-retrofitted one. The research methodology employed has been used internationally, as in the case reported by Levine et al. (1996), who did a study in the United States of America on retrofitting for achieving energy efficiency. Dong et al. (2005) investigated the energy savings due to the retrofitting of old Singaporean commercial office buildings. In this case, six buildings were compared before and after retrofitting, using utility bill and weather data. There have also been similar studies in China (Xu et al, 2006) and Budapest (Urge-Vorsatz & Novikova, 2008). The Budapest study also unpacked the cost of retrofitting. Using methods advocated by Probst (2004), Yalcintas (2008) and Yalcintas & Kaya (2009) for collecting data on floor space, building parameters and design, this study also collected electricity consumption data based on meter readings for the same blocks over the period March 2009 to April 2010. The retrofitting measures were documented and the associated costs noted. Interviews were conducted with key personnel such as the Central Energy Fund (CEF) House executives, the site electrical engineer, the developer, and Simba Office Park managers. Block AB had the least number of energy-efficient installations. Block C was found to be fully retrofitted, at a cost of more than R4 million. However, the energy management system, required to manage and monitor energy use, was only fully installed by November 2009. The results of this study are significant. It was found that energy consumption for Block C far exceeded that for Block AB. Thus, in this case, retrofitting did not reduce electricity consumption. The results demonstrate that in order to fully understand energy use, data collection and analysis must be ongoing. This verifies the findings of Ali (2008), Armstrong (2009) and Yalcintas & Kaya (2009) who found that we need to shift from managing buildings to managing energy use and assess and verify any recorded savings to ensure energy conservation. Computer-based building management systems play a major role in such management. Such a system was only partially in use in Block C for the duration of the study period. Thus, another finding was that the energy management system needs to be fully operational in real time, or else energy efficiencies cannot be achieved and data sets will be incomplete. This conclusion reflects the findings of Hirst (1980).

Orientador: Luis Augusto Barbosa Cortez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T21:47:29Z (GMT). No. of bitstreams: 1 BaldassinJunior_Ricardo_M.pdf: 12303899 bytes, checksum: eebb86f1faa615631b1652ad9774ddde (MD5) Previous issue date: 2007 / Resumo: O leite é um dos mais importantes produtos da agropecuária nacional, com cerca de 2/3 das propriedades rurais do país destinando-se à pecuária leiteira e com um dos maiores rebanhos do mundo. Apesar da grandiosidade, o setor ainda sofre com a baixa produtividade, os altos custos e a defasagem tecnológica. Como conseqüência, muitos produtores abandonaram suas atividades diante deste novo cenário competitivo. Atualmente, assuntos como uso racional de energia e aplicação intensiva de tecnologia tem sido intensamente discutidos e abordados, e indicados como aspectos importantes para a obtenção de ganhos de produtividade. Desta forma, visou-se neste trabalho avaliar o uso de energia no processamento de leite de três propriedades (leite pasteurizado tipo ¿A¿ e leite cru refrigerado), bem como, a representatividade dos diversos processos no consumo total, assunto este, ainda pouco conhecido e abordado no país. Objetivando ainda, promover a racionalização energética, avaliaram-se os potenciais de aproveitamento de calor de condensação de sistemas de refrigeração existentes para o aquecimento de água de limpeza e higienização, bem como, avaliou-se a viabilidade técnica e econômica da adequação dos sistemas (operação segundo um bomba de calor com geração simultânea de duas fontes térmicas) em substituição ao uso de resistências elétricas. Dentre as proposta, avaliou-se a adequação realizada em um planta piloto em operação. Com o uso de bomba de calor, a redução no consumo total de energia elétrica foi de até 15% com tempos de retorno dos investimentos variando entre 1,3 e 3,7 anos / Abstract: Milk is one of the most important products of Brazilian agriculture, with about 2/3 of the rural properties dedicated to the milkmaid cattle breeding and with one of the largest flocks of the world. In spite of its size, the sector still suffers of low productivity, high costs and tecnological delay. As a consequence, many producers have abandoned its activities before this new competitive technology were introduced. Now, subjects as, the use rational of energy and intensive application of technology has been discussed intensely resulting in productivity gains. In this work , it was seek to evaluate the use of energy for milk processing in three different properties (pasteurized milk type " A " and refrigerated raw milk). It was also evaluated how representativive the several processes in the total consumption were, a problem, still not very well-known and trated in Brazil. To promote the energy rationalization, the potential use of condensation heat of refrigeration systems was evaluated for the cleaning water heating, as well as, the technical and economic viability of the adaptation of the systems was evaluated (operation according to a heat pump with simultaneous generation of cold and heat) in substitution to the use of electric resistances. In the midst of proposals, an adaptation was evaluated in a pilot plant in operation. With the use of heat pumps, there was a decreasing of 15% in the consumption of eletric energy with payback between 1,3 and 3,7 years / Mestrado / Mestre em Engenharia Mecânica